Benzathine benzylpenicillin (rINN) is a form of penicillin also known as benzathine penicillin. It is an antibiotic useful for the treatment of a number of bacterial infections.
It is slowly absorbed into the circulation, after intramuscular injection, and hydrolysed to benzylpenicillin in vivo. It is the drug-of-choice when prolonged low concentrations of benzylpenicillin are required and appropriate, allowing prolonged antibiotic action over 2–4 weeks after a single IM dose. It is marketed by Wyeth under the trade name Bicillin L-A.