Penicillin G Benzathine
Bicillin is a brand-name injectable antibiotic containing penicillin G benzathine, a long-acting form of penicillin. It is primarily used to treat syphilis and other infections caused by susceptible bacteria. The medication is administered via intramuscular injection and works by inhibiting bacterial cell wall synthesis, effectively eliminating the infection.
Bicillin is a long-acting injectable penicillin antibiotic used primarily to treat syphilis and other susceptible bacterial infections.
Key facts at a glance
- RxNorm
- 225110
- Generic
- Bicillin
- Class
- brand-name
- Brands
- —
- Availability
- rx
- Lactation
- unknown
- Routes
- —
- Forms
- —
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Bicillin is FDA-approved for treating syphilis (primary, secondary, and latent stages), as well as infections caused by susceptible strains of streptococci. It is also used for rheumatic fever prophylaxis and in treating yaws, bejel, and pinta. A healthcare provider determines the specific indication based on the infection type and severity.
Bicillin contains penicillin G benzathine, which works by interfering with bacterial cell wall synthesis. It binds to penicillin-binding proteins in susceptible bacteria, preventing the cross-linking of peptidoglycan chains that are essential for cell wall strength and rigidity. This leads to bacterial cell death. Its depot formulation allows for slow release, providing prolonged antibacterial activity.
Bicillin is administered as a deep intramuscular injection, typically into the gluteal muscle. Patients with penicillin allergies should not receive this medication. Common side effects may include pain at the injection site, allergic reactions, and gastrointestinal disturbances. It is essential to complete the full course of treatment as prescribed. This medication requires a prescription and should only be used under medical supervision.
Official drug label
WellAlly may earn a referral fee from linked resources at no extra cost to you. Editorial content is never influenced by commercial relationships.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed September 3, 2026. · Read our editorial policy