Immediate-release oxybutynin versus tolterodine in detrusor overactivity: A population analysis

We evaluated adherence to treatment with immediate-release (IR) oxybutynin (515 patients) and tolterodine (505 patients) for detrusor overactivity thr ough retrospective analysis of a pharmacy claims database. Outcomes include d percentage of patients continuing therapy for 6 months, medication posses sion ratios, and time to discontinuation of therapy The proportion of patie nts continuing therapy for 6 months was statistically superior for tolterod ine (32%) compared with IR oxybutynin (22%, p<0.001). Medication possession ratios were also superior for patients in the tolterodine group (medians 0 .83 and 0.64, ranges 0.11-1.15 and 0.07-1.13, respectively, p<0.001). Oxybu tynin was discontinued significantly earlier (mean 45 days) than tolterodin e (mean 59 days, p<0.001) and was switched to another therapy more commonly than tolterodine (19% and 14%, respectively), Tolterodine was favored over oxybutynin for several measurements of patient adherence. However, less th an one-third of patients continued therapy with either agent for 6 months. The clinical relevance of these differences is unknown.