The Disposition of Mecillinam and Pivmecillinam in Man

Abstract

Peak serum mecillinam concentrations of 5–6 μg/ml were obtained after an intramuscular injection of mecillinam and concentrations of about 2 μg/ml and 3 μg/ml after capsules containing doses of 200 mg and 400 mg of pivmecillinam respectively in volunteers lying supine in beds. A six day course of two 200 mg capsules of pivmecillinam taken four times a day did not significantly alter the plasma mecillinam concentration/time profile. Two 500 mg probenecid tablets taken before 400 mg of pivmecillinam reduced the urinary clearance of mecillinam and increased the peak serum concentrations to between 4 and 5 µg/ml. Moderate activity resulted in higher serum mecillinam concentrations probably due to an increase in absorption efficiency.