Famotidine (Pepcid) is an antihistamine that inhibits the H-2 histamine receptors in the stomach inhibiting acid secretion. It is used in the treatment and prevention of heartburn and peptic ulcer disease.

Famotidine Uses:

• Oral:

  • Gastroesophageal reflux disease:

    • Treatment of gastroesophageal reflux disease (GERD) and esophagitis secondary to GERD.

  • Heartburn (OTC only):

    • heartburn, acid indigestion, and sour stomach.

  • Peptic ulcer disease:

    • Treatment of active duodenal or gastric ulcers.

Note: Even though a labeled indication, proton pump inhibitors (PPIs) are considered the standard of care for treatment of peptic ulcer disease (PUD) rather than H-2-receptor antagonists (eg, famotidine) (Lanas 2017; Vakil 2019).

• Injection:

  • Patients not able to take oral medication:

    • For patients who cannot take orally

  • Off-Label Use of Famotidine in Adults:

    • Aspiration prophylaxis in patients undergoing anesthesia
    • Chronic spontaneous urticaria
    • Infusion reaction, premedication
    • Mastocytosis
    • Stress ulcer prophylaxis in select critically ill patients

Famotidine (Pepcid) Dose in Adults

Famotidine (Pepcid) Dose in the Aspiration prophylaxis in patients undergoing anesthesia (off-label):

Note: can be used in patients high risk for aspiration:

• IV: 20 mg as a single dose ~40 to 60 minutes before inducing anesthesia;
• It can be combined with rapid-acting nonparticulate antacid (eg, oral sodium citrate and citric acid) and/or metoclopramide.

Famotidine (Pepcid) Dose in the treatment of chronic spontaneous urticaria as an alternative agent (adjunct) (off-label):

Note: Used as an adjunct if poor response to full-dose H-1 antihistamine.

• Oral: 20 mg twice daily combined with H-1 antihistamine;
• Wait for 2 to 4 weeks to measure the appropriate response.

Famotidine (Pepcid) Dose in the treatment of Gastroesophageal reflux disease:

• Initial therapy:

  • Mild and intermittent symptoms (<2 episodes/week), and no evidence of erosive esophagitis:

Note: For much serious or recurring initial symptoms, with or without proof of erosive esophagitis, a proton pump inhibitor (PPI) as initial therapy is recommended.

• Oral: 10 mg twice daily as needed; if symptoms persist after 2 to 4 weeks, increase to 20 mg twice daily for 2 weeks; if symptoms improve, may continue therapy as needed.

Note: If symptoms persist after 2 weeks of 20 mg twice daily, discontinue and consider PPI therapy.

Famotidine (Pepcid) Dose in the treatment of Residual acid reflux symptoms despite maximal PPI therapy (adjunct):

• Oral: 20 mg one time each day given before sleep in addition to PPI therapy.
• The dose may also be administered intermittently or on-demand with scheduled PPI.

• OTC labeling (patient-guided therapy):

  • Heartburn, mild intermittent symptoms: Oral: 10 to 20 mg up to two times a day when needed (maximum: 40 mg/day); may also be taken 10 to 60 minutes before meals or drinks that initiate heartburn (maximum: 40 mg/day).

Famotidine (Pepcid) Dose for premedication in Infusion reactions (adjunct) (off-label):

• IV, Oral: 20 mg usually administered 30 to 60 minutes prior to infusion of certain chemotherapy agents or biologics;
• It is mostly given in combination with an H-1 antihistamine (eg, diphenhydramine) and glucocorticoid (refer to institutional protocols).

Famotidine (Pepcid) Dose in the treatment of Mastocytosis (adjunct):

• Oral: 10 to 20 mg every 12 hours modified to attain GI symptom relief.
• Typically consumed with other appropriate agents (eg, H-1 antihistamine and/or leukotriene inhibitor).

Famotidine (Pepcid) Dose for Stress ulcer prophylaxis in selected critically ill patients:

Note: For ICU patients with linked risk factors for GI bleeding (including coagulopathy, mechanical ventilation for >48 hours, traumatic brain injury, history of GI ulceration or bleeding within the past year, extensive burns); suspend prophylaxis when the risk factors are resolved.

