Erythromycin is a macrolide broad-spectrum antibiotic that is used to treat infections of the respiratory, gastrointestinal, genitourinary tracts, and skin caused by susceptible bacteria.

Erythromycin Uses:

• Bacterial infections:

  • Used in the treatment of susceptible bacterial infections, including:
    • Legionella pneumophila,
    • S. pyogenes,
    • Some S. pneumoniae,
    • Some S. aureus,
    • M. pneumoniae,
    • diphtheria,
    • pertussis,
    • N. gonorrhoeae,
    • E. histolytica,
    • Chlamydia,
    • Erythrasma,
    • Syphilis, and nongonococcal urethritis, and
    • Campylobacter gastroenteritis;
  • For bowel decontamination, it can be used with neomycin.

• Surgical (preoperative) prophylaxis (colorectal):

  • Colorectal decontamination, in conjunction with other agents, prior to surgical intervention

• Off-Label Use of Erythromycin in Adults:

  • Used in Acne vulgaris
  • Used in Bartonella spp. infections (treatment)
  • Used in Bartonella spp. infections (treatment) in HIV infected patients (adolescents and adults)
  • Used in Chancroid
  • Used in Chronic obstructive pulmonary disease, prevention of exacerbations
  • Used in Endoscopy/esophagogastroduodenoscopy, an adjunctive prokinetic agent
  • Used in Gastroparesis (management)
  • Used in Granuloma inguinale (donovanosis)

Erythromycin Dose in Adults

Note: Due to variations in absorption, 250 mg of erythromycin base or stearate and 400 mg of erythromycin ethylsuccinate generate identical blood levels.

• Base: 250–500 mg every 6–12 hours; the daily maximum is 4 g.
• 400 to 800 mg of ethylsuccinate every 6 to 12 hours, with a daily maximum of 4 g.

Erythromycin Usual dosage range:

• Oral:
  • 15 to 20 mg/kg/day divided into six equal doses
• IV:
  • Lactobionate: 500 mg to 1 g every six hours; the daily limit is 4 g.

Erythromycin Indication-specific dosing:

Dose as an alternative therapy in the Acne vulgaris (off-label):

• Oral: Initial dosage is 250 to 500 mg (base) taken twice daily, then 250 to 500 mg (base) once daily.
• To reduce the growth of bacterial resistance, the shortest possible length should be utilised; review after three to four months.

Erythromycin Dose in the treatment of Bartonella spp infections (bacillary angiomatosis [BA], peliosis hepatis [PH]) (off-label):

• Oral: 500 mg (base) four times per day for three or four months (BA) (PH)
• Although treatment durations are not defined, the IDSA skin and soft tissue infection recommendations propose an initial therapy period of 2 weeks to 2 months for cutaneous BA.

Erythromycin Dose in the treatment of Bartonella spp infections in HIV-infected patients (off-label):

Note: Therapy must last for at least three months; whether it is continued depends on the likelihood of relapse and the patient's clinical status.

• Bacillary angiomatosis, peliosis hepatis, bacteremia, and osteomyelitis:

  • Oral, IV: 500 mg every 6 hours

• Other severe infections (excluding CNS infections or endocarditis):

  • Oral, IV: 500 mg every 6 hours with rifampin

Erythromycin Dose in the treatment of Chancroid (off-label):

• Oral: 500 mg (base) thrice in a day  for weak;
• Note: There are documented isolates with varying degrees of resistance.

Erythromycin Dose in the treatment of uncomplicated Chlamydia trachomatis infection: Oral:

• Urogenital infections (off-label):

  • For a weak person, use 500 mg of base four times per day or 800 mg of ethylsuccinate four times per day.

• Lymphogranuloma venereum (off-label; alternative therapy to doxycycline):

  • Oral: For 21 days, take 500 mg (base) four times each day. (CDC [Workowski 2015])

Erythromycin Dose in the treatment of Chronic obstructive pulmonary disease (COPD), prevention of exacerbations (off label):

• Oral: 250 mg (stearate) twice daily, or 200 to 400 mg (unspecified formulation).

Erythromycin Dose in the treatment of Endoscopy/ esophagogastroduodenoscopy, adjunctive prokinetic agent (off-label):

• IV: 3 mg per kg given once over 30 minutes and between 30 and 90 minutes before the endoscopy, or 250 mg given once over 5 to 30 minutes and between 20 and 30 minutes beforehand.

Erythromycin Dose in the treatment of Gastroparesis (off-label):

• IV: 3 milligrammes per kilogramme given during a 45-minute period every eight hours.
• Oral: 250 to 500 mg (base) three times day before meals for patients who are resistant to or intolerable to other prokinetic medicines (such as domperidone, metoclopramide).
• Reduce the length of treatment because tachyphylaxis could start after 4 weeks.

Erythromycin Dose in the treatment of Granuloma inguinale (donovanosis) (off-label):

• Oral: Lesions must disappear after at least 21 days of using 500 mg (base) four times each day.

Note: Gentamicin addition may be recommended if symptoms do not get better after the first few days of treatment.

Erythromycin Dose in the treatment of Impetigo: Oral:

• Base: Depending on how well the treatment works, 250 mg four times each day for a week.
• Ethylsuccinate: Depending on the response, 400 mg four times per day for a weak person

Erythromycin Dose in the treatment of Legionnaire disease:

• Oral: 1.6 to 4 g of ethylsuccinate or 1 to 4 g of base, given over the course of 21 days in divided doses. Note: Only used for patients who are not hospitalised and is no longer the preferred therapy.

Erythromycin Dose in the treatment of Nongonococcal urethritis: Oral:

• For a weak person, use 500 mg of base four times per day or 800 mg of ethylsuccinate four times per day.
• Manufacturer's labeling: Ethylsuccinate 800 mg three times each day. Note: You may take 400 mg of ethylsuccinate or 250 mg of base four times per day.
  • Base: Current clinical practise might not be reflected in the dosing in the prescribed information.
  • Ethylsuccinate: 500 mg (base), 4 times daily or every other day tablets of 333 mg (base) every eight hours

Erythromycin Dose in the treatment of Pertussis:

• Oral: for two weeks, 500 mg (base) every six hours.

Erythromycin Dose in the treatment of Surgical (preoperative) prophylaxis (colorectal) (off-label dose):

• Oral: The day before an 8 AM surgery, 1 g of erythromycin base was administered three times at 1, 2, and 11 o'clock in the evening, along with oral neomycin for mechanical cleaning of the large intestine.
• On the day of operation, perioperative IV antibiotics are also administered.

Erythromycin Dose in Children

Erythromycin General dosing in susceptible infections:

• Infants, Children, and Adolescents:

  • Manufacturer's labeling:

    • Oral: Base, ethylsuccinate, stearate:
      • Commonly divided into doses of 30 to 50 mg per kg per day every 6 to 8 hours;
      • for severe infection double the dose;
      • The maximum daily dose:
        • Mild to moderate infection: 2,000 mg per day;
        • severe infection: 4,000 mg per day
    • IV: Lactobionate:
      • 15 to 20 milligrammes per kg divided into six doses per day;
      • maximum daily dose: 4,000 mg per day

  • Alternate dosing:

    • Mild to moderate infection:
      • Oral: 50 mg per kg divided into six to eight doses per day;
      • maximum daily dose: 2,000 mg per day
    • Severe infection:
      • IV: Lactobionate: Every six hours at a dose of 5 mg per kg
      • maximum daily dose: 4,000 mg per day

Erythromycin Dose in the treatment of moderate to severe Acne:

• Children and Adolescents:

  • Oral: In conjunction with topical therapy (such as benzoyl peroxide), use 250 to 500 mg once or twice daily. The daily maximum dose is 50 mg per kilogramme.
  • Most often, it takes 4 to 8 weeks of therapy to assess the initial clinical response, and it takes longer (3 to 6 months) for the maximum benefit. Resistance to medication is an issue, therefore it's usually only used on youngsters under the age of 8 who can't take tetracycline derivatives.

Dose in the treatment of cutaneous community-acquired Anthrax:

• Infants, Children, and Adolescents:

  • Oral:
    • 10 mg per kg per dosage given every six hours; in most situations, a five- to nine-day course of treatment is sufficient.
  • IV:
    • 20 to 40 milligrammes per kilogramme divided into six doses per day;
    • 4,000 mg is the daily maximum dosage;
    • A 5- to 9-day course of therapy is usually sufficient.

Erythromycin Dose in the treatment of Bartonella sp infections [bacillary angiomatosis (BA), peliosis hepatis (PH)]:

• Treatment of Non-HIV-exposed/-positive:

  • Infants, Children, and Adolescents:
    • Oral: Ethylsuccinate: 10 mg per kg per  dose 4 times a day;
    • The maximum daily dose: 2,000 mg per day;
    • Treatment duration: BA: 3 months; PH: 4 months.

