CLINICAL EVALUATION OF PIVMECILLINAM IN INTRACTABLE URINARY-TRACT INFECTIONS WITH COMPLICATIONS

A COMPARATIVE STUDY WITH AMOXICILLIN BY A RANDOMIZED DOUBLE-BLIND TECHNIQUE

Abstract

Pivmecillinam is a new synthetic penicillin1) for oral use which was developed in 1972 by LUND, et al. The molecule is a new type of 6-aminopenicillanic acid derivative, of which the 6-position substitute is combined with an amidino structure (Fig. 1).
Pivmecillinam is converted to mecillinam at the time of absorption through the intestinal walls by the action of non-specific esterases, the pivaloyloxymethyl-ester moiety at the 3-posi-tion of the molecule being hydrolyzed to give mecillinam which is the antimicrobially active form of pivmecillinam.
As mecillinam has a potent antibacterial activity against Gram-negative bacteria, pivmecillinam has mainly been evaluated for treatment of urinary-tract infections 2-5). We have previously performed a double-blind comparative study on pivmecillinam for treatment of acute simple cystitis using amoxicillin as control 6). The results have indicated that pivmecillinam is significantly superior to amoxicillin in efficacy as well as about adverse reactions with such a small dosage [150mg (potency)/day] as one-fifth the dosage of amoxicillin.
The good results obtained with pivmecillinam in treatment of simple cystitis have prompted us to evaluate the efficacy and safety of the drug in treatment of intractable complicated urinary-tract infections using amoxicillin as reference drug.