Benzathine Penicillin is a long-acting bactericidal antibiotic that causes cell lysis. It is used for the treatment of the following conditions:

• For secondary prophylaxis in patients with a history of acute glomerulonephritis.
• Treatment of mild to moderate upper respiratory tract infections caused by streptococci susceptible to low, prolonged serum concentrations of penicillin G.
• For secondary prophylaxis of rheumatic fever and chorea
• For secondary prophylaxis of rheumatic heart disease.
• For the treatment of syphilis, yaws, bejel, and pinta
• As Off-Label use of Group A Streptococcal chronic carriage

Benzathine Penicillin G Dose in Adults

Penicillin G benzathine is typically given as a shot into the muscle. The usual dose ranges from 1.2 to 2.4 million units, and it's given just once.

Group A Streptococcus:

• Acute Pharyngitis (Strep Throat):
  • Treatment: 1.2 million units given as a single shot into the muscle.
• Secondary Prophylaxis for Rheumatic Fever:
  • Prevention of Recurrent Attacks: 1.2 million units injected into the muscle once every 21 to 28 days. Duration varies based on risk factors and heart valve disease.
• Manufacturer's Labeling:
  • Prescribing Information Dosing: 600,000 units injected into the muscle every 2 weeks.
• Secondary Prophylaxis of Glomerulonephritis:
  • Prevention: 1.2 million units injected into the muscle every 4 weeks, or 600,000 units given twice monthly.
• Off-Label Use for Chronic Carriage:
  • Treatment: 1.2 million units injected into the muscle as a single dose, combined with oral rifampin.
• Note:
  • Most people with chronic carriage don't typically need antibiotics.

Benzathine Penicillin G Use in the treatment of syphilis:

• Primary, Secondary, Early Latent Syphilis (<1 year duration):
  • Treatment: 2.4 million units given as a single shot into the muscle.
• Late Latent, Latent with Unknown Duration, or Tertiary Syphilis (with normal CSF examination):
  • Treatment: 2.4 million units injected into the muscle once weekly for 3 doses.
• Neurosyphilis (including Ocular Syphilis):
  • Not indicated for initial treatment; aqueous penicillin G Intravenous is preferred.
  • After initial IV treatment, may consider penicillin G benzathine: 2.4 million units injected into the muscle once weekly for 3 weeks.
• Yaws, Bejel, and Pinta:
  • Treatment: 1.2 million units given as a single shot into the muscle.

Benzathine Penicillin G Dose in Children

Benzathine Penicillin G Dose in the treatment of Group A streptococcal upper respiratory tract infection:

Rheumatic Fever, Primary Prevention:

• Infants, Children, and Adolescents:
  • ≤27 kg: 600,000 units injected into the muscle as a single dose.
  • 27 kg: 1.2 million units injected into the muscle as a single dose.

Rheumatic Fever, Secondary Prevention:

• Note: Duration of secondary rheumatic fever prophylaxis varies depending on the condition:
  • Rheumatic fever with carditis and residual heart disease: 10 years or until 40 years of age (whichever is longer), sometimes lifelong prophylaxis.
  • Rheumatic fever with carditis but no residual heart disease: 10 years or until 21 years of age (whichever is longer).
  • Rheumatic fever without carditis: 5 years or until 21 years of age (whichever is longer).
• Infants, Children, and Adolescents:
  • ≤27 kg: 600,000 units injected into the muscle every 3-4 weeks.
  • 27 kg: 1.2 million units injected into the muscle every 3-4 weeks.

Penicillin G Benzathine use in the treatment of Syphilis:

Primary, Secondary, or Early Latent Syphilis (<1 year duration):

• Infants, Children, and Adolescents:
  • Dosage: 50,000 units/kg injected into the muscle once, up to a maximum dose of 2.4 million units.

Late Latent or Latent with Unknown Duration:

• Infants, Children, and Adolescents:
  • Dosage: 50,000 units/kg injected into the muscle once weekly for 3 doses, up to a maximum dose of 2.4 million units.

Pregnancy Risk Factor: B

• Animal studies haven't shown any adverse effects during pregnancy.
• Penicillin G benzathine can pass through the placenta from the mother to the fetus.
• Generally, when mothers use penicillins during pregnancy, it hasn't led to more risks for the baby.
• Penicillin G is the preferred treatment for syphilis in pregnant women, according to the CDC.

Penicillin G use during breastfeeding:

• Soluble penicillin G can be found in breast milk.
• The manufacturer advises caution when giving penicillin to nursing mothers.
• Effects on breastfed babies could involve changes in gut bacteria and potential allergic reactions, which may not be directly related to the dose.

Benzathine Penicillin G Dose in Renal Disease:

• The manufacturer's instructions don't include specific dosage adjustments for people with kidney problems.
• However, it's recommended to be cautious when using penicillin G benzathine in individuals with kidney impairment.

Benzathine Penicillin G Dose in Liver Disease:

• The manufacturer's instructions don't include specific dosage adjustments for individuals with liver issues.
• It's advisable to exercise caution when using penicillin G benzathine in people with liver impairment.