• HIV-exposed/-positive:

  • Prophylaxis:

    • Infants and Children (CDC 2009):
      • Oral: The highest daily dose is 2,000 mg per day, which is divided into 2 to 4 doses per day at 30 to 50 mg per kg.

  • Treatment:

    • Infants and Children:
      • Oral:
        • Therapy will last for three months or longer (of sufficient duration to prevent relapse)
        • 2,000 mg per day is maximum daily dose
      • IV:
        • A  daily dose of 30 to 50 mg per kg, split into 2 to 4 doses;
        • 2,000 mg per day is maximum daily dose
    • Adolescents:
      • IV, Oral: 4 dosages of 15 to 50 mg per kg per day are administered;

Erythromycin Dose in the treatment of Catheter (peritoneal dialysis); exit-site or tunnel infection:

• Infants, Children, and Adolescents:

  • Oral (base): 30 to 50 mg per kg divided into 3 to 4 doses throughout the day;
  • 500 mg per dose is maximum dose

Erythromycin Dose in the treatment of Chlamydia trachomatis infection:

• Conjunctivitis or pneumonia:

  • Infants, Children, and Adolescents:
    • oral (base or ethylsuccinate): 50 mg per kg per day split into six-hour intervals for 14 days; the daily maximum dose is 2,000 mg;
    • For severe trachoma, a repeat session or prolonged durations may be required (40 days).

Erythromycin Dose in the treatment of Anogenital tract infection:

• Children and Adolescents <45 kg:

  • Oral (base or ethylsuccinate): 50 mg per kilogramme divided into six equal doses each day for 14 days;
  • 2,000 mg per day is maximum daily dose

• Adolescents ≥45 kg: Oral:

  • Base: For a weak, take 500 mg four times per day.
  • Ethylsuccinate: For a weak, take 800 mg four times per day.

Erythromycin Dose in the treatment of Lymphogranuloma venereum (LGV):

• Adolescents ≥45 kg:

  • Oral (base): 4 times a day for 21 days at 500 mg

Erythromycin Dose in the treatment of Impetigo:

• Infants, Children, and Adolescents:

  • Oral: 10 mg per kg per dose 4 times in  a day (Stevens 2005)

Erythromycin Dose in the treatment of Lyme Disease:

• Infants, Children, and Adolescents:

  • Oral: 50 mg per kg each day split into six hours for a period of 14 to 21 days;
  • 500 mg is maximum dose

Erythromycin  Dose in the treatment of Pertussis:

• Infants 1 to 5 months:

  • Oral: for two weeks, 4 times a day 10 mg per kg per dose

• Infants ≥6 months and Children:

  • Oral: for 7 to 14 days, 10 mg per kg per dose 4 times 
  • 2,000 mg per day is maximum daily dose

• Adolescents:

  • Oral: for 7 to 14 days, 500 mg 4 times 

Erythromycin Dose in the treatment of community-acquired Pneumonia, (CAP):

• Infants >3 months, Children, and Adolescents:

Note: If normal bacterial pneumonia cannot be ruled out, a beta-lactam antibiotic should be added.

• • Presumed atypical (M. pneumoniae, C. pneumoniae, C. trachomatis); mild infection or step-down therapy:
    • Oral: Every six hours, 10 mg per kilogramme is administered; the daily maximum dose is 2,000 mg.
  • Moderate to severe atypical infection:
    • IV: Lactobionate: every 6 hours, 5 mg per kg per dose;
    • 4,000 mg per day is maximum daily dose

Erythromycin Dose in the treatment of Preoperative bowel preparation:

• Children and Adolescents:

  • Oral: Base: 20 mg per kg;  On the day before surgery, 1,000 mg were given at 1, 2, and 11 PM along with oral neomycin and mechanical cleaning of the large intestine.

Erythromycin Dose in the treatment of Prokinetic (GI motility) agent:

• Infants, Children, and Adolescents:

  • Diagnosis; gastric emptying study (provocative testing):

    • IV:
      • 2.8 mg per kg given over a period of 20 minutes, according to one center's observations;
      • 250 mg is maximum dose
    • Treatment:
      • Oral: 3 mg per kg, given once. 4 times per day; may increase as necessary to achieve impact;
      • the maximum dose is 250 mg or 10 mg per kg.

Pneumococcal prophylaxis in penicillin-allergic patients with sickle cell disease (SCD) and functional or anatomic asplenia: Oral:

• Infants and Children: 4 months to <3 years:

  • 125 mg two times a day; salt not specified

• Children 3 to 4 years:

  • 250 mg two times day; salt not specified

Pregnancy Risk Factor B

• It can also cross the placenta.
• It is a preferred antibiotic for preterm, prelabor membrane ruptures (34 0/7 weeks gestation), therapy of pregnancy-related lymphogranuloma, and long-term suppression. Bartonella infection in pregnant HIV-positive patients
• Some observational studies have shown that early exposure to radiation can lead to cardiovascular anomalies.
• Pregnant women may have different serum concentrations of erythromycin.
• It can be used to treat chancroid and granuloma ingguinale in pregnancy.

Use during breastfeeding:

• It can be found in breast milk.
• Breastfeeding infants who have been exposed to macrolide anti-biotics have experienced diarrheal, rash, nausea, vomiting, and somnolence.
• After erythromycin exposure, symptoms such as irritability and discoloration of the stool have been reported.
• The likelihood of a link between erythromycin-induced pyloric blockage in neonates who were administered breastfeeding erythromycin is suggested by a cohort research and a case report.
• Breastfeeding mothers may prefer an alternative antibiotic to this drug.
• Breast milk antibiotics can cause non-dose-related changes in the bowel flora.
• Monitor infants for GI disorders such as thrush or dehydration.
• Erythromycin is the preferred treatment for granuloma and lymphogranuloma venereum among breastfeeding females.
• It is not recommended to use systemic erythromycin for dermatologic conditions. However, breastfeeding is a good option.
• The manufacturer suggests caution when administering erythromycin to a nursing female. However, the usual recommended doses of erythromycin are considered compatible.

Dose in Kidney Disease:

There are no dosage modifications specified on the labelling from the manufacturer.

• Dialysis:
  • Slightly dialyzable (5% to 20%).
  • In hemo- or peritoneal dialysis, as well as in continuous arteriovenous or venovenous hemofiltration, the additional dose is not required.

Dose in Liver disease:

There are no dosage modifications specified on the labelling from the manufacturer. In patients with hepatic impairment, use with caution.

Side effects of erythromycin:

Incidence may vary with the formulation.

• Cardiovascular:

  • QT Prolongation
  • Ventricular Tachycardia
  • Torsade De Pointes
  • Ventricular Arrhythmia

• Central Nervous System:

  • Seizure

• Dermatologic:

  • Erythema Multiforme
  • Pruritus
  • Urticaria
  • Skin Rash
  • Stevens-Johnson Syndrome
  • Toxic Epidermal Necrolysis

• Gastrointestinal:

  • Abdominal Pain
  • Anorexia
  • Diarrhea
  • Nausea
  • Oral Candidiasis
  • Pancreatitis
  • Pseudomembranous Colitis
  • Pyloric Stenosis (Infantile Hypertrophic)
  • Vomiting

• Hepatic:

  • Abnormal Hepatic Function Tests
  • Cholestatic Jaundice (Most Common With Estolate)
  • Hepatitis

• Hypersensitivity:

  • Anaphylaxis
  • Hypersensitivity Reaction

• Local:

  • Injection Site Phlebitis

• Neuromuscular & Skeletal:

  • Weakness

• Otic:

  • Hearing Loss

• Renal:

  • Interstitial Nephritis

Contraindications to Erythromycin:

• Hypersensitivity to erythromycin or macrolide antibiotics.
• Use with cisapride or ergotamine or pimozide or dihydroergotamine in combination

Warnings and precautions

• Modified cardiac conduction

  • Macrolides have been related to rare QTc prolongation, ventricular arrhythmias, and torsade-de-pointes; patients at high risk for prolonged cardiac repolarization should be treated cautiously. Use with caution in individuals with extended QT intervals, untreated hypokalemia and hypomagnesemia, clinically severe bradycardia, or concurrent use of Class IA (e.g., quinidine, procainamide),
  • Class III, or other medications (eg amiodarone dofetilide, sotalol).

• Superinfection

  • Extended use may result in fungal or bacterial overinfections, such as pseudomembranous collitis or diarrhoea caused by Clostridium difficile. CDAD has been observed up to two months after receiving antibiotics.

• Hepatic impairment

  • Patients with liver disease should be cautious. Hepatic impairment (including hepatocellular or cholestatic) has been observed in some patients.
  • If you experience nausea, vomiting or abdominal colic, stop taking the medication.