• Oral or via nasogastric (NG) tube (alternative to enteral PPI):
  • 20 mg twice a day.
• IV:
  • 20 mg twice a day.

Famotidine (Pepcid) Dose in Childrens

Famotidine (Pepcid) Dose in the treatment of GERD:

• Oral:

  • Suspension:

    • Infants <3 months:
      • 0.5 mg/kg/dose one time each day for up to 8 weeks;
      • If not effective after 2 weeks, increase the dose to 1 mg/kg/dose one time a day is suggested.
    • Infants ≥3 months, Children, and Adolescents ≤16 years:
      • Initial: 0.5 mg/kg/dose two times a day;
      • The maximum dose is 40 mg/dose;
      • Doses up to 1 mg/kg/dose two times a day have been reported.

  • Tablets:

    • Children and Adolescents ≥40 kg:
      • 20 mg twice a day for up to 6 weeks;
      • For esophagitis and additional symptoms due to GERD, may use 20 to 40 mg twice a day for up to 12 weeks

• IV:

  • Infants <3 months:
    • 0.25 mg/kg/dose once each day;
    • The dose based on a pharmacokinetic study that included 7 patients <3 months who were given IV famotidine.
  • Infants ≥3 months:
    •  Initial: 0.25 mg/kg/dose every 12 hours;
    • The maximum dose is 20 mg/dose;
    • The dose is based on a pharmacokinetic study that included 11 patients >3 to 12 months who received IV famotidine.
  • Children and Adolescents:
    • Initial: 0.25 mg/kg/dose every 12 hours;
    • The maximum dose: 20 mg/dose;
    • Doses up to 0.5 mg/kg/dose every 12 hours have been reported

Famotidine (Pepcid) Dose in the treatment of Heartburn, acid indigestion, or sour stomach (OTC labeling):

• Children ≥12 years and Adolescents:

  • Oral: 10 to 20 mg after every 12 hours;
  • The dose can be taken 15 to 60 minutes before eating food that causes heartburn;
  • The maximum daily dose is 2 tablets/day (20 to 40 mg dependent upon OTC product)

Famotidine (Pepcid) Dose in the treatment of pathological hypersecretory conditions (eg, Zollinger-Ellison):

• Adolescents ≥17 years:

  • Oral: Initial: 20 mg every 6 hours, may increase up to 160 mg every 6 hours
  • IV: 20 mg every 12 hours

Famotidine (Pepcid) Dose in the treatment of Peptic ulcer disease:

• Oral:

  • Suspension: Children and Adolescents ≤16 years:
    • 0.5 mg/kg/day before sleeping or divided twice each day;
    • The maximum daily dose is 40 mg/day;
    • Doses up to 1 mg/kg/day at bedtime or distributed twice daily have been consumed.

• Tablets:

  • Children and Adolescents >40 kg:

    • Duodenal ulcer: Acute therapy: 40 mg once a day before sleep or 20 mg two times daily for 4 to 8 weeks
    • Gastric ulcer: Acute therapy: 40 mg once a day at bedtime for up to 8 weeks

• IV:

  • Children and Adolescents:
    • Initial: 0.25 mg/kg/dose every 12 hours;
    • The maximum dose: 20 mg/dose;
    • Doses up to 0.5 mg/kg/dose every 12 hours is reported

Famotidine (Pepcid) Dose for the prophylaxis of stress ulcers, gastric acid suppression:

• Infants, Children, and Adolescents:

  • IV: 1 to 2 mg/kg/day in divided doses every 8 to 12 hours;
  • The maximum daily dose is 40 mg/day.

Famotidine Pregnancy Risk Category: B

• Famotidine passes the placental barrier.
• The renal clearance of famotidine may be affected by pregnancy-related physiological changes.
• Histamine H antagonists were evaluated for the treatment and prevention of gastroesophageal acid disease (GERD), in pregnancy.
• For initial therapy, agents other than famotidine might be preferred.
• For aspiration prophylaxis, you can take histamine H antagonists before a cesarean birth.

