Last reviewed · How we verify
Bicillin C-R (Penicillin G Benzathine)
Penicillin G inhibits bacterial cell-wall peptidoglycan biosynthesis, rendering the cell wall osmotically unstable.
Penicillin G benzathine is a beta-lactam antibiotic indicated for treatment of penicillin-susceptible infections including upper-respiratory tract infections and venereal infections, as well as prophylaxis for rheumatic fever. Its low solubility allows slow intramuscular release, producing prolonged but lower serum levels compared to other parenteral penicillins. Primary risk is hypersensitivity reaction in penicillin-allergic patients, and concurrent use with tetracyclines should be avoided. Effectiveness depends on bacterial susceptibility and appropriate dosing guided by culture and sensitivity testing.
At a glance
| Generic name | Penicillin G Benzathine |
|---|---|
| Sponsor | Pfizer |
| Drug class | Beta-lactam antibiotic |
| Target | Cell-wall peptidoglycan biosynthesis |
| Modality | Small molecule |
| Phase | FDA-approved |
| First approval | 1952 |
Mechanism of action
Penicillin G exerts a bactericidal action against penicillin-susceptible microorganisms during the stage of active multiplication. It acts through the inhibition of biosynthesis of cell-wall peptidoglycan, rendering the cell wall osmotically unstable. This mechanism is effective only against actively dividing bacteria and does not work against penicillinase-producing bacteria or organisms with altered penicillin-binding proteins.
Approved indications
- Erysipelas
- Pneumococcal pneumonia
- Pneumonia due to Streptococcus
- Scarlet fever
- Streptococcal infectious disease
- Streptococcus pyogenes infection
- Syphilis excluding neurosyphilis
Common side effects
- Injection site reactions (pain, inflammation, lump, abscess, necrosis, edema, hemorrhage, cellulitis, hypersensitivity, atrophy, ecchymosis, skin ulcer)
- Hypersensitivity reactions (skin eruptions, urticaria, laryngeal edema, fever, eosinophilia)
- Skin rashes
- Urticaria
- Serum sickness-like reactions (chills, fever, edema, arthralgia, prostration)
- Nausea
- Vomiting
- Dizziness
- Headache
- Fever
- Pruritus
- Fatigue
Serious adverse events
- Anaphylaxis including shock and death
- Stevens-Johnson syndrome (SJS)
- Toxic epidermal necrolysis (TEN)
- Drug reaction with eosinophilia and systemic symptoms (DRESS)
- Acute myocardial ischemia with or without myocardial infarction (Kounis syndrome)
- Pseudomembranous colitis
- Cardiac arrest
- Seizures
- Transverse myelitis
- Hoigne's syndrome
Drug interactions
- Tetracycline
- Probenecid
Primary sources
Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.
| Source | Used for |
|---|---|
| FDA label | Mechanism, indications, dosing, boxed warnings, drug interactions |
Competitive intelligence
For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:
- Bicillin C-R CI brief — competitive landscape report
- Bicillin C-R updates RSS · CI watch RSS
- Pfizer portfolio CI