• Myasthenia gravis:

  • Myasthenia gravis symptoms can be exacerbated or reactivated.

Erythromycin (systemic): Drug Interaction

Note: Drug Interaction Categories:

• Risk Factor C: Monitor When Using Combination
• Risk Factor D: Consider Treatment Modification
• Risk Factor X: Avoid Concomitant Use

Risk Factor C (Monitor therapy)
Abemaciclib	CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Abemaciclib.
ALPRAZolam	The systemic erythromycin may raise ALPRAZolam's serum levels.
Apixaban	Apixaban's serum levels may rise when taken with CYP3A4 Inhibitors (Moderate).
AtorvaSTATin	The serum levels of AtorvaSTATin may rise when erythromycin (Systemic) is used.
ARIPiprazole	The serum levels of ARIPiprazole may rise in the presence of CYP3A4 Inhibitors (Moderate). Management: Keep an eye out for enhanced pharmacologic effects of aripiprazole. Depending on the concurrent therapy and/or the indication, aripiprazole dosage modifications may or may not be necessary. For detailed advice, refer to the complete interaction monograph.
BCG Vaccine (Immunization)	Antibiotics may reduce the BCG vaccine's therapeutic effect (Immunization).
Benzhydrocodone	The serum levels of Benzhydrocodone may rise in response to moderate CYP3A4 inhibitors. In particular, there might be an increase in hydrocodone concentration.
Blonanserin	Blonanserin's serum levels may rise when taken with CYP3A4 Inhibitors (Moderate).
Bosentan	May lower the serum level of CYP3A4 substrates (High risk with Inducers).
Bosentan	The serum levels of bosentan may rise after taking CYP3A4 Inhibitors (Moderate). Management: It is not advised to take a CYP2C9 and CYP3A inhibitor concurrently, or a single medication that inhibits both enzymes, with bosentan because this will likely result in a significant rise in the drug's serum level. Monograph for more information.
Brentuximab Vedotin	The serum concentration of Brentuximab Vedotin may rise in response to P-glycoprotein/ABCB1 Inhibitors. More specifically, levels of the substance's active monomethyl auristatin E (MMAE) component might rise.
Brexpiprazole	Brexpiprazole's serum levels may rise in the presence of moderate CYP3A4 inhibitors. Treatment: If brexpiprazole is used with a moderate CYP3A4 inhibitor and a strong or moderate CYP2D6 inhibitor, or if a moderate CYP3A4 inhibitor is used in a CYP2D6 poor metabolizer, the dose should be lowered to 25% of the usual amount.
Cannabidiol	Cannabidiol's serum levels may rise in response to moderate CYP3A4 inhibitors.
Cannabis	Cannabis serum concentrations may rise in response to moderate CYP3A4 inhibitors. Serum concentrations of cannabidiol and tetrahydrocannabinol may rise particularly.
Cardiac Glycosides	The serum levels of cardiac glycosides may rise in response to macrolide antibiotics.
Celiprolol	Celiprolol's serum levels may rise in response to P-glycoprotein/ABCB1 inhibitors.
Ceritinib	The QTcprolonging impact of ceritinib may be enhanced by moderate risk QT-prolonging CYP3A4 inhibitors. Ceritinib may increase the effect of moderate CYP3A4 inhibitors that prolong QT in a QTc-prolonging manner (Moderate Risk). Ceritinib's blood levels may rise in response to moderate CYP3A4 inhibitors with a QT prolonging effect (Moderate Risk). When using these medications together, watch out for cardiac arrhythmias and a prolonged QTc interval. Patients may be considerably more at risk for QTc prolongation if they have additional risk factors.
Citalopram	Possibly amplifies the QTc-prolonging effects of moderate CYP3A4 inhibitors (Moderate Risk). Citalopram's serum levels may rise in response to moderate CYP3A4 inhibitors with a QT prolonging effect (Moderate Risk).
Clopidogrel	Erythromycin (Systemic) may lessen Clopidogrel's antiplatelet action.
Codeine	The active metabolite(s) of codeine may be present in lower serum concentrations while taking CYP3A4 Inhibitors (Moderate).
Crizotinib	Crizotinib's QTc-prolonging action may be enhanced by moderate risk moderate CYP3A4 inhibitors. Crizotinib's serum levels may rise in response to moderate CYP3A4 inhibitors that extend the QT interval (Moderate Risk). Management: When these medications are combined, keep an eye out for QTc interval prolongation and cardiac arrhythmias. Patients may be considerably more at risk for QTc prolongation if they have additional risk factors.
CycloSPORINE (Systemic)	Systemic erythromycin may elevate serum levels of cycloSPORINE (Systemic).
CYP3A4 Inducers (Moderate)	May lower the serum level of CYP3A4 substrates (High risk with Inducers).
CYP3A4 Substrates (High risk with Inhibitors)	The metabolism of CYP3A4 Substrates may be decreased by moderate CYP3A4 Inhibitors (High risk with Inhibitors). Alitretinoin (Systemic), Praziquantel, Trabectedin, and Vinorelbine are exceptions.
Deferasirox	May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers).
Doxofylline	Erythromycin (Systemic) may increase the serum concentration of Doxofylline.
Dronabinol	CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Dronabinol.
Erdafitinib	May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers).
Erdafitinib	May increase the serum concentration of P-glycoprotein/ABCB1 Substrates.
Estrogen Derivatives	CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Estrogen Derivatives.
Fexofenadine	The serum levels of Fexofenadine may increase when Erythromycin (Systemic) is used.
Haloperidol	QT-prolonging Moderate The QTc-prolonging effects of haloperidol may be enhanced by CYP3A4 Inhibitors (Moderate Risk). When using these medications together, watch out for cardiac arrhythmias and a prolonged QTc interval. Patients with additional risk factors for QTc prolongation may be at even higher risk.
HYDROcodone	CYP3A4 Inhibitors (Moderate) may raise the level of Hydrocodone in the blood.
Ifosfamide	The active metabolite(s) of ifosfamide may be present in lower serum concentrations when CYP3A4 Inhibitors (Moderate) are used.
Imatinib	CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Imatinib.
Lactobacillus and Estriol	The therapeutic effects of Lactobacillus and Estriol may be reduced by antibiotics.
Larotrectinib	P-glycoprotein/ABCB1 Inhibitors may raise larotrectinib's serum levels.
Mirodenafil	The serum concentration of Mirodenafil may rise in response to CYP3A4 Inhibitors (Moderate).
Naldemedine	Naldemedine's serum levels may rise in response to CYP3A4 Inhibitors (Moderate).
Naldemedine	The serum concentration of Naldemedine may rise in response to P-glycoprotein/ABCB1 Inhibitors.
Nalfurafine	Nalfurafine's serum levels may rise in response to CYP3A4 Inhibitors (Moderate).
Nintedanib	Combination CYP3A4 and P-glycoprotein inhibitors may raise the level of Nintedanib in the blood.
Ondansetron	Possibly amplifies the QTc-prolonging effects of moderate CYP3A4 inhibitors (Moderate Risk). When using these medications together, watch out for cardiac arrhythmias and a prolonged QTc interval. Patients may be considerably more at risk for QTc prolongation if they have additional risk factors.
Oxybutynin	The serum levels of Oxybutynin may rise when Erythromycin (Systemic) is used.
OxyCODONE	CYP3A4 Inhibitors (Moderate) may intensify OxyCODONE's harmful/toxic effects. The serum concentration of OxyCODONE may rise in response to moderately potent CYP3A4 inhibitors. The active metabolite Oxymorphone's serum concentrations could also rise.
Pentamidine (Systemic)	Possibly amplifies the QTc-prolonging effects of moderate CYP3A4 inhibitors (Moderate Risk). When using these medications together, watch out for cardiac arrhythmias and a prolonged QTc interval. Patients may be considerably more at risk for QTc prolongation if they have additional risk factors.
P-glycoprotein/ABCB1 Inhibitors	Pglycoprotein/ABCB1 Substrates serum levels can rise. Additionally, p-glycoprotein inhibitors may improve the distribution of pglycoprotein substrates to particular cells, tissues, and organs where high levels of p-glycoprotein are present (e.g., brain, T-lymphocytes, testes, etc.).
P-glycoprotein/ABCB1 Substrates	The serum concentration of P-glycoprotein/ABCB1 Substrates may rise in response to P-glycoprotein/ABCB1 Inhibitors. P-glycoprotein inhibitors may also make it easier for p-glycoprotein substrates to reach particular cells, tissues, and organs where p-glycoprotein is abundant (e.g., brain, T-lymphocytes, testes, etc.). Loperamide is an exception.
Pimecrolimus	The metabolism of pimecrolimus may be decreased by moderate CYP3A4 inhibitors.
Pivmecillinam	Erythromycin (Systemic) may lessen Pivmecillinam's therapeutic efficacy.
Pravastatin	The serum levels of Pravastatin may rise when Erythromycin (Systemic) is used.
QT-prolonging Antidepressants (Moderate Risk)	May increase the effect of moderate CYP3A4 inhibitors on QTc prolongation (Moderate Risk). Citalopram is an exception.
QT-prolonging Antipsychotics (Moderate Risk)	QT-prolonging QT-prolonging antipsychotics may have an enhanced QTc-prolonging impact when used with moderate CYP3A4 Inhibitors (Moderate Risk) (Moderate Risk). When using these medications together, watch out for cardiac arrhythmias and a prolonged QTc interval. Patients may be considerably more at risk for QTc prolongation if they have additional risk factors. Examples include pimozide.
QT-prolonging Class IC Antiarrhythmics (Moderate Risk)	Possibly amplifies the QTc-prolonging effects of moderate CYP3A4 inhibitors (Moderate Risk). When using these medications together, watch out for cardiac arrhythmias and a prolonged QTc interval. Patients may be considerably more at risk for QTc prolongation if they have additional risk factors.
QT-prolonging Kinase Inhibitors (Moderate Risk)	The QTc-prolonging action of QT-prolonging Kinase Inhibitors may be enhanced by QT-prolonging Moderate CYP3A4 Inhibitors (Moderate Risk) (Moderate Risk). The serum concentration of QT-prolonging Kinase Inhibitors may rise in response to QT-prolonging Moderate CYP3A4 Inhibitors (Moderate Risk) (Moderate Risk). Encorafenib is a rare case.
QT-prolonging Miscellaneous Agents (Moderate Risk)	The QTc-prolonging action of QT-prolonging Miscellaneous Agents may be enhanced by QT-prolonging Moderate CYP3A4 Inhibitors (Moderate Risk) (Moderate Risk). QT-prolonging Miscellaneous Agents' serum concentration may be increased by QT-prolonging Moderate CYP3A4 Inhibitors (Moderate Risk) (Moderate Risk). When using these medications together, watch out for cardiac arrhythmias and a prolonged QTc interval.
