Pharmacokinetics of moxalactam in patients with renal insufficiency

Moxalactam pharmacokinetics were determined in 18 patients with renal insufficiency (creatinine clearance, 0 to 99 ml/min). Each patient was given 0.5 g of moxalactam intramuscularly. Drug half-life ranged from 4.1 to 49.1 h and correlated inversely with creatinine clearance (r = -0.97). Total body drug clearance ranged from 0 to 88 ml/min, and renal clearance ranged from 0 to 57 ml/min. In four patients studied during hemodialysis, drug half-life was 21.7 +/- 7.5 h (mean +/- standard error) between dialyses and 4.4 +/- 0.5 h during dialysis. Moxalactam dialysance averaged 44 +/- 2 ml/min per m2 of dialyzer surface area, and approximately 50% of the drug was removed during a single hemodialysis. We confirmed that moxalactam is eliminated from the body primarily by renal excretion. Recommendations are given for dosage adjustment in patients with renal insufficiency.