Human pharmacology of 6-[D-alpha-(3-guanylureido)-phenylacetamido]-penicillanic acid (BL-P1654).

BL-P1654 is a new alpha-substituted ureido penicillin which has broad-spectrum activity. Doses of 0.5 and 1.0 g administered by rapid intravenous injection produce mean peak serum concentrations of 40.7 and 80.8 mug/ml, respectively. The same doses administered by 1-h intravenous infusions produce mean peak serum concentrations of 22.6 and 47 mug/ml, respectively. The mean serum concentrations from 1 to 6 h after onset of administration of the drug are the same for both schedules. The mean serum concentration at 6 h after the rapid intravenous injection of 0.5- and 1.0-g doses of BL-P1654 are 3.4 and 5.4 mug/ml, respectively. A dose of 1.0 g every 4 h maintains a serum concentration of about 15 mug/ml. About 50 to 65% of the BL-P1654 is excreted in the urine during the first 6 h.