QT-prolonging Moderate CYP3A4 Inhibitors (Moderate Risk)	Erythromycin (Systemic) may increase the effect of moderate CYP3A4 inhibitors that cause QTc prolongation (Moderate Risk). When using these medications together, watch out for cardiac arrhythmias and a prolonged QTc interval. Patients may be considerably more at risk for QTc prolongation if they have additional risk factors. Ceritinib, Crizotinib, and Fluconazole are exceptions.
QT-prolonging Quinolone Antibiotics (Moderate Risk)	Possibly amplifies the QTc-prolonging effects of moderate CYP3A4 inhibitors (Moderate Risk). When using these medications together, watch out for cardiac arrhythmias and a prolonged QTc interval. Patients may be considerably more at risk for QTc prolongation if they have additional risk factors.
QT-prolonging Strong CYP3A4 Inhibitors (Moderate Risk)	Erythromycin (Systemic) may increase the effect of strong CYP3A4 inhibitors that prolong QT by lengthening QTc (Moderate Risk). When using these medications together, watch out for cardiac arrhythmias and a prolonged QTc interval. Patients who have additional QTc prolongation risk factors may be at greater risk.
Repaglinide	The serum levels of Repaglinide may rise when Erythromycin (Systemic) is used. Management: The extent of the rise in repaglinide exposure may be significantly increased by adding a CYP2C8 inhibitor to this medication combination.
RifAXIMin	The concentration of RifAXIMin in the serum may rise in response to P-glycoprotein/ABCB1 inhibitors.
Rupatadine	Rupatadine's serum levels may rise in response to moderate CYP3A4 inhibitors.
Ruxolitinib	Ruxolitinib's serum levels may rise when taken with CYP3A4 Inhibitors (Moderate).
Salmeterol	Salmeterol's serum levels may rise in response to CYP3A4 Inhibitors (Moderate).
Sarilumab	May lower the serum level of CYP3A4 substrates (High risk with Inducers).
SAXagliptin	The serum levels of SAXagliptin may rise in response to moderately potent CYP3A4 inhibitors.
Sertraline	Sertraline's harmful or toxic effects may be exacerbated by erythromycin (Systemic).
Silodosin	The serum concentration of Silodosin may rise in response to P-glycoprotein/ABCB1 Inhibitors.
Silodosin	Silodosin's serum levels may rise in response to moderate CYP3A4 inhibitors.
Siltuximab	May lower the serum level of CYP3A4 substrates (High risk with Inducers).
Tacrolimus (Systemic)	The serum levels of Tacrolimus may rise when Erythromycin is taken systemically (Systemic).
Tacrolimus (Topical)	Tacrolimus serum levels may rise in response to macrolide antibiotics (Topical).
Talazoparib	The serum concentration of Talazoparib may rise in response to P-glycoprotein/ABCB1 inhibitors. Management: Separate interaction monographs are written in-depth for each of the above exceptions.
Tamsulosin	Tamsulosin's serum levels may rise when taken with CYP3A4 Inhibitors (Moderate).
Telithromycin	CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Telithromycin.
Tetrahydrocannabinol	CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Tetrahydrocannabinol.
Ticagrelor	CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Ticagrelor.
Tocilizumab	May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers).
Trabectedin	CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Trabectedin.
Udenafil	The serum levels of udenafil may rise in response to CYP3A4 Inhibitors (Moderate).
Vilazodone	Vilazodone's serum levels may rise when taken with CYP3A4 Inhibitors (Moderate).
Vitamin K Antagonists (eg, warfarin)	The serum concentration of Vitamin K antagonists may rise in response to macrolide antibiotics.
Zafirlukast	The serum concentration of Zafirlukast may drop when Erythromycin (Systemic) is used.
Zuclopenthixol	The serum levels of Zuclopenthixol may rise in response to CYP3A4 Inhibitors (Moderate).
Risk Factor D (Consider therapy modification)
Acalabrutinib	Acalabrutinib's serum levels may rise when taken with CYP3A4 Inhibitors (Moderate). Treatment: Lower the dose of acalabrutinib to 100 mg once daily while using a mild CYP3A4 inhibitor. If there is any concurrent use, keep a watchful eye on the patient for both acalabrutinib response and signs of side effects.
Afatinib	P-glycoprotein/ABCB1 Inhibitors may raise the level of Afatinib in the serum. Management: If afatinib is not tolerated, reduce the dose by 10 mg, as per US labelling. Avoid combinations if at all feasible; if necessary, deliver the P-gp inhibitor along with the afatinib dose or just after it.
Alfentanil	The systemic form of erythromycin may raise alfentanil's serum levels. Treatment: When giving alfentanil to patients who are also taking erythromycin, care should be taken to avoid causing an increase in anaesthetic or respiratory depressive effects. Alfentanil dosages should be reduced, or an alternate anaesthetic should be used.
Antineoplastic Agents (Vinca Alkaloids)	The serum concentration of antineoplastic agents may rise in response to macrolide antibiotics (Vinca Alkaloids). Macrolides may also spread vinca alkaloids more widely throughout some tissues and/or cell types. When feasible, avoid using a macrolide antibiotic in order to minimise the risk of infection.
Avanafil	Avanafil's serum levels may rise in response to moderate CYP3A4 inhibitor therapy. Management: When used with a mild CYP3A4 inhibitor, the maximum adult dose of avanafil is 50 mg per 24 hours. Additionally, patients receiving this combination should be watched more attentively for signs of side effects.
Betrixaban	The serum concentration of betrixaban may rise in response to P-glycoprotein/ABCB1 inhibitors. Treatment: If betrixaban is used with a P-glycoprotein inhibitor, reduce the dose to an initial single dose of 80 mg, followed by 40 mg once day.
Bilastine	The serum concentration of bilastine may rise in response to P-glycoprotein/ABCB1 inhibitors. Management: When possible, look into alternatives; bilastine should be avoided in patients using p-glycoprotein inhibitors who have moderate to severe renal insufficiency.
Brigatinib	Brigatinib's serum levels may rise when taken with CYP3A4 Inhibitors (Moderate). Management: When possible, avoid taking brigatinib at the same time as mild CYP3A4 inhibitors. Reduce the brigatinib dosage by around 40% if such a combination cannot be avoided (ie, from 180 mg to 120 mg, from 120 mg to 90 mg, or from 90 mg to 60 mg).
Bromocriptine	The serum levels of bromocriptine may rise in response to moderately potent CYP3A4 inhibitors. Treatment: When used with a mild CYP3A4 inhibitor, the daily dose of bromocriptine should not exceed 1.6 mg. Other bromocriptine medicines do not give as detailed advice as the Cycloset brand does regarding dose restriction.
Budesonide (Topical)	The serum concentration of Budesonide may rise while using moderate amounts of CYP3A4 inhibitors (Topical). Management: Avoid this combination, according to US prescribing advice. Canadian goods labels do not expressly advise against anything. If used in conjunction, keep an eye out for too glucocorticoid effects as budesonide exposure may rise.
BusPIRone	The serum levels of BusPIRone may rise when Erythromycin (Systemic) is used. Management: If coupled with erythromycin, reduce the dose of buspirone to 2.5 mg twice daily and keep an eye out for any increased side effects or toxicities.
Calcium Channel Blockers	Calcium Channel Blockers may have a slower metabolism when using macrolide antibiotics. Use a noninteracting macrolide as a possible management strategy. The Canadian labelling for felodipine expressly advises against using it in conjunction with clarithromycin. Clevidipine is an exception.
CarBAMazepine	The serum levels of CarBAMazepine may rise in response to erythromycin (Systemic). For management, use carbamazepine with an alternate antimicrobial medication. Check for enhanced carbamazepine effects or toxicities if taken together.
Cilostazol	Cilostazol's serum levels may rise in response to CYP3A4 Inhibitors (Moderate). Management: When treating adult patients who are already using mild CYP3A4 inhibitors, think about lowering the dose of cilostazol to 50 mg twice daily.
Colchicine	Colchicine's serum levels may rise after taking CYP3A4 Inhibitors (Moderate). Management: Increase monitoring for colchicine-related toxicity and decrease colchicine dose as advised when used with a moderate CYP3A4 inhibitor. For information, see the entire monograph. Patients with weakened liver or kidney function should be treated with extreme caution.
Colchicine	The serum concentration of colchicine may rise in response to P-glycoprotein/ABCB1 inhibitors. It's possible that colchicine will distribute more widely throughout some tissues, like the brain. Treatment: Patients receiving a p-glycoprotein inhibitor and having compromised renal or hepatic function should not take colchicine. Colchicine dosage should be decreased in patients with normal renal and hepatic function as instructed. For information, see the entire monograph.
CYP3A4 Inducers (Strong)	May speed up CYP3A4 substrate metabolism (High risk with Inducers). Management: Take into account a substitute for one of the interfering medications. Specific contraindications may apply to some combinations. the relevant manufacturer's label.
Dabigatran Etexilate	The serum concentrations of the active metabolite(s) of dabigatran etexilate may rise in response to P-glycoprotein/ABCB1 inhibitors. Reducing the dose of dabigatran may be necessary for treatment. Specific advice varies significantly depending on the indication, renal function, specific P-gp inhibitor, and US vs. Canadian labelling
Dabrafenib	May lower the serum level of CYP3A4 substrates (High risk with Inducers). Management: When possible, look for substitutes for the CYP3A4 substrate. If concurrent therapy cannot be avoided, pay special attention to the substrate's clinical consequences (particularly therapeutic effects).
Dapoxetine	Dapoxetine's serum levels may rise in response to moderate CYP3A4 inhibitors. Treatment: When used with a mild CYP3A4 inhibitor, the daily dose of dapoxetine should be restricted to 30 mg.