Famotidine use during breastfeeding:

• Breast milk contains Famotidine.
• When famotidine was compared to a therapeutic infant dose of 0.5 mg/kg/day, the relative infant dose (RID), of 2.2% was determined. This is based on the peak breastmilk concentration.
• When the RID of the medication is less than 10%, breastfeeding can be considered satisfactory.
• The RID of Famotidine was determined using a milk content of 0.072 mg/mL. This gives an estimated daily infant dose via breastmilk of 0.011 mg/kg/day.
• The mother administered a single dose orally of 40 mg famotidine to her milk.
• According to the manufacturer breastfeeding should be considered during therapy.
• One must consider the risks of infant exposure as well as the benefits to the mother from breastfeeding.
• Famotidine is a preferred agent when treatment with a histamine H antagonist must be done. This is due to the lower concentrations of famotidine in breast milk.

Famotidine (Pepcid) Dose in Kidney Disease:

• Injection:

  • CrCl ≥50 mL/minute: No dosage adjustment required.
  • CrCl <50 mL/minute: Administer 50% of dose or increase the interval to every 36 to 48 hours.

• Oral:

  • Active duodenal ulcer:

    • CrCl 30 to 60 mL/minute: Maximum dose: 20 mg one time daily or 40 mg every other day.
    • CrCl <30 mL/minute: Maximum dose: 20 mg on alternate day or 10 mg once a day.

  • Maintenance of duodenal ulcer:

    • CrCl 30 to 60 mL/minute: Maximum dose: 20 mg on alternate day or 10 mg once daily
    • CrCl <30 mL/minute: Maximum dose: 10 mg every other day

  • Gastric ulcer:

    • CrCl 30 to 60 mL/minute: Maximum dose: 20 mg once each day or 40 mg on alternate day
    • CrCl <30 mL/minute: Maximum dose: 20 mg every other day or 10 mg once daily

  • GERD:

    • Esophagitis and accompanying symptoms due to GERD:
      • CrCl 30 to 60 mL/minute:
        • The maximum dose for the 20 mg twice-daily regimen: 20 mg once daily or 40 mg every alternate day
        • The maximum dose for the 40 mg twice-daily regimen: 40 mg once every day
      • CrCl <30 mL/minute:
        • The maximum dose for the 20 mg twice-daily regimen: 20 mg every other day or 10 mg once a day
        • The maximum dose for the 40 mg two times in daily routine: 20 mg one time a day
    • Treatment of GERD (short-term):
      • • CrCl 30 to 60 mL/minute: Maximum dose: 20 mg one time a day
        • CrCl <30 mL/minute: Maximum dose: 20 mg on alternate day or 10 mg once a day
    • Pathological hypersecretory conditions: Avoid use

Dose in Liver Disease:

There are no dosage adjustments given in the manufacturer's labeling.

All reported adverse drug reactions are for the oral formulations unless otherwise noted.

Common Side Effects of Famotidine (Pepcid):

• Central nervous system:

  • Agitation

Less Common Side Effects of Famotidine (Pepcid):

• Central nervous system:

  • Headache
  • Dizziness

• Gastrointestinal:

  • Diarrhea
  • Constipation
  • Necrotizing enterocolitis

• Local:

  • Irritation at the injection site

Contraindications to Famotidine Include:

Severe hypersensitivity (eg anaphylaxis), to famotidine or other H-2 antagonists or any component of this formulation.

OTC labeling

• Use OTC for self-medication. Do not use OTC if you experience difficulty or pain while ingesting food, nausea, vomiting, bloody or black stool.
• Other acid reducers may cause allergic reactions
• Renal impairment
• Coadministration with acid reducers

Warnings and precautions

• ECG changes

  • Patients with mild-to-severe renal impairment have been reported to experience prolonged QT intervals. 
  • FDA received reports about torsades-de-pointes that were caused by famotidine.

• Vitamin B 12 deficiency:

  • Long-term treatment (>=2 year) can lead to vitamin B12 malabsorption and then vitamin B12 deficiency.
  • The severity of the deficiency depends on the dose. It is more severe in women than in men (30 years). Prevalence decreases after stopping therapy.

• Gastric cancer:

  • The presence of gastric cancer is not exempted from treatment.

• Renal impairment

  • Take caution; there is a greater risk of CNS adverse effects and QT prolongation.
  • Dosage adjustment is recommended for mild and chronic renal impairment (CrCl =60mL/minute).

Famotidine: 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

Monitoring parameters:

• CBC,
• gastric pH,
• Occult blood with GI bleeding

How to administer Famotidine (Pepcid)?

