Single and repeated dose pharmacokinetics of dexketoprofen trometamol in patients with impaired liver function

Dexketoprofen trometamol, a high water-soluble salt of the active enantiomer of rac-ketoprofen, is a nonsteroidal antiinflammatory drug (NSAID) used for pain relief. This study compared the pharmacokinetics of dexketoprofen in patients with impaired liver function and normal subjects following single and repeated oral dosing. Subjects with normal liver function (n = 6) and with Child-Pugh A (n = 7) or Child-Pugh B (n = 5) hepatic impairment scores completed this open-label and parallel study. They received 25 mg dexketoprofen (equivalent to 37 mg of its tromethamine salt) as a single (day 1) and a 3-day repeated dose (1 dose every 8 hours for a total of 10 doses). Dexketoprofen concentrations were determined in plasma and urine by reverse-phase high performance liquid chromatography (HPLC). Model-independent pharmacokinetic parameters were obtained. All subjects completed the study. No serious adverse events were recorded. Following the single dose, mean (+/- SEM) Cmax were 3027.7 +/- 429.3 ng/ml (healthy subjects), 2856.3 +/- 340.3 ng/ml (Child-Pugh A) and 1937.2 +/- 328.0 ng/ml (Child-Pugh B). Median tmax were 0.49 h (0.33-0.68) h, 0.50 h (0.33-0.67) h and 0.67 h (0.33-1.50) h. AUC0-x averaged 3778.0 +/- 439.0 ng.h/ml, 4890.4 +/- 539.1 ng.h/ml and 3985.0 +/- 712.0 ng.h/ml. Mean CL/F were 101.1 +/- 11.3 ml/h/kg, 73.3 +/- 9.9 ml/h/kg and 88.8 +/- 15.5 ml/h/kg and V/F averaged 0.192 +/- 0.018 l/kg, 0.162 +/- 0.006 l/kg and 0.214 +/- 0.044 l/kg. Following the repeated administration, similar results were obtained showing no drug accumulation. As related to the administered dose, median excretions of unchanged and conjugated dexketoprofen in urine were 2.1% and 67.1% in healthy subjects, 2.8% and 60.9% in Child-Pugh A subjects and 4.4% and 47.7% in Child-Pugh B volunteers. A trend towards a reduced urinary excretion of conjugated dexketoprofen in hepatic patients, more evident in the Child-Pugh B than in the Child-Pugh A groups, was observed when compared with healthy volunteers (median and 95% CI for differences: -5.4% [-19.9% to 2.0%] and -19.4% [-45.6% to 0.4%]). Conservatively, a dose adjustment of dexketoprofen trometamol in patients with impaired hepatic function is recommended.