Deflazacort	The active metabolite(s) of Deflazacort may be present in higher serum quantities when taking CYP3A4 Inhibitors (Moderate). When taking deflazacort with a strong or moderate CYP3A4 inhibitor, only take one-third of the prescribed dose.
DOXOrubicin (Conventional)	The serum concentration of DOXOrubicin may rise after using moderate amounts of CYP3A4 inhibitors (Conventional). Treatment: Whenever possible, avoid using mild CYP3A4 inhibitors in patients receiving doxorubicin. Pfizer Inc., a U.S. manufacturer, advises against using certain mixtures.
DOXOrubicin (Conventional)	Inhibitors of P-glycoprotein/ABCB1 may raise DOXOrubicin's serum concentration (Conventional). Treatment: Whenever possible, avoid using P-glycoprotein inhibitors in patients receiving doxorubicin. Pfizer Inc., a U.S. manufacturer, advises against using certain mixtures.
Edoxaban	The concentration of Edoxaban in the serum may rise in response to P-glycoprotein/ABCB1 inhibitors. Management: For more, see the whole monograph. Patients taking edoxaban for venous thromboembolism in conjunction with specific P-gp inhibitors are advised to take it in lower doses. It is not advised to modify the dosage when using edoxaban for atrial fibrillation.
Eletriptan	Eletriptan's serum levels may rise when taken with CYP3A4 Inhibitors (Moderate). Management: Eletriptan shouldn't be taken within 72 hours of a moderate CYP3A4 inhibitor.
Eliglustat	Eliglustat's serum levels may rise when taken with CYP3A4 Inhibitors (Moderate). Management: There are specific situations when use should be avoided. For information, consult the entire medication interaction monograph.
Encorafenib	Encorafenib's serum levels may rise when taken with CYP3A4 Inhibitors (Moderate). Management: Whenever possible, refrain from taking moderate CYP3A4 inhibitors and encorafenib concurrently. Reduce the encorafenib dose to 50% of the encorafenib dose used prior to starting the CYP3A4 inhibitor if concurrent administration is unavoidable.
Encorafenib	Possibly amplifies the QTc-prolonging effects of moderate CYP3A4 inhibitors (Moderate Risk). The blood concentration of Encorafenib may rise in response to moderate CYP3A4 inhibitors that prolong QT (Moderate Risk). Management: If at all possible, keep moderate CYP3A4 inhibitors away from encorafenib. Reduce the dosage of encorafenib by 50% if the combo must be used (to one-half of the prior dose).
Enzalutamide	May lower the serum level of CYP3A4 substrates (High risk with Inducers). Treatment: Enzalutamide should not be used concurrently with CYP3A4 substrates that have a limited therapeutic index. Enzalutamide use, like with the use of any other CYP3A4 substrate, should be done cautiously and under close observation.
Eplerenone	Eplerenone's serum levels may rise in response to CYP3A4 Inhibitors (Moderate). Management: Depending on the indication, different eplerenone dosage guidelines should be followed when used with mild CYP3A4 inhibitors.
Ergot Derivatives	Ergot derivatives' serum levels may rise in response to macrolide antibiotics. Clarithromycin and cabergoline may interact; detailed information is available in the relevant monograph. Exceptions: Nicergoline, Pergolide, and Cabergoline.
Estazolam	Estazolam's serum levels may rise in response to macrolide antibiotics. Management: Take into account a less likely to interact option. Azithromycin is most likely a lower-risk macrolide, while benzodiazepines (such as lorazepam and oxazepam) that are less dependent on CYP3A metabolism are also less likely to interact.
Everolimus	CYP3A4 Inhibitors (Moderate) may raise the level of Everolimus in the blood. For the majority of cases, everolimus dose decreases are necessary. For detailed dose modification and monitoring suggestions, consult the full monograph or prescription information.
Everolimus	CYP3A4 (Moderate) and P-glycoprotein inhibitors may raise the level of Everolimus in the blood. For the majority of cases, everolimus dose decreases are necessary.
FentaNYL	The serum levels of FentaNYL may rise in response to CYP3A4 Inhibitors (Moderate). Management: After starting this combination, keep a watchful eye on the patients for a few days and alter the fentanyl dosage as necessary.
GuanFACINE	CYP3A4 Inhibitors (Moderate) may raise the level of GuanFACINE in the serum. When starting this combo, cut the guanfacine dose in half.
Ibrutinib	Ibrutinib's serum levels may rise when taken with CYP3A4 Inhibitors (Moderate). Treatment: While paired with mild CYP3A4 inhibitors, reduce ibrutinib dosage to 280 mg per day when treating B-cell malignancies. When treating graft versus host disease, keep a close eye on the patients and adjust the ibrutinib dosage as necessary based on side effects.
Ivacaftor	Ivacaftor's serum levels may rise when taken with CYP3A4 Inhibitors (Moderate). Management: Ivacaftor dosage reductions are necessary; for complete monograph material and specific recommendations based on age and weight. No dosage modification
Ivosidenib	Possibly amplifies the QTc-prolonging effects of moderate CYP3A4 inhibitors (Moderate Risk). Ivosidenib's serum levels may rise in response to moderate CYP3A4 inhibitors that extend the QT interval (Moderate Risk). Management: Take into account different pharmacological combinations. If combined, keep an eye out for cardiac arrhythmias and a prolonged QTc interval. Patients may be considerably more at risk for QTc prolongation if they have additional risk factors.
Lorlatinib	May lower the serum level of CYP3A4 substrates (High risk with Inducers). Management: Avoid taking lorlatinib at the same time as any CYP3A4 substrates for which even a small drop in serum levels of the substrate could result in therapeutic failure and negative clinical outcomes.
Lurasidone	Lurasidone's serum levels may rise in response to moderate CYP3A4 inhibitors. Treatment: According to the US labelling for lurasidone, the dose should be cut in half and used with a mild CYP3A4 inhibitor. Some non-US labelling advises starting with 20 mg/day of lurasidone and limiting the dosage to 40 mg/day; concurrent use of grapefruit products should be avoided.
Methadone	Possibly amplifies the QTc-prolonging effects of moderate CYP3A4 inhibitors (Moderate Risk). The blood concentration of methadone may rise in response to moderate CYP3A4 inhibitors with QT prolongation (moderate risk). Management: Take into account different pharmacological combinations. If combined, keep an eye out for cardiac arrhythmias and a prolonged QTc interval. Patients may be considerably more at risk for QTc prolongation if they have additional risk factors.
Midazolam	Midazolam's serum levels may rise in response to macrolide antibiotics. Management: Take into account a less likely to interact option. Azithromycin is most likely a lower-risk macrolide, while benzodiazepines (such as lorazepam and oxazepam) that are less dependent on CYP3A metabolism are also less likely to interact.
Mitotane	May lower the serum level of CYP3A4 substrates (High risk with Inducers). Treatment: When administered in individuals receiving mitotane, doses of CYP3A4 substrates may need to be significantly modified.
Olaparib	Olaparib's serum levels may rise when taken with CYP3A4 Inhibitors (Moderate). Management: If at all feasible, refrain from administering mild CYP3A4 inhibitors to patients receiving olaparib. Olaparib dosage should be decreased to 150 mg twice daily if such concomitant use cannot be avoided.
Pitavastatin	The serum levels of Pitavastatin may rise when Erythromycin (Systemic) is used. Management: When used in conjunction with erythromycin, pitavastatin dosage should be kept to a maximum of 1 mg/day (adult dose). Monitor patients more closely for signs of pitavastatin toxicity if this combination is taken.
Pitolisant	May lower the serum level of CYP3A4 substrates (High risk with Inducers). Management: Pitolisant should not be used in conjunction with a CYP3A4 substrate that has a limited therapeutic index. When administered with pitolisant, other CYP3A4 substrates need to be checked more carefully.
QT-prolonging Class IA Antiarrhythmics (Highest Risk)	May increase erythromycin's ability to extend QTc (Systemic). Erythromycin (Systemic) may increase the effect of Class IA antiarrhythmics that prolong QT by increasing QTc (Highest Risk). The serum concentration of QT-prolonging Class IA Antiarrhythmics may be increased by systemic erythromycin (Highest Risk). Management: Take into account different pharmacological combinations.
QT-prolonging Kinase Inhibitors (Highest Risk)	May increase the effect of moderate CYP3A4 inhibitors on QTc prolongation (Moderate Risk). The serum concentration of QT-prolonging Kinase Inhibitors may rise in response to QT-prolonging Moderate CYP3A4 Inhibitors (Moderate Risk) (Highest Risk). Management: Take into account different pharmacological combinations. If combined, keep an eye out for cardiac arrhythmias and a prolonged QTc interval. Patients may be considerably more at risk for QTc prolongation if they have additional risk factors. Exceptions: Ivosidenib.
QT-prolonging Miscellaneous Agents (Highest Risk)	The QTc-prolonging action of QT-prolonging Miscellaneous Agents may be enhanced by QT-prolonging Moderate CYP3A4 Inhibitors (Moderate Risk) (Highest Risk). QT-prolonging Miscellaneous Agents' serum concentration may be increased by QT-prolonging Moderate CYP3A4 Inhibitors (Moderate Risk) (Highest Risk). Management: Take into account different pharmacological combinations. If combined, keep an eye out for cardiac arrhythmias and a prolonged QTc interval. Patients who have other QTc prolongation risk factors may be significantly more at risk.
Ranolazine	Ranolazine's serum levels may rise after taking CYP3A4 Inhibitors (Moderate). Treatment: In patients receiving mild CYP3A4 inhibitors concurrently, the adult ranolazine dose should be restricted to no more than 500 mg twice daily (e.g., diltiazem, verapamil, erythromycin, etc.).
Rifamycin Derivatives	The metabolism of derivatives of rifamycin may be slowed down by macrolide antibiotics. Rifapentine is an exception.
