THE EFFECTS OF AGE AND GENDER ON THE PHARMACOKINETICS OF TENIDAP SODIUM IN PATIENTS WITH RHEUMATOID-ARTHRITIS AND OSTEOARTHRITIS

1 This open-label study was conducted to evaluate the effects of age a nd gender on the pharmacokinetics of tenidap sodium in patients with e ither rheumatoid arthritis (RA) or osteoarthritis (OA). 2 A total of 1 45 male and female patients, 80 with RA (aged 22-91 years) and 65 with OA (aged 45-83 years) each received a single dose of 120 mg tenidap s odium. Pharmacokinetic parameters were estimated from individual tenid ap plasma concentration-time curves determined up to 120 h post-dose. Tenidap plasma protein binding was determined in the youngest and olde st age groups for both RA and OA patients. 3 In RA patients, age and g ender did not significantly affect the disposition of tenidap or the p ercentage of unbound tenidap in plasma. Only for t(max) were statistic ally significant effects in the analysis of covariance observed and th ese were attributed to very high t(max) values in two female patients. Likewise, in patients with OA, age and gender did not significantly a ffect the pharmacokinetics of tenidap, although patients with larger b ody weights had lower C-max values. 4 Pharmacokinetic parameters were not significantly different between RA and OA patients, except for t(1 /2) where two outlier RA patients had low values that caused the mean value to be significantly lower in RA (24 h) than in OA (26 h) patient s. Pharmacokinetic parameters for pooled values from RA and OA patient s were as follows t(1/2) = 25 h, AUC = 538.4 mu g ml(-1) h, C-max = 21 .9 mu g ml(-1), t(max) = 3.2 h. The value of C-max decreased with incr easing body weight in the combined RA and OA patient group. 5 Four pat ients with RA and six with OA experienced treatment-related side-effec ts. In all but one case of severe headache, side-effects were of mild to moderate severity. Abnormal laboratory test results related to teni dap occurred in six and seven RA and OA patients, respectively. None w as considered severe. 6 This study showed that the pharmacokinetics of tenidap sodium in RA and OA were not significantly affected by age, g ender or disease. Plasma protein binding was not affected by age or ge nder, and was similar in the two diseases. Where statistically signifi cant differences occurred in the covariance analysis of pharmacokineti c parameters, they were not considered clinically meaningful.