About benzylpenicillin
Natural penicillin antibiotic
Used for
- Serious infections caused by susceptible bacteria, including streptococcal infections
- Meningitis, endocarditis, and syphilis when appropriate
- Prevention or treatment of infections in selected high-risk situations
Usual adult dose
Usually 1–4 million units intravenously every 4–6 hours; higher doses may be used for severe infections.
Usual dose in children
Usually 100,000–400,000 units/kg/day intravenously, divided every 4–6 hours; infection and age determine dosing.
Common side effects
- Allergic reactions, including rash or severe allergy
- Diarrhea, nausea, or vomiting
- Injection-site pain or inflammation
- Seizures or electrolyte disturbances, especially with high doses
Important warnings
- Serious or fatal allergy can occur, particularly with previous penicillin allergy.
- Dose adjustment may be needed with kidney impairment.
- High-dose treatment may affect potassium or sodium levels, depending on formulation.
- Use only for infections caused by susceptible bacteria; resistance occurs.
Pregnancy
Generally considered usable during pregnancy when clinically indicated; available evidence has not shown increased birth-defect risk.
Breastfeeding
Usually compatible with breastfeeding; small amounts enter milk and may rarely affect the infant’s digestion or cause rash.
Interactions
- Probenecid can increase benzylpenicillin concentrations.
- Methotrexate toxicity may increase.
- Warfarin effects may change; monitoring may be needed.
- Some antibiotics can reduce its antibacterial effect when used together.
AI-generated from general medical knowledge, not from this product's official leaflet. It may be incomplete or out of date. Not medical advice — ask a pharmacist or doctor before making any decision.