Long-acting penicillins: historical perspectives.

For the more than three decades since benzathine penicillin G was discovered it remains unique as the only antibiotic formulation that can provide serum drug concentrations for several weeks following a single intramuscular injection. Benzathine penicillin G has withstood the test of time as the ideal drug to treat early, infectious syphilis and to prevent and treat Group A streptococcal infections. It has proved to be extraordinarily effective for the prevention of rheumatic fever recurrences and is a major reason for the marked reduction in the morbidity and mortality in countries where carefully monitored prophylaxis programs have been established.