Treatment persistence poses a crucial criterion for therapeutic success. Like in many other chronic diseases, in overactive bladder (OAB) syndrome also, many patients discontinue their treatment for diverse reasons. In order to evaluate the persistence in medication, this paper presents data of propiverine extended release (ER) and trospium chloride immediate release (IR) for three consecutive quarters, thus giving an insight into the probability of treatment discontinuation for these two drugs. Prescription data from German health insurances were analyzed. The frequency of follow-up prescriptions and drop-outs for propiverine ER and trospium chloride IR were compared for treatment-naïve, restarted, and switched patients after treatment initiation (quarter 1) for a period of 9 months (three consecutive calendar quarters). In all analyzed quarters, the percentage of follow-up prescriptions was significantly higher for propiverine ER than for trospium chloride IR. The chance of a follow-up prescription was also significantly higher for propiverine ER than for trospium chloride IR, although, in general, both drugs showed a decrease of follow-up prescriptions over time. This comparison of propiverine ER (once-daily administration) and trospium chloride IR (in a multiple dose administration) in patients with OAB syndrome demonstrates that there are substantial differences in the odds of a follow-up prescription. The longer a patient adheres to a therapeutic treatment plan, the better the chances for improvement of symptoms and having a positive impact on activities of daily living.