Bismuth penicillin in the treatment of acute syphilitic orchitis of rabbits.

THE TREATMENT of syphilis in human beings with penicillin alone usually results in failures averaging from 15 to 20 per cent. Thus L. Altschuler and co-workers 1 reported on a large number of patients so treated an incidence of failure in seronegative primary syphilis of 8.7 per cent, in seropositive primary syphilis of 18.6 per cent and in secondary syphilis of 28.3 per cent. Other observers have reported similar results. It is thus apparent that treatment with penicillin alone is not the complete answer to this problem. In 1947 Monash 2 prepared a number of insoluble salts of penicillin the administration of which, because of their slow rate of absorption, resulted in the production of prolonged penicillin blood levels in rabbits. One of these salts, namely bismuth penicillin, immediately suggested itself as a possible improvement over penicillin alone in the treatment of syphilis. Kolmer and Rule during the past