Influence of domperidone on pharmacokinetics, safety and tolerability of the dopamine agonist rotigotine.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT: Rotigotine transdermal patch is a new non-ergolinic dopamine agonist developed for the treatment of Parkinson's disease and restless legs syndrome. Peripheral dopaminergic side-effects of dopamine agonists such as nausea and vomiting can be prevented by the antiemetic agent domperidone.

WHAT THIS STUDY ADDS: The study results show no evidence for an interaction of domperidone on bioavailability and steady-state pharmacokinetics of transdermal rotigotine. Co-administration of domperidone and rotigotine does not require dose adjustments for rotigotine transdermal patch.

AIMS: To evaluate the influence of the antiemetic agent domperidone on steady-state pharmacokinetics, safety and tolerability of multiple-dose treatment of the transdermally applied non-ergolinic dopamine agonist rotigotine.

METHODS: Sixteen healthy male subjects (mean age 30.3 years) participated in a randomized, two-way crossover clinical trial. Treatment A consisted of transdermal rotigotine patch (2 mg (24 h)(-1), 10 cm(2), total drug content 4.5 mg) applied daily for 4 days, and concomitant oral domperidone (10 mg t.i.d.) for 5 days. For treatment B, subjects received only transdermal rotigotine treatment (daily for 4 days). Pharmacokinetic variables describing systemic exposure and renal elimination of rotigotine and metabolites, and safety and tolerability of the treatment were assessed.

RESULTS: The primary steady-state pharmacokinetic parameters (C(max,ss) and AUC((0-24),ss)) were similar with or without co-administration of domperidone. Geometric mean ratios were close to 1 and respective 90% confidence intervals were within the acceptance range of bioequivalence (0.8, 1.25): C(max,ss) 0.96 (0.86, 1.08) and AUC((0-24),ss) 0.97 (0.87, 1.08). t(max,ss), t(1/2), secondary parameters calculated on days 4/5 after repeated patch application (C(min,ss), C(ave,ss), AUC((0-tz))) and renal elimination for unconjugated rotigotine and its metabolites were also similar with and without comedication of domperidone. A reduction in the dopaminergic side-effect nausea was seen with domperidone comedication.

CONCLUSIONS: No changes of pharmacokinetic parameters describing systemic exposure and renal elimination of rotigotine were observed when domperidone was administered concomitantly with rotigotine. The lack of pharmacokinetic interactions indicates that a dose adjustment of rotigotine transdermal patch is not necessary with concomitant use of domperidone.