Prescription under medical supervision

Therapeutic action

– Long-acting penicillin antibacterial


– Early syphilis (primary, secondary, or early latent infection of less than 12 months duration)
– Late latent syphilis (infection of more than 12 months duration or of unknown duration)
– Congenital syphilis (absence of clinical signs in the neonate and adequate treatment in the mother)
– Endemic treponematoses (yaws, bejel, pinta)
– Streptococcal tonsillitis 
– Prophylaxis of diphtheria in the event of direct contact
– Primary and secondary prophylaxis of rheumatic fever

Forms and strengths, route of administration

– Powder for injection in vials of:
• 1.2 MIU (900 mg), to be dissolved in 4 ml of water for injection, for IM injection
• 2.4 MIU (1.8 g), to be dissolved in 8 ml of water for injection, for IM injection


– Syphilis
Child: 50 000 IU (37.5 mg)/kg per injection (max. 2.4 MIU or 1.8 g per injection)
Adult: 2.4 MIU (1.8 g) per injection

– Yaws, bejel, pinta
Child under 10 years: 1.2 MIU (900 mg) per injection
Child 10 years and over and adult: 2.4 MIU (1.8 g) per injection

– Streptococcal tonsillitis, prophylaxis of diphtheria, prophylaxis of rheumatic fever
Child under 30 kg: 600 000 IU (450 mg) per injection
Child 30 kg and over and adult: 1.2 IU (900 mg) per injection


 Early syphilis, congenital syphilis, tonsillitis, yaws, bejel, pinta, prophylaxis of diphtheria, primary prophylaxis of rheumatic fever: single dose; late latent syphilis: one injection/week for 3 weeks; secondary prophylaxis of rheumatic fever: one injection every 4 weeks for several years

Contra-indications, adverse effects, precautions

– Do not administer to penicillin-allergic patients.
– Administer with caution to patients allergic to cephalosporins (cross-sensitivity may occur) and renal impairment (reduce dosage).
– May cause:
• gastroinstestinal disturbances, pain at injection site, allergic reactions sometimes severe;
• Jarisch-Herxheimer reaction (fever, chills, myalgia, tachycardia) in patients with syphilis;
• convulsions in the event of high dosages or renal impairment;
• symptoms of shock with neuropsychiatric disorders in case of accidental IV injection.
– Ensure that the IM injection does not enter a blood vessel.
– Do not combine with methotrexate.
– Pregnancy and breast-feeding: no contra-indication


– For a 2.4 MIU (1.8 g) dose, administer 1.2 MIU (900 mg) in each buttock.
– Do not confuse long-acting benzathine benzylpenicillin, for IM injection, with rapidly acting benzylpenicillin (or penicillin G), administered by Iv route.
– Do not mix with other drugs in the same syringe.
– Storage: below 25 °C -  - 
Once reconstituted, suspension must be used immediately.