Therapeutic trial of trimethoprim as a potentiator of sulphonamides in gonorrhoea.

Abstract

Trimethoprim, an antifolic acid agent, inhibits the enzyme dihydrofolic acid reductase in bacteria, with little or no activity against the corresponding enzymes of mammalian species. Both in vitro and in vivo this compound markedly potentiates the antibacterial activity of sulfonamides. Trimethoprim and sulfonamides were given singly and in combination to 245 male patients with gonorrheal urethritis. Trimethoprim alone had no therapeutic effect. When given in combination with sulfonamides it greatly increased the cure rate to a level comparable to current therapeutic results with penicillin or tetracycline. This attributed to synergistic rather than to simple additive action.