Benzathine penicillin is the Penicillin G preparation with the longest duration, particularly used for syphilis treatment and prophylactic purposes. It is administered intramuscularly and is preferred due to its slow absorption and prolonged effectiveness.
The Penicillin G preparation with the longest duration is long-acting benzathine penicillin. This formulation is recommended for the treatment of syphilis, where a single intramuscular injection can cure primary, secondary, or early latent syphilis. For late latent or tertiary syphilis, a series of three injections administered at weekly intervals is usually necessary. Referring to the American Heart Association, the regimen may include benzathine benzylpenicillin every 3 or 4 weeks for prophylactic purposes.
Penicillin G, also a treatment for a variety of bacterial infections including pneumonia, cannot be taken orally due to its instability in acidic conditions. Benzathine penicillin, a derivative of Penicillin G, features extended duration due to its slower absorption and release, making it effective for extended treatment protocols.
Therefore, benzathine penicillin is the Penicillin G preparation with the longest duration, often used in the management of syphilis and prophylactic treatment depending on the stage and risk of reinfection.