Formulary
Benzathine benzylpenicillin: Indications, Dosing, Side Effects and Interactions
The penicillins are bactericidal and act by interfering with bacterial cell wall synthesis.
MedNext Academy | 6 min read
Benzathine benzylpenicillin: Indications, Dosing, Side Effects and Interactions
The penicillins are bactericidal and act by interfering with bacterial cell wall synthesis.
Drug action
The penicillins are bactericidal and act by interfering with bacterial cell wall synthesis. They diffuse well into body tissues and fluids, but penetration into the cerebrospinal fluid is poor except when the meninges are inflamed. They are excreted in the urine in therapeutic concentrations.
Indications and dose
**Erysipelas,Yaws,Pinta,Prevention of secondary case of diphtheria**
- **Adult** (By Deep Intramuscular Injection): 1.2 million units for 1 dose, outer quadrant of the gluteus maximus or Hochstetter's ventrogluteal field is the preferred site of injection.
**Early syphilis [primary, secondary, and early latent-less than 2 years since infection],Asymptomatic contacts of patients with infectious syphilis**
- **Adult** (By Deep Intramuscular Injection): 2.4 million units for 1 dose, outer quadrant of the gluteus maximus or Hochstetter's ventrogluteal field is the preferred site of injection, in the third trimester of pregnancy (week 28 onwards) the dose should be repeated after 7 days.
**Late latent syphilis [more than 2 years since infection]**
- **Adult** (By Deep Intramuscular Injection): 2.4 million units once weekly for 3 weeks, outer quadrant of the gluteus maximus or Hochstetter's ventrogluteal field is the preferred site of injection.
**Prophylaxis of rheumatic fever [without cardiac involvement],Prophylaxis of poststreptococcal glomerulonephritis [without cardiac involvement],Prophylaxis of erysipelas [without cardiac involvement]**
- **Adult** (By Deep Intramuscular Injection): 1.2 million units every 3-4 weeks for at least 5 years or up to 21 years of age (whichever is longer), outer quadrant of the gluteus maximus or Hochstetter's ventrogluteal field is the preferred site of injection.
**Prophylaxis of rheumatic fever [transient cardiac involvement],Prophylaxis of poststreptococcal glomerulonephritis [transient cardiac involvement],Prophylaxis of erysipelas [transient cardiac involvement]**
- **Adult** (By Deep Intramuscular Injection): 1.2 million units every 3-4 weeks for at least 10 years or up to 21 years of age (whichever is longer), outer quadrant of the gluteus maximus or Hochstetter's ventrogluteal field is the preferred site of injection.
**Prophylaxis of rheumatic fever [persistent cardiac involvement],Prophylaxis of poststreptococcal glomerulonephritis [persistent cardiac involvement],Prophylaxis of erysipelas [persistent cardiac involvement]**
- **Adult** (By Deep Intramuscular Injection): 1.2 million units every 3-4 weeks for at least 10 years or up to 40 years of age (whichever is longer); life-long prophylaxis may be necessary, outer quadrant of the gluteus maximus or Hochstetter's ventrogluteal field is the preferred site of injection.
**Erysipelas, Yaws, Pinta, Prevention of secondary case of diphtheria for benzathine benzylpenicillin**
- **Child (body-weight up to 30 kg)** (By deep intramuscular injection): 0.6 million units for 1 dose, mid-lateral thigh muscle is the preferred site of injection.
- **Child (body-weight 30 kg and above)** (By deep intramuscular injection): 1.2 million units for 1 dose, mid-lateral thigh muscle is the preferred site of injection.
**Early syphilis [primary, secondary, and early latent-less than 2 years since infection], Asymptomatic contacts of patients with infectious syphilis for benzathine benzylpenicillin**
- **Child 12-17 years** (By deep intramuscular injection): 2.4 million units for 1 dose, outer quadrant of the gluteus maximus or Hochstetter's ventrogluteal field is the preferred site of injection, in the third trimester of pregnancy (week 28 onwards) the dose should be repeated after 7 days.
**Late latent syphilis [more than 2 years since infection] for benzathine benzylpenicillin**
- **Child 12-17 years** (By deep intramuscular injection): 2.4 million units once weekly for 3 weeks, outer quadrant of the gluteus maximus or Hochstetter's ventrogluteal field is the preferred site of injection.
