The Use of Dihydrostreptomycin in the Treatment of Tuberculosis

¹ Division of Medicine, Mayo Clinic, Rochester, Minnesota.
² The Mineral Springs Sanatorium, Cannon Falls, Minnesota.
³ The Section on Otolaryngology and Rhinology, Mayo Clinic, Rochester, Minnesota.

Dihydrostreptomycin, a derivative of streptomycin, has been reported to be as effective as the parent drug against the tubercle bacillus in vitro and against experimental tuberculosis in various animals. The neurotoxicity of the two drugs has also been studied experimentally and dihydrostreptomycin has been reported to be less toxic than streptomycin.

The present report summarizes our experience with the first 35 patients whom we treated with the new drug. Dihydrostreptomycin was found to be less neurotoxic than streptomycin, only four of 26 patients showing any sign or symptom of vestibular damage when a daily dose of 2 gm. was given for long periods. Two patients noted slight deafness after treatment was completed and audiograms revealed the development of deafness for the high frequencies in one of them. No allergic reactions occurred, although nine of these 35 patients had 7.5 per cent or more of eosinophils. No other changes in the blood were noted. Studies of function of liver and kidneys did not reveal damage to these organs. Dihydrostreptomycin seemed to be as effective as streptomycin in the treatment of various types of tuberculosis, but much more work must be done to determine if the same doses of the two drugs are equally effective. The frequency of dihydrostreptomycin-resistant strains of tubercle bacilli is not yet known, but three of these patients discharged resistant organisms during treatment, one of them after only 18 days of therapy.