Rilpivirine	The serum levels of Rilpivirine may rise in response to macrolide antibiotics. Management: To prevent this potential interaction, take into account using azithromycin or another non-macrolide alternative when necessary.
Rivaroxaban	Rivaroxaban's serum levels may rise in response to systemic erythromycin. Management: Erythromycin should not be used in patients with compromised renal function unless the possible benefits outweigh the potential dangers. In patients with normal renal function, this combination is unlikely to have any clinically relevant effects.
Sildenafil	The serum concentration of Sildenafil may rise when Erythromycin (Systemic) is used. Management: The US label for pulmonary arterial hypertension recommends no dose change, but the Canadian label suggests lowering the dosage to 20 mg twice per day. Consider utilising a lower initial dose of 25 mg for erectile dysfunction in patients who are already taking erythromycin.
Sincalide	The therapeutic benefit of Sincalide may be reduced by medications that affect gallbladder function. Prior to using sincalide to induce gallbladder contraction, you should think about stopping any medications that can impair gallbladder motility. The serum levels of Sirolimus may rise when Erythromycin (Systemic) is used.
Sirolimus	Erythromycin serum levels may rise in response to sirolimus (Systemic). Management: If sirolimus is taken with erythromycin, keep an eye out for elevated serum concentrations. Lower starting dosages of sirolimus or dose reductions of sirolimus will probably be needed.
Sodium Picosulfate	Antibiotics may reduce Sodium Picosulfate's therapeutic impact. Management: If a patient previously used or is currently using an antibiotic, think about utilising an alternative product for bowel cleansing prior to a colonoscopy.
Sonidegib	Sonidegib's serum levels may rise when taken with CYP3A4 Inhibitors (Moderate). Management: Whenever possible, refrain from taking moderate CYP3A4 inhibitors and sonidegib concurrently. Limit the use of CYP3A4 inhibitors to less than 14 days when concurrent usage cannot be avoided, and keep an eye out for sonidegib toxicity (particularly musculoskeletal adverse reactions).
St John's Wort	May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Management: Consider an alternative for one of the interacting drugs. Some combinations may be specifically contraindicated. Consult appropriate manufacturer labeling.
Suvorexant	Suvorexant's serum levels may rise when taken with CYP3A4 Inhibitors (Moderate). Treatment: Suvorexant is administered at a dose of 5 mg per day to patients who are on a mild CYP3A4 inhibitor. If more dosage is required for effectiveness, the maximum amount per day is 10 mg.
Tezacaftor	Tezacaftor's serum levels may rise when taken with CYP3A4 Inhibitors (Moderate). Treatment: Tezacaftor/ivacaftor (100 mg/150 mg) should be administered in the morning, every other day, when taken with mild CYP3A4 inhibitors. Every other day, in the morning, on the days that tezacaftor and ivacaftor are given alternately, ivacaftor (150 mg) alone should be administered.
Theophylline Derivatives	Theophylline derivatives' metabolism may be slowed down by macrolide antibiotics. Exceptions: Dyphylline.
Tolvaptan	Tolvaptan's serum levels may rise in response to CYP3A4 Inhibitors (Moderate). Management: When used with a mild CYP3A4 inhibitor, jynarque dosage must be adjusted. For more detailed advice, consult the complete interaction monograph or labelling. Samsca use should generally be avoided when moderate CYP3A4 inhibitors are present.
Triazolam	The systemic form of erythromycin (Systemic) may raise the serum level of triazolam. Management: Look into alternatives to using erythromycin and triazolam together. If coupled, exercise greater caution and keep a closer eye out for adverse effects of triazolam. Triazolam dosage reductions can be required.
Typhoid Vaccine	The Typhoid Vaccine's therapeutic benefits may be reduced by antibiotics. The only strain impacted is the live attenuated Ty21a strain. Treatment: Patients receiving systemic antibacterial drugs should refrain from receiving the live attenuated typhoid vaccination (Ty21a). It is recommended to wait at least 3 days following the last dose of antibacterial medication before administering this vaccine.
Vardenafil	The serum levels of Vardenafil may rise when Erythromycin (Systemic) is used. Treatment: Use erythromycin concurrently with vardenafil film-coated tablets (Levitra) at a dose of no more than 5 mg per 24 hours. Using vardenafil orally disintegrating pills concurrently
Venetoclax	Venetoclax's serum levels may rise in response to moderate CYP3A4 inhibitors. Management: In patients who need these combinations, lower the dose of venetoclax by at least 50%.
Venetoclax	Venetoclax serum levels may rise in response to P-glycoprotein/ABCB1 inhibitors. In patients who need concurrent treatment with P-glycoprotein (P-gp) inhibitors, consider reducing the dose of venetoclax by at least 50%.
Zopiclone	Zopiclone's serum levels may rise when taken with CYP3A4 Inhibitors (Moderate). Management: If taken with a mild CYP3A4 inhibitor, the first adult dose of zopiclone shouldn't be more than 3.75 mg. If these medications are taken together, patients should be kept an eye out for any zopiclone toxicity symptoms.
Risk Factor X (Avoid combination)
Amiodarone	May increase erythromycin's ability to extend QTc (Systemic). Amiodarone's ability to extend QTc may be enhanced by the systemic antibiotic erythromycin.
Aprepitant	Amiodarone's serum levels may rise in response to systemic erythromycin.
Asunaprevir	Aprepitant's serum levels may rise in response to moderate CYP3A4 inhibitors.
Barnidipine	Asunaprevir's serum levels may rise in response to moderate CYP3A4 inhibitor therapy.
BCG (Intravesical)	The serum levels of Barnidipine may rise in response to erythromycin (Systemic).
Bosutinib	Bosutinib's serum levels may rise when taken with CYP3A4 Inhibitors (Moderate).
Budesonide (Systemic)	The serum concentration of Budesonide may rise while using moderate amounts of CYP3A4 inhibitors (Systemic).
Cholera Vaccine	The therapeutic benefit of the cholera vaccine may be reduced by antibiotic use. Management: Cholera vaccine should not be administered to individuals taking systemic antibiotics or within 14 days after taking oral or parenteral antibiotics.
Clindamycin (Topical)	The therapeutic impact of Clindamycin may be diminished by systemic erythromycin (Topical).
Cobimetinib	Cobimetinib's serum levels may rise when taken with CYP3A4 Inhibitors (Moderate). Management: Steer clear of combining cobimetinib with mild CYP3A4 inhibitors. Reduce the dosage of cobimetinib to 20 mg per day if concomitant short-term (14 days or less) use cannot be avoided.
Domperidone	Possibly amplifies the QTc-prolonging effects of moderate CYP3A4 inhibitors (Moderate Risk). The blood concentration of Domperidone may rise in response to moderate CYP3A4 inhibitors that extend the QT interval (Moderate Risk).
Dronedarone	May increase erythromycin's ability to extend QTc (Systemic). The systemic form of erythromycin may raise the serum level of dronedarone.
Flibanserin	Flibanserin's serum levels may rise in response to moderate CYP3A4 inhibitors.
Fluconazole	May increase erythromycin's ability to extend QTc (Systemic). Fluconazole may raise the level of erythromycin in the serum (Systemic).
Fosaprepitant	Fosaprepitant's serum levels may rise when taken with CYP3A4 Inhibitors (Moderate).
Ivabradine	Ivabradine's serum levels may rise in response to moderate CYP3A4 inhibitors.
Lincomycin	Lincomycin's therapeutic impact may be diminished by erythromycin (Systemic).
Lomitapide	Lomitapide's serum levels may rise when taken with CYP3A4 Inhibitors (Moderate).
Lovastatin	The serum levels of Lovastatin may rise when Erythromycin (Systemic) is used.
Mequitazine	The arrhythmogenic effect of mequitazine may be enhanced by erythromycin (Systemic). Treatment: It is not advised to administer mequitazine and erythromycin at the same time.
Mizolastine	The serum levels of Mizolastine may rise in response to macrolide antibiotics.
Naloxegol	Naloxegol's serum levels may rise in response to moderately potent CYP3A4 inhibitors.
Neratinib	Neratinib's serum levels may rise in response to moderate CYP3A4 inhibitors.
PAZOPanib	P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of PAZOPanib.
Pimozide	CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Pimozide.
Pimozide	May enhance the QTc-prolonging effect of QT-prolonging Agents (Moderate Risk).
QT-prolonging Class III Antiarrhythmics (Highest Risk)	May increase erythromycin's ability to extend QTc (Systemic). Systemic erythromycin may increase the effect of QT-prolonging Class III antiarrhythmics (Highest Risk). The serum concentration of QT-prolonging Class III Antiarrhythmics
QuiNIDine	Erythromycin (Systemic) may enhance the QTc-prolonging effect of QuiNIDine. Erythromycin (Systemic) may increase the serum concentration of QuiNIDine.
Saquinavir	Erythromycin (Systemic) may enhance the QTc-prolonging effect of Saquinavir. Erythromycin (Systemic) may increase the serum concentration of Saquinavir. May be increased by systemic erythromycin (Highest Risk). Management: According to the dronedarone US prescription instructions and a separate interaction monograph, using erythromycin in combination with dronedarone is not recommended. Dronedarone is an example.
Simeprevir	The serum levels of Simeprevir may rise in response to erythromycin (Systemic). Simeprevir may raise Erythromycin's serum levels (Systemic).
Simvastatin	The serum levels of Simvastatin may rise when Erythromycin (Systemic) is used.
Topotecan	The serum concentration of topotecan may rise in response to P-glycoprotein/ABCB1 inhibitors.
Ulipristal	CYP3A4 Inhibitors (Moderate) may increase the serum concentration of Ulipristal. Management: This is specific for when ulipristal is being used for signs/symptoms of uterine fibroids (Canadian indication). When ulipristal is used as an emergency contraceptive, patients receiving this combination should be monitored for ulipristal toxicity.
VinCRIStine (Liposomal)	P-glycoprotein/ABCB1 Inhibitors may increase the serum concentration of VinCRIStine (Liposomal).

