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WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT• Dabigatran etexilate is an oral prodrug that is rapidly converted to dabigatran, a direct and reversible thrombin inhibitor.• Dabigatran etexilate and dabigatran are not metabolized by the cytochrome P450 system, and dabigatran does not affect the metabolism of other drugs that utilize this system, leading to a low potential for drug-drug interactions.• Dabigatran etexilate, but not dabigatran, is a P-glycoprotein (P-gp) substrate, and the bioavailability of dabigatran may be altered by P-gp inhibitors or inducers. WHAT THIS STUDY ADDS• Administration of rifampicin (a strong P-gp inducer) for 7 days before a single dose of dabigatran etexilate resulted in a significant reduction in the bioavailability of dabigatran compared with administration of dabigatran etexilate alone.• Within 7 days following the cessation of rifampicin administration, the bioavailability of dabigatran returned almost to baseline values.• Rifampicin is not recommended for use with dabigatran etexilate because of the potential for reduced systemic exposure to dabigatran. AIMSThis study examined the effects of the CYP3A/P-glycoprotein inducer, rifampicin, on the pharmacokinetics of dabigatran following oral administration of the prodrug, dabigatran etexilate. METHODSThis was an open-label, fixed-sequence, four-period study in healthy volunteers. Subjects received a single dose of dabigatran etexilate 150 mg on day 1, rifampicin 600 mg once daily on days 2-8, and single doses of dabigatran etexilate on days 9, 16 and 23. RESULTSTwenty-four subjects were treated, of whom 22 received all treatments. Relative to the reference (single dose of dabigatran etexilate alone; treatment A), administration of dabigatran etexilate following 7 days of rifampicin (treatment B) decreased the geometric mean (gMean) area under the concentration-time curve (AUC0-•) and maximal plasma concentration (Cmax) of total dabigatran by 67 and 65.5%, respectively. The time to peak and the terminal half-life were not affected. The gMean ratio for the primary comparison (treatment B vs. treatment A) was 33.0% (90% confidence interval 26.5, 41.2%) for AUC0-• and 34.5% (90% confidence interval 26.9, 44.1%) for Cmax, indicating a significant effect on total dabigatran exposure (total pharmacologically active dabigatran represents the sum of nonconjugated dabigatran and dabigatran glucuronide). After a 7 day (treatment C) or 14 day washout (treatment D), the AUC0-• and Cmax of dabigatran were reduced by 18 and 20%, and by 15 and 20%, respectively, compared with treatment A, which was considered not clinically relevant. The overall safety profile of all treatments was good. CONCLUSIONSAdministration of rifampicin for 7 days resulted in a significant reduction in the bioavailability of dabigatran, which returned almost to baseline after 7 days washout.

Roflumilast is a new phosphodiesterase 4 (PDE4) inhibitor developed by Byk Gulden Pharmaceuticals for the treatment of chronic obstructive pulmonary disease and asthma. A placebo-controlled, randomized, double-blind, two-period crossover study was performed to investigate the safety and efficacy of roflumilast in 16 patients with exercise-induced asthma. The patients received placebo or roflumilast (500 microg/day) for 28 days, each according to the randomly determined treatment sequences roflumilast/placebo and placebo/roflumilast. In both study periods, exercise challenge was performed 1 hour after dosing on days 1, 14, and 28. FEV1 was measured before exercise challenge, immediately after the end of exercise challenge, and then at 1, 3, 5, 7, 9, and 12 minutes after the end of challenge. Blood samples for the determination of lipopolysaccharide (LPS)-stimulated tumor necrosis factor alpha (TNF-alpha) in whole blood ex vivo as a surrogate marker for the inhibition of inflammatory cell activation were taken predose on days 1 and 28. Serial safety measurements were performed during both study periods. Analysis of variance for the crossover design showed a significant superiority of roflumilast over placebo on day 28. The mean percentage fall of FEV1 after exercise was reduced by 41% as compared to placebo (p = 0.021). An improvement of lung function during roflumilast treatment was also observed on days 1 and 14. The median TNF-alpha level decreased by 21% (p = 0.009) during roflumilast treatment but remained essentially constant under placebo. It is concluded that roflumilast is effective in the treatment of exercise-induced asthma. This result was accompanied by a significant reduction of TNF-alpha levels ex vivo. Treatment with roflumilast was safe and well tolerated.

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Lung function improvements with tiotropium Respimat(®) add-on to medium-dose ICS were sustained and similar for once-daily 5 μg and twice-daily 2.5 μg, supporting tiotropium Respimat(®) 5 μg as a once-daily bronchodilator that provides efficacy over the whole 24-h dosing interval in patients with symptomatic asthma. ClinicalTrials.gov identifier: NCT01152450.

These results imply that the two formulations of pantoprazole can be assumed to be equipotent. Hence, the intravenous formulation of pantoprazole could be considered as an alternative route of administration.

The aim of these studies was to compare the efficacy and the safety of tiotropium, delivered via Respimat Soft Mist Inhaler (SMI), a novel multi-dose, propellant-free inhaler, with ipratropium pressurized metered-dose inhaler (pMDI) in chronic obstructive pulmonary disease (COPD) patients. Two identical, 12-week, multi-national, randomized, double-blind, double-dummy, parallel-group, active- and placebo-controlled studies were performed. COPD patients were randomized to treatment with either inhaled tiotropium (5 or 10 microg) via Respimat SMI administered once daily, ipratropium (36 microg) pMDI QID or placebo. The primary endpoint was the mean trough forced expiratory volume in 1s (FEV(1)) response after 12 weeks of treatment. Secondary endpoints included other spirometry measures and rescue medication use. A total of 719 patients were randomized; the majority were male (69%) with a mean pre-bronchodilator FEV(1) (% predicted) of 40.7%. The mean treatment differences between tiotropium 5 and 10 microg and placebo for the primary endpoint (mean trough FEV(1) response at week 12) were 0.118 and 0.149L, respectively (both P<0.0001). Treatment differences between tiotropium 5 and 10 microg and ipratropium were 0.064L (P=0.006) and 0.095L (P<0.0001). The increases in peak FEV(1), FEV(1) AUC((0-6h)) and FVC for both tiotropium doses were statistically superior to placebo (P<0.01) and higher than ipratropium. All active treatments significantly reduced the rescue medication use compared with placebo, but only tiotropium 10 microg was statistically superior to ipratropium (P=0.04). The incidence of adverse events was comparable across groups. In conclusion, tiotropium 5 and 10 microg daily, delivered via Respimat SMI, significantly improved lung function compared with ipratropium pMDI and placebo.

There were no clinically relevant interactions between netupitant and palonosetron, or between NEPA and oral contraceptives. The coadministration of NEPA with inhibitors or inducers of CYP3A4 may require dose adjustments. Treatments were well tolerated.