Frequency not defined:

• Cardiovascular:
  • Cerebrovascular Accident
  • Hypotension
  • Palpitations
  • Syncope
  • Tachycardia
  • Vasodilatation
  • Vasospasm
  • Vasodepressor Syncope
• Central Nervous System:
  • Anxiety
  • Coma
  • Confusion
  • Dizziness
  • Drowsiness
  • Euphoria
  • Fatigue
  • Headache
  • Localized Warm Feeling
  • Nervousness
  • Neurologic Abnormality (Neurogenic Bladder)
  • Numbness
  • Pain
  • Seizure
  • Transverse Myelitis
• Dermatologic:
  • Diaphoresis
  • Gangrene Of Skin Or Other Tissue
  • Pallor
  • Skin Mottling
  • Skin Ulceration at the injection site
• Gastrointestinal:
  • Bloody Stools
  • Intestinal Necrosis
  • Nausea
  • Vomiting
• Genitourinary:
  • Hematuria
  • Impotence
  • Priapism
  • Proteinuria
• Hematologic & Oncologic:
  • Local Hemorrhage at the injection site
  • Lymphadenopathy
• Hepatic:
  • Increased Serum Ast
• Hypersensitivity:
  • Hypersensitivity Reaction
• Immunologic:
  • Jarisch-Herxheimer Reaction
• Local:
  • Abscess
  • Atrophy
  • Bruising
  • Cellulitis
  • Localized Edema
  • Inflammation at the injection site
  • Injection Site Reaction & Neurovascular Damage
  • Pain At Injection Site
  • Residual Mass At Injection Site
  • Tissue Necrosis At Injection Site
• Neuromuscular & Skeletal:
  • Arthropathy
  • Exacerbation Of Arthritis
  • Periosteal Disease
  • Rhabdomyolysis
  • Tremor
  • Weakness
• Ophthalmic:
  • Blindness
  • Blurred Vision
• Renal:
  • Increased Blood Urea Nitrogen
  • Increased Serum Creatinine
  • Myoglobinuria
  • Renal Failure
• Respiratory:
  • Cyanosis

Contraindication to Benzathine Penicillin G Include:

• If someone has a known allergy to penicillin or any ingredient in the medicine, they should not use penicillin G benzathine.
• Allergic reactions to penicillin can be severe and even life-threatening, so it's crucial to avoid it if there's a known allergy.

Warnings and Precautions

Hypersensitivity reactions

• People with a history of hypersensitivity reactions, especially to penicillins or cephalosporins, need to be cautious when using penicillin G benzathine.
• Serious and sometimes fatal allergic reactions (anaphylaxis) have occurred in some patients.
• These reactions may require immediate emergency treatment, including epinephrine, oxygen, intravenous steroids, and airway management, such as intubation, if necessary.

Superinfection

• Extended use of penicillin G benzathine can lead to superinfections caused by fungi or bacteria.
• These superinfections might include conditions like C. difficile-associated diarrhea (CDAD) and pseudomembranous colitis.
• It's important to note that CDAD can occur more than 2 months after finishing antibiotic treatment.

Renal impairment

• It's important to be cautious when administering penicillin G benzathine to patients with kidney problems.
• Although specific dosage adjustments are not provided in the manufacturer's labeling, extra care is advised in individuals with renal impairment.

Seizure disorders:

• Patients with a history of seizure disorders should use penicillin G benzathine cautiously.
• High levels of the medication, especially in individuals with kidney problems, may elevate the risk of seizures.

Use of Syphilis or Neurosyphilis:

• The CDC and AAP do not currently recommend using penicillin G benzathine as the initial treatment for congenital syphilis or neurosyphilis.
• This recommendation is due to reported instances of treatment failures and a lack of published clinical data supporting its effectiveness in these specific cases.

Monitoring Parameters:

• Pay attention for signs and symptoms of anaphylaxis during the first dose.
• Anaphylaxis can include severe allergic reactions like difficulty breathing, swelling, or a sudden drop in blood pressure.
• If any signs of anaphylaxis occur, seek immediate medical help.

How to administer Benzathine Penicillin G?

Intramuscular Administration

• Warm Before Injection: Bring the medication to room temperature before giving the injection to reduce pain.
• Injection Site: Administer deeply into the upper outer quadrant of the buttock.
• Avoid Arteries and Nerves: Ensure injections are not near arteries or nerves to prevent permanent neurological damage or gangrene.
• Rotation of Injection Site: When giving repeated doses, alternate the injection site to prevent tissue damage.
• Avoid Other Routes: Do not administer intravenously, intra-arterially, or subcutaneously.

Mechanism of action of Benzathine Penicillin G:

• Penicillin G benzathine works by messing up the process of making bacterial cell walls when the bacteria are actively multiplying.
• This messes them up so much that they die, which is why it's effective against certain types of bacteria.

Duration:

• Typically lasts from 1 to 4 weeks, depending on the dose.
• Higher doses lead to longer-lasting effects.

Absorption:

• Slow absorption when given intramuscularly.

Distribution:

• Minimal concentrations in the cerebrospinal fluid (CSF), even when the meninges are inflamed.
• Highest levels found in the kidneys.
• Lesser amounts in the liver, skin, and intestines.

Protein Binding:

• About 60% of the drug binds to proteins in the body.

Time to Peak Serum:

• Usually reaches peak levels in the bloodstream within 12 to 24 hours.
• Detectable levels in the bloodstream can last 1 to 4 weeks, depending on the dose.

Excretion:

• Eliminated through renal tubular excretion.
• Penicillin G can be detected in urine for up to 12 weeks after a single intramuscular injection.
• Renal clearance may be slower in newborns, young infants, and people with kidney problems.

Benzathine Penicillin International Brands:

• Bencelin
• Benzapen
• Benzetacil
• Benzetacil L.A.
• Benzibiotic
• Bepeben
• Bicillin G
• Bicillin L-A
• Debecylina
• Deposilin
• Extencilline
• Indopen
• Lentocilin-S
• Leomypen
• Longacillin
• Mycin
• Noraben
• Pen Di Ben
• Penadur
• Penadur - LA
• Penadur LA
• Pencom
• Pendepon
• Pendiben L-A
• Pendysin
• Penidure
• Penilente LA
• Penzathine
• Retarpen
• Retarpen LA
• Tardocillin
• Terbocyl
• Ultracillin LA
• Unicil L-A
• Zalpen

Benzathine Penicillin in Pakistan: