Objective: To provide guidelines for pharmacotherapy to treat overactive bladder syndrome (OAB).
Options: Pharmacotherapy for OAB includes anticholinergic (antimuscarinic) drugs and vaginal estrogen. Both oral and transdermal anticholinergic preparations are available.
Outcomes: To provide understanding of current available evidence concerning safety and clinical efficacy of pharmacotherapy for OAB; to guide selection of anticholinergic therapy based on individual patient characteristics.
Evidence: The Cochrane Library and Medline were searched for articles published from 1950 to the present related to individual anticholinergic drugs. Review articles on management of refractory OAB were also examined. Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. There were no date or language restrictions. Searches were updated on a regular basis and incorporated in the guideline to 2010.
Values: The quality of evidence is rated and recommendations are made using the criteria described by the Canadian Task Force on Preventive Health Care (Table 1).
Benefits, harms, and costs: Anticholinergics are the mainstay of pharmacotherapy for OAB. EVIDENCE for their efficacy is mostly derived from short-term phase III randomized drug trials. Placebo response is strong, and long-term follow-up and patient subjective outcome data are lacking. Care providers need to be well acquainted with the side effects of anticholinergics and select therapy based on individual patient parameters. Recommendations 1. Behavioural management protocols and functional electrical stimulation should be offered in the spectrum of effective primary treatments for overactive bladder syndrome. (I-A) 2. Oral oxybutynin, immediate and extended release, as well as transdermal oxybutynin, may be offered as treatment for overactive bladder syndrome, as they are associated with significant objective clinical improvement at 12 weeks. (I-A) Oxybutynin immediate release has superior cost-effectiveness but more side effects than other anticholinergics. (I-A) Adverse events associated with transdermal oxybutynin are fewer than with oral oxybutynin. (I-A) 3. Tolterodine, immediate and extended release, may be offered as treatment for overactive bladder syndrome, as it is associated with significant objective clinical improvement at 12 weeks. (I-A) 4. Trospium, immediate and extended release, may be offered as treatment for overactive bladder syndrome as it is associated with significant clinical improvement at 12 weeks. (I-A) Trospium is an adequate anticholinergic choice for overactive bladder syndrome patients with pre-existing cognitive impairment (II-B) and for overactive bladder syndrome patients taking concurrent CYP450 inhibitors. (III-B) 5. Solifenacin may be offered as treatment for overactive bladder syndrome, as it is associated with significant objective clinical improvement at 12 weeks. (I-A) Solifenacin may be an adequate anticholinergic choice for elderly overactive bladder syndrome patients or patients with pre-existing cognitive dysfunction. (I-B) 6. Darifenacin may be offered as treatment for overactive bladder syndrome, as it is associated with significant objective clinical improvement at 12 weeks. (I-A) Darifenacin is an adequate anticholinergic choice for overactive bladder syndrome patients with pre-existing cardiac concerns or cognitive dysfunction. (I-B) 7. Overactive bladder syndrome patients should be offered a choice between bladder training, functional electric stimulation, and anticholinergic therapy, as there is no difference in cure rates. Combination therapy does not have a clear advantage over one therapy alone. (I-A) 8. The choice of anticholinergic therapy should be guided by individual patient comorbidities, as objective efficacy of anticholinergic drugs is similar. (I-A) Dose escalation does not improve objective parameters and causes more anticholinergic adverse effects. It is, however, associated with improved subjective outcomes. (I-A) To decrease side effects, switching to a lower dose or using an extended release formulation or a transdermal delivery mechanism should be considered. (I-A) 9. Education on treatment efficacy, realistic expectations, and length of treatment should be offered to patients upon initiation of anticholinergic therapy, as continuation rates for anticholinergic therapy are low. (III-B) 10. Oral or transdermal estrogen supplementation should not be recommended for treatment of overactive bladder syndrome as its effects are comparable to placebo. (I-E) Vaginal estrogen can be suggested for subjective improvements in overactive bladder syndrome symptoms. (III-B) 11. Intravesical botulinum toxin injection and sacral nerve and posterior tibial nerve stimulation are clinically effective options for patients with overactive bladder syndrome unresponsive to conservative options, anticholinergics, or vaginal estrogen. (I-A).