Overactive bladder drugs and constipation: a meta-analysis of randomized, placebo-controlled trials.

BACKGROUND: Anticholinergic drugs are commonly prescribed for symptomatic treatment of overactive bladder (OAB). While recent meta-analyses have characterized the prevalence of dry mouth among patients utilizing OAB medications, prevalence of constipation has not been systematically reviewed. AIMS: To provide an effect measure for constipation associated with anticholinergic OAB drugs versus placebo. METHODS: A meta-analysis of trials with darifenacin, fesoterodine, oxybutynin, solifenacin, tolterodine, and trospium was conducted. All randomized, placebo-controlled studies of anticholinergic OAB drugs published in English language and identified in Medline and Cochrane databases were considered for inclusion in this meta-analysis. Those meeting predetermined design characteristics and having sufficient duration (≥2 weeks) were included. Constipation-related data from all included studies were abstracted. RESULTS: One hundred two English-language, randomized, placebo-controlled trials were originally identified. Thirty-seven studies were ultimately included in the analysis, involving 19,434 total subjects (12,368 treatment+7,066 placebo patients). The odds ratios for constipation compared with placebo were as follows: overall [odds ratio (OR) 2.18, 95% confidence interval (CI)=1.82-2.60], tolterodine (OR 1.36, 95% CI=1.01-1.85), darifenacin (OR 1.93, 95% CI=1.40-2.66), fesoterodine (OR 2.07, 95% CI=1.28-3.35), oxybutynin (OR 2.34, 95% CI=1.31-4.16), trospium (OR 2.93, 95% CI=2.00-4.28), and solifenacin (OR 3.02, 95% CI=2.37-3.84). CONCLUSIONS: Our results demonstrate that patients prescribed anticholinergic OAB drugs are significantly more likely to experience constipation. Differences in muscarinic receptor affinities among individual agents may possibly account for the modest variation in constipation rates observed; however, such a determination warrants additional research.

First renin inhibitor, aliskiren, for the treatment of hypertension.

AIM OF THE REVIEW: To systematically analyze the efficacy and safety of aliskiren for the treatment of hypertension in comparison to placebo, other monotherapy, and various combination therapies. METHOD: A PubMed database (1966-June 2008) search was conducted with aliskiren as a search term with limits of humans, written in English, and in title only. Phase III pivotal clinical studies retrieved by PubMed database and resources such as printed labeling, approval letter, pharmacology reviews, and medical reviews posted in Drug@FDA website were evaluated with regard to study design and outcomes of efficacy and safety. RESULTS: Six Phase III pivotal clinical studies compared various doses of aliskiren to placebo and some studies compared aliskiren to treatment with other monotherapies or combinations. Aliskiren in doses of 300 mg showed a statistically significant reduction in both systolic and diastolic blood pressure versus placebo. Comparison to other antihypertensive treatments suggest that aliskiren doses of 150 and 300 mg may induce blood pressure changes similar to those seen with moderate doses of hydrochlorothiazide or angiotensin receptor blockers. Aliskiren in combination with angiotensin receptor blockers or hydrochlorothiazide showed additional blood pressure reduction only when higher doses of aliskiren were used. Aliskiren appears to be well tolerated, with diarrhea being the only statistically significant adverse event. CONCLUSION: Aliskiren is a novel antihypertensive that exerts its effects through the direct inhibition of renin. Although the drug is well tolerated, its modest effects on blood pressure and the present lack of evidence of impact on objective cardiovascular outcomes appear to limit its utility in the general treatment of hypertension at this time.