IV push:

• Administer over at least 2 minutes.

Solution for infusion:

• Administer over 15 to 30 minutes.

Oral:

• Administer without regard to meals. May administer with antacids.

Suspension:

• Shake vigorously before use.

Tablet (OTC):

• Do not chew.
• To prevent symptoms, administer 10 to 60 minutes before eating food or drinking beverages known to cause heartburn.

Mechanism of action of Famotidine (Pepcid):

It inhibits competitively histamine at H-1 receptors in the gastric parietal cell cells. This inhibits gastric acid production.

The onset of action when orally administered: Antisecretory effect:

• Within 1 hour

Peak antisecretory effect:

• Oral: Within 1 to 3 hours (dose-dependent);
• IV: Within 30 minutes

The duration of its antisecretory effect:

• IV, Oral: 10 to 12 hours

Absorption when administered orally:

• Incompletely absorbed

Protein binding:

• 15% to 20%

Metabolism:

• 30% to 35%;
• It has minimal first-pass metabolism and forms one metabolite (S-oxide)

Bioavailability when administered orally:

• 40% to 45%

Half-life elimination:

• IV:
  • Infants: ≤3 months: 8.1 ± 3.5 hours to 10.5 ± 5.4 hours;
  • Infants >3 to 12 months: 4.5 ± 1.1 hours
  • Children <11 years: 3.38 ± 2.6 hours
  • Children ≥11 years and Adolescents ≤15 years: 2.3 ± 0.4 hours
  • Adults: 2.5 to 3.5 hours;
  • The half-life is prolonged with renal impairment;
    • Oliguria: >20 hours;
    • Anuria: 24 hours

Time to peak, serum:

• Oral: About 1 to 3 hours

Excretion:

• Urine (25% to 30% when administered orally, 65% to 70% when administered IV as unchanged drug).

International Brand Names of Famotidine:

• Acid Controller Max St
• Acid Controller Original Str
• Acid Reducer Maximum Strength
• Acid Reducer
• Heartburn Relief Max St
• Heartburn Relief
• Pepcid
• Pepcid AC Maximum Strength
• ALTI-Famotidine
• APO-Famotidine
• BCI-Famotidine
• CO Famotidine
• Famotidine Omega W-O Preserv
• Famotidine Omega W-Preserv
• GMD-Famotidine
• MYLAN-Famotidine
• NTP-Famotidine
• TEVA-Famotidine
• Acifam
• Androtin
• Antiflam
• Antodine
• Aulzadin
• Ausfam
• Bestidine
• Corocyd
• Denufam
• Durater
• Facid
• Facidex
• Fadin
• Fadine
• Fadul
• Famagen
• Famatel
• Famo
• Famoc
• Famocid
• Famodar
• Famodil
• Famodin
• Famodine
• Famogal
• Famogard
• Famonerton
• Famopsin
• Famosan
• Famosia
• Famotaz
• Famotec
• Famotid
• Famotin
• Famowal
• Famox
• Famozol
• Faradin
• Farotin
• Ferotine
• Fibonel
• Fudone
• Fuweidin
• Gasafe
• Gasmodin
• Gaster
• Gastren
• Gastridin
• Gastril
• Gastrium
• Gastro
• Gastrodomina
• Gastrum
• H2 Bloc
• Hista-Bloc
• Interfam
• Keamotin
• Kimodin
• Logos
• Ludex
• Modin
• Motiax
• Motidin
• Navatac
• Nulcerin
• Nulcex
• Pamacid
• Pepcid
• Pepcid AC
• Pepcidac
• Pepcidin
• Pepcidina
• Pepcidine
• Pepdif
• Pepdine
• Pepfamin
• Peptifam
• Peptoci
• Pepzan
• Pharmotidine
• Quamatel
• Quamtel
• Sedanium-R
• Snow
• Stadin
• Stomax
• Supertidine
• Tarpan
• Tismafam
• Topcid
• Ulcatif
• Ulcelac
• Ulcenol
• Ulceran
• Ulfadin
• Ulfagel
• Ulfamid
• Ulmo
• Vesmo-20
• Voker
• Weimok
• Winiful
• Yamadin

Famotidine Brand Names in Pakistan: