KW-1070 (FORTIMICIN), A NOVEL BROAD-SPECTRUM AMINOGLYCOSIDE ANTIBIOTIC: IN VITRO ANTIBACTERIAL ACTIVITY, PHARMACOKINETICS AND CLINICAL EVALUATION

Abstract

We have examined the antibacterial activity and the pharmacokinetics as well as the therapeutic efficacy against surgical infections of KW-1070 (fortimicin), a novel aminoglycoside antibiotic.
The antibacterial activity of KW-1070 against gram-negative bacteria was similar to that of amikacin: it was slightly more active than amikacin against S. marcescens, but less active against P. aeruginosa. KW-1070 was active against isolates of S. marcescens multiply resistant to aminoglycoside antibiotics including gentamicin.
The pharmacokinetics of KW-1070 administered intramuscularly were studied in three healthy male volunteers. Volunteers given 200mg of KW-1070 had peak serum concentration within 60 min ranging from 11.2 to 14.0μg/ml. The pharmacokinetic parameters were calculated as follows: T 1/22.08 h; Kel 0.42 h^-1; T-max 0.45 h; C-max 11.3μg/ml, Vd 14.6 1; AUC 32.1 (μg/ml) h.
The urinary excretion rate within 6h was averaged 42.3% of the dose.
Twelve out of sixteen patients with various surgical infections responded well to the treatment with mainly 200mg of KW-1070 twice a day for 7 to 14 days.
The elevation of transaminase in two cases and that of BUN in three cases were encountered during the therapy.