Monitoring Parameters:

Monitor the response to therapy, QTc Interval (especially in patients at high risk), liver function tests.

How to administer Erythromycin?

Oral:

• Two hours before or after a meal, provide base, PCE, or stearate dose forms on an empty stomach.
  without respect to meals, provide ethylsuccinate (EES) or delayed-release (ERY-TAB); To alleviate GI pain, it can be given after eating.
• Do not chew or break enteric-coated tablets or delayed-release capsules; instead, swallow them whole.

IV:

• 1 g should be infused for 20–60 minutes.
• The vein may become quite irritated during IV infusion; the infusion should be slow enough to reduce discomfort along the vein.
• Give no IV pushes or boluses.

Mechanism of action of Erythromycin:

Blocks the chain elongation stage of RNA-dependent protein synthesis; by binding to the 50S ribosomal unit, it prevents transpeptidation.

Absorption:

• Oral: 18 to 45 percent; variable, but more efficient with salt forms than base forms; ethylsuccinate might be more readily absorbed when consumed with food.

Distribution:

• • Even when there is inflammation, there is low relative blood diffusion into the CSF.
    CSF:
  • Ratio of blood levels meninges 2% to 13% normal 7% to 25% of meninges are inflamed.

Protein binding:

• Base: 73 percent to 81 percent.

Metabolism:

• Demethylation primarily via hepatic CYP3A4.

Half-life elimination:

• Neonates (≤15 days of age): 2.1 hours;
• Adults: Peak: 1.5-2 hours;
• End-stage renal disease: 5-6 hours

Time to peak serum concentration:

• Base: 4 hours;
• Ethylsuccinate: 0.5-2.5 hours;
• Stearate: 3 hours;
• delayed with food due to differences in absorption

Excretion:

• Primarily feces;
• urine (2 percent  to 15 percent  as unchanged drug)

International Brands of Erythromycin:

• E.S. 400
• EES 600
• Erybid
• Eryc
• Erythro-Base
• Erythro-ES
• Erythro-S
• Erythrocin
• NOVO-Rythro
• Estolate
• NOVO-Rythro
• Ethylsuccinate
• PCE
• Abboticin
• E.S. Granules
• Ery-Tab
• EryPed 200
• EryPed 400
• Erythrocin Lactobionate
• Erythrocin Stearate
• PCE
• EES 200
• Abomacetin
• Ai Jia Xing
• Aldricin
• Ambamida
• Ao Shu Xin
• Baknyl
• Dothrocyn
• E-Mycin
• Ecolide
• EES
• Elthrocin
• Emu-V E
• ERA
• Erase
• Eribiotic
• Erigran
• Erios
• Eritrex
• Eritrocina
• Ery
• Ery Max
• Ery-Tab
• Eryc
• Erycin
• Erycip
• Eryest
• Eryko
• Erymax
• Erymer
• Erymycin AF
• Eryped 200
• Eryped 400
• Erysanbe
• Erytab-S
• Eryth-Mycin
• Erythin
• Erythran
• Erythrin
• Erythro
• Erythro-Teva
• Erythrocid
• Erythrocin
• Erythrocine
• Erythrodar
• Erythromil
• Erythromycin
• Erythromycinum
• Erythropen
• Etocin
• Etrocin
• Etrotab
• Farmicina
• Firmac
• Hexabiotin
• Ilosone
• Indo-250
• Narlecin
• Eritrolag
• Eritromicin
• Eritromicina
• Ermycin
• ERO-125
• Erocin
• Eromel
• Eromycin
• Erotab
• Omathrocin
• Panamicyn
• Pantomicina
• Pharothrocin
• Primacine
• Razimycin
• Retorin Suspension
• Rhythm
• Roug-mycin
• Rubimycin
• Ryebact
• Rythocin
• Rythrocaps
• Trovilon
• Xin Hong Kang

Erythromycin Brand Names in Pakistan:

Erythromycin Injection 1 G in Pakistan
Erythrocin	Indus Pharma (Pvt) Ltd.

