Evidence Live 2015: Basic and clinical pharmacology of the "uroselective" α blocker tamsulosin: a critical analysis.

Abstract accepted for poster presentation at Evidence Live 2015.

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Introduction

Tamsulosin is one of the most prescribed urological drugs today and it is also available withoutprescription (over the counter) in some countries (e.g., United Kingdom) despite limited evidence supporting their safety and effectiveness.

Objectives

To determine the safety and effectiveness of tamsulosin in humans.

Methods

1. Data sources

Analysis of tamsulosin studies registered at ClinicalTrials.gov and WHO ICTRP.Analysis of tamsulosin publications (clinical trials, observational studies, systematic reviews and meta-analysis): PubMed, Embase, ISI Web of Knowledge, and other databases.

2. Variables

Prospective vs. retrospective registration: time difference between the 1st submission of the study register and start date for the beginning of patient recruitment.

Published vs. unpublished studies.

Results available at registration site.

Types of sponsor: universities, hospitals, NIH, and non-profit organizations.

Conflicts of interests: Dollars for Docs (Propublica.org).

Reporting quality of the studies: CONSORT, STROBE, PRISM.

Analysis of citations: ISI Web of Knowledge

Re-analysis of pharmacokinetic and pharmacodynamic data (IUPHAR).

Results

Less than 25% of tamsulosin studies in humans are published and their overall quality was poor. Non-industry sponsored trials reported more frequently positive results compared to studies funded by industry. Furthermore, non-industry tamsulosin studies had a higher reporting quality, superior study design (i.e., internal validity) and were less cited than their counterpart (i.e., industry sponsoredstudies). Tamsulosin have no clinically significant uroselectivity (i.e., α1A/D receptors) compared to other alpha blockers. Furthermore, there is evidence that this alpha blocker is associated with hypotension in animal models, clinical trials, case-control studies, and case reports (drug interactions). Uroselective α blockers are only available to use in animal models of in vitro pharmacology, these active pharmacological principles do not exist in the drug market today.

Conclusions

Data concerning the effectiveness and safety of tamsulosin does not support their approved indications in humans.

References

http://dx.doi.org/10.1136/bmj.f6492

http://www.bmj.com/content/347/bmj.f6320/rr/698284