Bay k 4999

A new semisynthetic ureidopenicillin (Bay K 4999) demonstrates favorably in vitro antibacterial efficacy against human-pathogenic gram-negative rods in comparison to mezlocillin and azlocillin. A comparative paramcokinetic study was done with 10 test subjects after 30 min intravenous infusion of 4.0 g of Bay K and mezlocillin, respectively. The serum concentration course during a period of 10 h showed an open three-compartment model for both antibiotics. The urine recovery of Bay K 4999 during 24 h was only 32.6 +/- 4.3% of the applied dose. In three test subjects with normal renal function, the average renal clearance of Bay K was 61.0, the total serum clearance was 409.2 ml/min/1.73 m2. 31 patients were treated with a daily dose of 3 x 1.0--2.0 g Bay K for severe bronchopulmonary, UTI and cholangiogenic infections. The therapeutic results were good; the relatively high number of side effects should be further investigated in animal studies and require more clinical experience.

In tests of 14 antibiotics against 26 A. anitratus strains isolated from nosocomial infections, Bay k 4999 [66327-51-3], ticarcillin [34787-01-4], and piperacillin (I) [61477-96-1] were the most active penicillins tested.Among the cephalosporins, cefotaxime [63527-52-6] was superior to cefsulodin [52152-93-9]; cephalothin [153-61-7] was not active at all.All strains were sensitive to tobramycin [32986-56-4] and amikacin [37517-28-5], but 1 netilmicin [56391-56-1]-resistant strain was isolated.A combination of a newer penicillin with either tobramycin or amikacin may be superior to cephalosporin-aminoglycoside combinations in treatment of A. anitratus nosocomial infections.