Pharmacokinetics of carumonam in patients with renal insufficiency

The pharmacokinetics of carumonam after a single 1,000-mg intravenous infusion (20 min) were evaluated in four groups of subjects who had various degrees of renal impairment: group 1, CLCR greater than 60 ml/min; group 2, CLCR = 30 to 60 ml/min; group 3, CLCR = 10 to 30 ml/min; and group 4, CLCR less than 10 ml/min). The elimination half-life of carumonam increased with decreasing creatinine clearance (CLCR) from 1.7 h in group 1 to 11.3 h in group 4. Peak carumonam concentration (103 micrograms/ml) and steady-state volume of distribution (12.8 liters) did not change with decreasing CLCR. Total body clearance (r = 0.98), renal clearance (r = 0.98), and nonrenal clearance (r = 0.67) of carumonam correlated with decreasing CLCR. Mean nonrenal clearance was 21 ml/min in group 1 and 12 ml/min in group 4. With regard to dosage, patients with a CLCR above 60 ml/min should receive their standard maintenance dose of carumonam without any changes; patients with a CLCR between 30 and 60 ml/min should receive the dose every 12 h; and individuals with a CLCR between 10 and 30 ml/min should be given the dose once a day. Patients with a CLCR of less than 10 ml/min should receive one-half of the dose once a day. Our recommended dosage regimens should produce within the CLCR borderlines of each group average plasma concentrations that are between one and two times that achieved in normal subjects with a t.i.d. dosage regimen.