Rifampicin: a new rifamycin

ABSTRACT

The results obtained from the study of absorption, diffusion and elimination of 3-(4-methylpiperazinyliminomethyl) rifamycin SV(rifampicin, AMP) in humans show that the aim of obtaining a new rifamycin well absorbed when administered by mouth has been reached with the synthesis of this antibiotic. After oral administration of 150 mg, AMP is found in the blood serum in therapeutically active concentrations during about 8th. When the dose is increased to 450 mg, serum levels are present for about 24h, and with 900mg they are very high and long-lasting. The elimination of the antibiotic is slow and takes place mainly in the bile, although bactericidal concentrations are found also in the urine. The half-life has thus a high value, while the total clearance is low. Furthermore, AMP shows a high distribution volume, which points to a very good difusion confirmed by the direct determinations of the antibiotic in the different organs and body fluids.