Coadministration of Dabigatran Etexilate and Atorvastatin

Abstract

Dabigatran etexilate, a novel oral direct thrombin inhibitor, has been approved for prophylaxis of thromboembolism in patients undergoing total knee or total hip replacement, and is under clinical investigation for treatment of venous thromboembolism, prevention of stroke in patients with atrial fibrillation, and the treatment of thromboembolic complications following acute coronary syndromes. To evaluate the potential impact of atorvastatin coadministration on the pharmacokinetics, pharmacodynamics, and safety of dabigatran etexilate. Healthy male and female volunteers (n = 22) were recruited to this open, randomized, multiple-dose, three-way crossover study. They received dabigatran etexilate 150 mg twice daily on days 1-3 and once daily on day 4, atorvastatin 80 mg once daily on days 1-4, or both treatments together on days 1-4. Exposure to dabigatran at steady state (area under the drug plasma concentration-time curve at steady state) was reduced by 18% with concomitant atorvastatin administration. An 18% increase in plasma atorvastatin concentration occurred with coadministration of dabigatran etexilate. Exposure to its metabolite 2'-hydroxy-atorvastatin remained essentially unchanged and exposure to 4'-hydroxy-atorvastatin was increased by 15%. The small changes observed are deemed of little clinical relevance given the overall inter-individual variability in the metabolism of atorvastatin. Furthermore, there were no changes in the concentrations of active HMG-CoA reductase inhibitors in plasma following dabigatran etexilate coadministration. Six subjects in the atorvastatin treatment group, six subjects during combination treatment, and eight subjects in the dabigatran treatment group reported adverse events. Most of the adverse events reported were nervous system disorders such as dizziness and headache, and general disorders such as fatigue. All adverse events were resolved at the end of the study. Results of this randomized, open-label, three-way crossover design study in healthy male and female volunteers showed that atorvastatin had no influence on the pharmacokinetic/pharmacodynamic profile of dabigatran, and vice versa, dabigatran etexilate had no impact on the pharmacokinetic/pharmacodynamic profile of atorvastatin. Both drugs were well tolerated when given alone or in combination.