Indications: throat infections, otitis media, endocarditis, meningococcal disease, pneumonia, cellulitis, anthrax; prophylaxis in limb amputation; early or late latent syphilis.

Cautions: history of allergy; false-positive urinary glucose (if tested for reducing substances); renal impairment.

Contra-indications: penicillin hypersensitivity.

Side Effects: hypersensitivity reactions including urticaria, fever, joint pains, rashes, angioedema, anaphylaxis, serum sickness-like reaction; rarely CNS toxicity including convulsions (especially with high doses or in severe renal impairment), interstitial nephritis, haemolytic anaemia, leucopenia, thrombocytopenia, and coagulation disorders; also reported diarrhoea (including antibiotic-associated colitis.

Dose: by IM injection, child over 25 kg and adults, 400, 000 units (300 mg procaine penicillin and 60 mg benzyl penicillin sodium) 24-hourly or 12-hourly.

Child under 25 kg, according to body weight, Acute uncomplicated gonorrhoea, 2.4-4.8 g as a single dose. Syphilis 1.2 g daily for 10-14 days.