Critical Evaluation of the Efficacy and Safety of Anticholinergics in Overactive Bladder

Abstract

Antimuscarinic agents are the primary pharmacologic treatment of overactive bladder (OAB), and objective clinical data are available in a range of formats including head-to-head studies, systematic reviews and adjusted indirect comparisons. This paper reexamines the various data available on the safety and efficacy of the antimuscarinics. Clinical studies determine whether one treatment is better than another, rather than examining which treatment is best for the individual patient. Favourable treatment outcome may not be attained because of unrealistic expectations of the patient, who may also be dissatisfied with the complications of the treatment. Comparisons between clinical studies on drug therapy for OAB may be complicated by the high placebo response rates. Variations exist in the study populations in terms of symptom severity and tolerance of adverse events, and the diverse methods of assessment employed. Apart from head-to-head studies, meta-analyses can be employed to compare different classes of drugs (lumping method) or individual drugs (splitting method) by pooling of clinical data. The adjusted indirect comparison method has been developed as a method to allow the outcome of two different trials to be compared. Overall, data from clinical trials indicate that the commonly used antimuscarinics have different tolerability and safety profiles but broadly similar efficacy profiles. Consequently, therapy should be tailored to individual patient needs rather than one drug fits all.