About benzathine penicillin
Long-acting penicillin antibiotic
Used for
- Treats strep throat and other susceptible bacterial infections
- Treats syphilis
- Prevents recurrent rheumatic fever
Usual adult dose
Varies by infection; syphilis is commonly treated with one or more weekly intramuscular doses.
Usual dose in children
Weight-based intramuscular dosing; schedules vary by infection and age.
Common side effects
- Injection-site pain or swelling
- Nausea or diarrhea
- Rash or other allergic reactions
- Rare severe allergic reaction
Important warnings
- For deep intramuscular injection only; never inject intravenously.
- Serious, potentially fatal allergy can occur, especially with penicillin allergy.
- Use only for infections caused by susceptible bacteria; it does not treat viral infections.
- Syphilis treatment schedules depend on stage; follow clinical guidance.
Pregnancy
Generally considered appropriate when needed; it is the preferred treatment for syphilis during pregnancy.
Breastfeeding
Usually compatible; small amounts enter milk and may rarely affect the infant’s gut or cause rash.
Interactions
- Probenecid may increase penicillin levels.
- Methotrexate toxicity may increase.
- May reduce effects of live oral typhoid vaccine.
- Other antibiotics may affect treatment; clinical review is appropriate.
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 It may be incomplete or out of date.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.