THE LABORATORY AND CLINICAL STUDIES OF PIVMECILLINAM AGAINST URINARY TRACT INFECTIONS

Abstract

The in vitro activity of mecillinam against bacteria isolated from infected urines, compared with that of ampicillin, is low against Staphylococcus epidermidis (MIC, more than 50 μg/ml), but remarkably high against E. coli strains (MIC, ≤=0.2-3.12μg/ml), even against those of ampicillin resistance, the MIC varies from 0.39 to 6.25 μg/ml.
Pivmecillinam was applied for the treatment of 85 cases of urinary tract infections. The cases were 72 of acute simple cystitis, 2 of prostato-cystitis, 6 of acute or chronic uncomplicated pyelonephritis and 5 of chronic complicated lower urinary tract infections. Fourty-two cases of acute simple cystitis and prostatocystitis were treated in a dose of 0.3-10mg divided two times a day, for the purpose of investigations on small dose therapy. The bacteriological response was gained 77.5% in these cases. In 32 cases of acute cystitis at a dose of 100mg to 600mg a day, the rate of effectiveness was 90.6%, even in the cases caused by penicillin-resistant strains, the cure rate was as high as 86.7%. In 6 cases of pyelonephritis, the rate was 50% in acute or chronic. Five complicated lower urinary tract infections were treated at a dose of 100-750mg a day for 2 weeks. Five of 3 were gained bacteriological response.
The side effects of pivmecillinam were the disturbances of gastrointestinal tract such as stomach distress, loss of appetite, loose stool, which were seen in 4.7%. No abnormal effects on BUN, creatinine, S-GOT and peripheral hematology were observed.
Conclusion
Mecillnam is suprior to other broad-spectrum penicillin derivatives such as ampicillin, amoxicillin, etc., principally against gram-negative bacteria, even against penicillin-resistant strains producing penicillinase.
Against the urinary tract infections due to gram-negative bacteria, especially caused by E. coli, including penicillin-resistant strains, pivmecillinam is an excellent chemotherapeutic agent of oral use.