About benzathine benzylpeni
Long-acting penicillin antibiotic
Used for
- Treats certain streptococcal infections, including strep throat
- Treats syphilis and some other treponemal infections
- Prevents recurrent rheumatic fever
Usual adult dose
Depends on infection. Syphilis: 2.4 million units intramuscularly once for early disease; later disease generally weekly for three weeks. Strep throat: usually one intramuscular dose.
Usual dose in children
Depends on indication and weight. Strep throat: one intramuscular dose, typically 600,000 units below 27 kg or 1.2 million units at or above 27 kg.
Common side effects
- Injection-site pain or swelling
- Nausea or diarrhea
- Rash or allergic reaction
- Rare severe allergic reaction
Important warnings
- For deep intramuscular injection only; never inject into a vein or artery.
- Do not use with a serious penicillin allergy.
- Not suitable for neurosyphilis or ocular syphilis; other treatment is needed.
- Severe, sometimes fatal reactions have occurred after accidental vascular injection.
Pregnancy
Generally used when indicated; penicillin is the recommended treatment for syphilis during pregnancy.
Breastfeeding
Usually compatible; small amounts may enter milk and rarely affect the infant’s gut or cause allergy.
Interactions
- Probenecid may increase penicillin levels.
- Tetracyclines may reduce penicillin’s antibacterial effect.
- Methotrexate toxicity may increase.
- Oral typhoid vaccine may work less well during antibiotic treatment.
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 It may be incomplete or out of date.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.