Correspondence with a pioneer, Jürgen Lehmann (1898-1989), producer of the first effective antituberculosis specific.

Correspondence between the author and Lehmann provided evidence that the latter evolved the first effective antituberculosis drug, para-aminosalicylic acid (PAS), contrary to accepted belief that this honour belonged to Nobel Prize-winner Selman A. Waksman for his production of streptomycin. While both drugs appeared in 1943, successful animal and clinical trials of PAS preceded those of streptomycin. PAS has been discarded in modern treatment regimens because of gastric side-effects, but was available at a critical time to demonstrate the principle of multiple therapy in prevention of bacterial resistance in tuberculosis therapy. It probably saved streptomycin, which causes bacterial resistance and clinical regression within 3 months when used alone, from being discarded as an unsuitable drug of temporary benefit and a public health hazard.