Sisomicin is a new antibiotic, derived fromMicromonospora inyoensis. The drug has a broad antiba-cterial spectrum; it is especially active againstPseudomonas aeruginosa. In sensitivity tests, the following results were obtained: E. coliandKlebsiella pneumoniaewere as sensitive to Sisomicin as to Gentamicin.Serratia marcescensis less susceptible to Sisomicin than to Gentamicin. AgainstPseudomonas aeruginosa, Sisomicin is more active than Gentamicin.
Sisomicin, 50 to 200mg/day, (300-1, 650 in total) was clinically administered for from 5 to 11 days.
Out of 6 patients with respiratory tract infection and 10 with urinary tract infections, 11 (73.3%) responded to therapy and were judged “effective”. In respiratory tract infections, Sisomicin treatment was “effective” in 1 and “ineffective” in 4 patients. The response of one patient could not be conclusively assessed. In urinary tract infections by E. coli, Enterococcus, Enterobacter, Proteus mirabilis and Pseudomonas aeruginosa, Sisomicin was “effective” in all 10 patients.
Audiometric tests of one patient were negative. Eosinophilia, elevations of GOT, GPT and Alkaline phosphatase values were recorded in one, and an increase in GOT and GPT in another patient.