**Prophylaxis of rheumatic fever [without cardiac involvement], Prophylaxis of poststreptococcal glomerulonephritis [without cardiac involvement], Prophylaxis of erysipelas [without cardiac involvement] for benzathine benzylpenicillin**
- **Child (body-weight up to 30 kg)** (By deep intramuscular injection): 0.6 million units every 3-4 weeks for at least 5 years or up to 21 years of age (whichever is longer), mid-lateral thigh muscle is the preferred site of injection in children.
- **Child (body-weight 30 kg and above)** (By deep intramuscular injection): 1.2 million units every 3-4 weeks for at least 5 years or up to 21 years of age (whichever is longer), mid-lateral thigh muscle is the preferred site of injection in children.
**Prophylaxis of rheumatic fever [transient cardiac involvement], Prophylaxis of poststreptococcal glomerulonephritis [transient cardiac involvement], Prophylaxis of erysipelas [transient cardiac involvement] for benzathine benzylpenicillin**
- **Child (body-weight up to 30 kg)** (By deep intramuscular injection): 0.6 million units every 3-4 weeks for at least 10 years or up to 21 years of age (whichever is longer), mid-lateral thigh muscle is the preferred site of injection in children.
- **Child (body-weight 30 kg and above)** (By deep intramuscular injection): 1.2 million units every 3-4 weeks for at least 10 years or up to 21 years of age (whichever is longer), mid-lateral thigh muscle is the preferred site of injection in children.
**Prophylaxis of rheumatic fever [persistent cardiac involvement], Prophylaxis of poststreptococcal glomerulonephritis [persistent cardiac involvement], Prophylaxis of erysipelas [persistent cardiac involvement] for benzathine benzylpenicillin**
- **Child (body-weight up to 30 kg)** (By deep intramuscular injection): 0.6 million units every 3-4 weeks for at least 10 years or up to 40 years of age (whichever is longer); life-long prophylaxis may be necessary, mid-lateral thigh muscle is the preferred site of injection in children.
- **Child (body-weight 30 kg and above)** (By deep intramuscular injection): 1.2 million units every 3-4 weeks for at least 10 years or up to 40 years of age (whichever is longer); life-long prophylaxis may be necessary, mid-lateral thigh muscle is the preferred site of injection in children.
Cautions
History of allergy
Side effects
Common or very common Diarrhoea; hypersensitivity; nausea; skin reactions; thrombocytopenia; vomiting Uncommon Arthralgia; leucopenia Rare or very rare Agranulocytosis; angioedema; haemolytic anaemia; hepatic disorders; nephritis tubulointerstitial; neutropenia; pseudomembranous enterocolitis; seizure; severe cutaneous adverse reactions (SCARs) Side-effects, further information Diarrhoea frequently occurs during oral penicillin therapy. It is most common with broad-spectrum penicillins, which can cause antibiotic-associated colitis. Side-effects For benzathine benzylpenicillin Common or very common Increased risk of infection Uncommon Oral disorders Rare or very rare Nephropathy Frequency not known Antibiotic associated colitis; encephalopathy; Hoigne's syndrome; Jarisch-Herxheimer reaction
Pregnancy
Manufacturer advises not known to be harmful.
Breast feeding
Manufacturer advises present in milk in small amounts but not known to be harmful. Monitor infant for effects on the gastrointestinal flora; discontinue breast feeding if diarrhoea, candidiasis or rash in the infant occur.
Hepatic impairment
Manufacturer advises caution in impairment (possible risk of delayed metabolism and excretion in severe impairment).
Renal impairment
Manufacturer advises caution in impairment (possible risk of delayed metabolism and excretion in severe impairment). Dose adjustments Manufacturer advises reduce daily dose by 25% and give as a single dose if creatinine clearance 15-59 mL/minute; reduce daily dose by 50-80% and give in 2-3 divided doses if creatinine clearance less than 15 mL/minute (maximum 1-3 million units per day). See Prescribing in renal impairment .
Medicinal forms
Clinical governance
**Author:** MedNext Clinical Team. **Clinical reviewer:** Dr Shameer Deen, MBBS, MS, MRCS. **Sources:** BNF, Indian Pharmacopoeia, CIMS India. **Correction:** Report errors at support@mednext.academy.
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