Erythromycin Drops 100 Mg in Pakistan
Erythrocin	Indus Pharma (Pvt) Ltd.

Erythromycin Drops 100 Mg/2.5ml in Pakistan
Emycin	Lisko Pakistan (Pvt) Ltd
Irzacin	Irza Pharma (Pvt) Ltd.

Erythromycin Suspension 200 Mg in Pakistan
Erythrocin	Indus Pharma (Pvt) Ltd.

Erythromycin Suspension 125 Mg/5ml in Pakistan
Epthrocin	Epoch Pharmaceutical
Erthromed	Mediate Pharmaceuticals (Pvt) Ltd
Erysin	Swiss Pharmaceuticals (Pvt) Ltd.
Erythromycin	Munawar Pharma (Pvt) Ltd.
Irzacin	Irza Pharma (Pvt) Ltd.
Novomycin	Krka-Pak Pharmaceutical & Chemical Works
Tethrocin	Tabros Pharma

Erythromycin Suspension 200 Mg/5ml in Pakistan
Acumen	Rakaposhi Pharmaceutical (Pvt) Ltd.
D Mycin	Don Valley Pharmaceuticals (Pvt) Ltd.
Deltacin	Delta Pharma (Pvt) Ltd.
Emycin	Lisko Pakistan (Pvt) Ltd
Erithrin	Ferozsons Laboratoies Ltd.
Erthromed	Mediate Pharmaceuticals (Pvt) Ltd
Erycare Es	Csh Pharmaceuticals-North (Pvt) Ltd
Erymac	Bio Labs (Pvt) Ltd.
Erymox	Mediceena Pharma (Pvt) Ltd.
Erythromycin	Don Valley Pharmaceuticals (Pvt) Ltd.
Erythromycin	Shifa Laboratories.(Pvt) Ltd.
Erywil	Wilsons Pharmaceuticals
Geoerythcin	Geofman Pharmaceuticals
Lolvan	Nimrall Laboratories
Muzomycin	Alkemy Pharmaceutical Laboratories (Private) Ltd.
Mycin-E	Polyfine Chempharma (Pvt) Ltd.
Ocemycin	Safe Pharmaceutical (Pvt) Ltd.
Trocin	Karachi Pharmaceutical Laboratory
Xexab	Everest Pharmaceuticals

 

Erythromycin Suspension 250 Mg/5ml in Pakistan
Erythromycin	Pliva Pakistan (Pvt) Limited
Novomycin	Krka-Pak Pharmaceutical & Chemical Works

 

Erythromycin Suspension 500 Mg/5ml in Pakistan
Xyrox-E	Jawa Pharmaceuticals (Pvt) Ltd.

 

Erythromycin Solution 2 %W/V in Pakistan
Eryderm	Indus Pharma (Pvt) Ltd.

 

Erythromycin Solution 4 %W/V in Pakistan
Stiemycin-Ds	Glaxosmithkline

 

Erythromycin Granules 200 Mg/5ml in Pakistan
Erythin	Webros Pharmaceuticals

 

Erythromycin Gel 2 %W/W in Pakistan
Cosmun Plus	Festel Lab
Isocane	Neophar Health-Care

 

Erythromycin Lotion 1.5 %W/V in Pakistan
Akne Ban-T	Wilshire Laboratories (Pvt) Ltd.

 

Erythromycin Tablets 250 Mg in Pakistan
Acumen	Rakaposhi Pharmaceutical (Pvt) Ltd.
D Mycin	Don Valley Pharmaceuticals (Pvt) Ltd.
Deltacin	Delta Pharma (Pvt) Ltd.
Ecin	Efroze Chemical Industries (Pvt) Ltd.
Emycin	Lisko Pakistan (Pvt) Ltd
Epthrocin	Epoch Pharmaceutical
Erithrin	Ferozsons Laboratoies Ltd.
Erupcin	Fynk Pharmaceuticals
Erycina	Medipak Limited
Erymin	Bloom Pharmaceuticals (Pvt) Ltd.
Erymox	Mediceena Pharma (Pvt) Ltd.
Erytab	Hamaz Pharmaceutical (Pvt) Ltd.
Erythin	Webros Pharmaceuticals
Erythro	Unexo Labs (Pvt) Ltd.
Erythro	Unexo Labs (Pvt) Ltd.
Erythrocin	Indus Pharma (Pvt) Ltd.
Erythrocin	Indus Pharma (Pvt) Ltd.
Erythromycin	Dosaco Laboratories
Erythromycin	Munawar Pharma (Pvt) Ltd.
Erythromycin	Irza Pharma (Pvt) Ltd.
Erythromycin	Don Valley Pharmaceuticals (Pvt) Ltd.
Erythromycin	Pliva Pakistan (Pvt) Limited
Erythromycin	Safina Pharma (Pvt) Ltd
Erythrosaf	Saaaf Pharmaceuticals
Erywil	Wilsons Pharmaceuticals
Geoerythcin	Geofman Pharmaceuticals
Infectocin	Euro Pharma International
Irzacin	Irza Pharma (Pvt) Ltd.
Mb-Throcin	Multinational Buisness Link
Medrithro	Medera Pharmaceuticals (Pvt) Ltd.
Muconil	Pearl Pharmaceuticals
Novomycin	Krka-Pak Pharmaceutical & Chemical Works
Ocemycin	Safe Pharmaceutical (Pvt) Ltd.
Rythobact	Caylex Pharmaceuticals (Pvt) Ltd.
Thromycin	Semos Pharmaceuticals (Pvt) Ltd.
Tiloryth	Glitz Pharma
Trocin	Karachi Pharmaceutical Laboratory
Wilmycin	Wilshire Laboratories (Pvt) Ltd.
Wilmycin	Wilshire Laboratories (Pvt) Ltd.
Xexab	Everest Pharmaceuticals

 

Erythromycin Tablets 500 Mg in Pakistan
Acumen	Rakaposhi Pharmaceutical (Pvt) Ltd.
D Mycin	Don Valley Pharmaceuticals (Pvt) Ltd.
Deltacin	Delta Pharma (Pvt) Ltd.
Emycin	Lisko Pakistan (Pvt) Ltd
Erithrin	Ferozsons Laboratoies Ltd.
Erupcin	Fynk Pharmaceuticals
Erycare	Csh Pharmaceuticals-North (Pvt) Ltd
Erycina	Medipak Limited
Erymox	Mediceena Pharma (Pvt) Ltd.
Erytab	Hamaz Pharmaceutical (Pvt) Ltd.
Erytab	Hamaz Pharmaceutical (Pvt) Ltd.
Erythin	Webros Pharmaceuticals
Erythro	Unexo Labs (Pvt) Ltd.
Erythro	Unexo Labs (Pvt) Ltd.
Erythrocin	Indus Pharma (Pvt) Ltd.
Erythromycin	Don Valley Pharmaceuticals (Pvt) Ltd.
Erythromycin	Safina Pharma (Pvt) Ltd
Erythrosaf	Saaaf Pharmaceuticals
Geoerythcin	Geofman Pharmaceuticals
Mb Throcin	Multinational Buisness Link
Medrithro	Medera Pharmaceuticals (Pvt) Ltd.
Novomycin	Krka-Pak Pharmaceutical & Chemical Works
Rythobact	Caylex Pharmaceuticals (Pvt) Ltd.
Throgin	Jinnah Pharmaceuticals
Tiloryth	Glitz Pharma
Wilmycin	Wilshire Laboratories (Pvt) Ltd.
Wilmycin	Wilshire Laboratories (Pvt) Ltd.
Xexab	Everest Pharmaceuticals

 

Erythromycin Tablets 250 Mg/5ml in Pakistan
Xyrox	Jawa Pharmaceuticals(Pvt) Ltd.

 

Erythromycin Tablets 500 Mg/5ml in Pakistan
Xyrox	Jawa Pharmaceuticals(Pvt) Ltd.

 

Erythromycin Capsules 250 Mg in Pakistan
Erythromycin	Lahore Chemical & Pharmaceutical Works (Pvt) Ltd

 

Erythromycin Powder 200 Mg in Pakistan
Erycin-20%	Univet Pharmaceuticals