Pharmacoeconomic evaluation of antimuscarinic agents for the treatment of overactive bladder.
OBJECTIVE
To compare the cost-effectiveness of various antimuscarinic agents for the treatment of overactive bladder (OAB).


METHODS
A decision-analysis model was developed and included clinical outcomes (i.e., therapy continued or discontinued, treatment success or failure, OAB-induced comorbidities) and costs for drugs and treatment of OAB-induced comorbidities (i.e., urinary tract infections, fractures, depression, and skin infections). Treatment success was defined as complete continence. A systematic MEDLINE literature search from January 1990-January 2006 identified English-language articles concerning the eight antimuscarinic drugs: darifenacin, solifenacin, trospium, immediate-release oxybutynin, extended-release oxybutynin, transdermal oxybutynin, immediate-release tolterodine, and extended-release tolterodine. Probabilities and cost data for these drugs were retrieved from the literature, and drug costs were based on 2005 average wholesale prices. The analysis was constructed from a payer's perspective. The time frame for the model was 3 months.


RESULTS
Expected costs for each patient with OAB ranged from $3373 when treated with solifenacin to $3769 when treated with immediate-release oxybutynin. The average cost/patient with continued and successful treatment was lowest for solifenacin ($6863). Solifenacin dominated all other antimuscarinic agents because they were associated with high costs and low effectiveness. Success rates were the key parameters driving the sensitivity analysis.


CONCLUSIONS
Among various antimuscarinic agents, solifenacin 5 mg had the lowest costs and highest effectiveness in the treatment of OAB.
Ko
Yu
Y
Department of Pharmaceutical Sciences, College of Pharmacy, University of Arizona, Tucson, Arizona 85721-0207, USA. ko@pharmacy.arizona.edu
Malone
Daniel C
DC
Armstrong
Edward P
EP
D003362:Cost-Benefit Analysis; D003661:Decision Support Techniques; D004304:Dosage Forms; D006801:Humans; D018727:Muscarinic Antagonists / Q000008:administration & dosage / Q000191:economics* / Q000627:therapeutic use*; D016896:Treatment Outcome; D053201:Urinary Bladder, Overactive / Q000188:drug therapy*; D014549:Urinary Incontinence / Q000188:drug therapy
D004304:Dosage Forms; D018727:Muscarinic Antagonists