Influence of renal function on the pharmacokinetics of diacerein after a single oral dose.

The pharmacokinetics of diacerein (a new anti-inflammatory analgesic antipyretic drug) following a single oral dose of 50 mg was studied in 12 healthy volunteers and two groups of eight patients with mild or severe renal insufficiency. Statistical analysis using a Kruskal-Wallis rank sum test showed a significant difference between the three groups for the following parameters. In severely uraemic patients, median AUC0-infinity was multiplied by a factor of ca 2: 40.5 mg h/l versus 21.3 in healthy subjects, P = 0.04; and t1/2 was prolonged by the same factor: 9.6 h versus 4.3 in the control group, P = 0.003. Apparent drug availability and renal clearance assessed through urinary data decreased with renal failure, respectively: 14.5% and 0.045 l/h versus 35.4% (P = 0.01) and 0.13 l/h (P = 0.008) in healthy subjects. Amounts of glucuro and sulfo conjugates in urine were lower in severely uraemic patients. Intermediate values were observed for mildly uraemic patients. Other parameters: lag-time, Cmax, tmax, Vss/F, urinary glucuro- to sulphoconjugate ratios did not change significantly. Apparent total clearance of rhein was poorly correlated with creatinine clearance and this was related to a decrease of non-renal clearance of rhein in renal insufficiency. It was concluded that, from a pharmacokinetic point of view, a reduction (50%) in the maintenance dosage of diacerein should be considered in severe renal failure.