Safety and tolerability of extended-release oxybutynin once daily in urinary incontinence: combined results from two phase 4 controlled clinical trials.
Early studies of extended-release oxybutynin in patients with overactive bladder used adjusted-dose regimens ranging from 5 to 30 mg/day to achieve an optimal balance of efficacy and tolerability. The safety and tolerability of extended-release oxybutynin at a fixed dose of 10 mg once daily (commonly prescribed in clinical practice) is reported using pooled data from 2 multicenter, randomized, double-blind, parallel-group trials with a similar study design. One study compared extended-release oxybutynin with immediate-release tolterodine 2 mg bid. The other study compared extended-release oxybutynin with extended-release tolterodine 4 mg qd. In total, 576 patients received extended-release oxybutynin, 399 received extended-release tolterodine, and 193 received immediate-release tolterodine. The incidence of adverse events (AEs) was similar in the three treatment groups (extended-release oxybutynin, 70%; extended-release tolterodine, 64%; and immediate-release tolterodine, 79%). The most common adverse event was dry mouth (extended-release oxybutynin, 29%; extended-release tolterodine, 22%; and immediate-release tolterodine, 33%). Other AEs occurring in more than 5% of patients in any treatment group included constipation, diarrhea, headache, urinary tract infection, pain, dyspepsia, and peripheral edema, with no apparent difference across treatment groups. Most AEs (>90%) were mild or moderate in intensity in all treatment groups. The proportion of patients who discontinued study medication due to AEs was 6.1, 4.8, and 7.8% in the extended-release oxybutynin, extended-release tolterodine, and immediate-release tolterodine groups, respectively. In total, 1.2, 1.0, and 1.6% of patients in the extended-release oxybutynin, extended-release tolterodine, and immediate-release tolterodine groups, respectively, discontinued study medication due to dry mouth.
Armstrong
Robert B
RB
Ortho-McNeil Neurologics, Inc., 1125 Trenton-Harbourton Road, Titusville, NJ 08560-0200, USA. rarmstro@ompus.jnj.com
Dmochowski
Roger R
RR
Sand
Peter K
PK
Macdiarmid
Scott
S
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001559:Benzhydryl Compounds / Q000008:administration & dosage* / Q000009:adverse effects*; D003408:Cresols / Q000008:administration & dosage* / Q000009:adverse effects*; D003692:Delayed-Action Preparations; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008333:Mandelic Acids / Q000008:administration & dosage* / Q000009:adverse effects*; D008875:Middle Aged; D018727:Muscarinic Antagonists / Q000008:administration & dosage* / Q000009:adverse effects*; D010665:Phenylpropanolamine / Q000008:administration & dosage* / Q000009:adverse effects*; D011446:Prospective Studies; D000068737:Tolterodine Tartrate; D016896:Treatment Outcome; D014549:Urinary Incontinence / Q000188:drug therapy*
D001559:Benzhydryl Compounds; D003408:Cresols; D003692:Delayed-Action Preparations; D008333:Mandelic Acids; D018727:Muscarinic Antagonists; D010665:Phenylpropanolamine; D000068737:Tolterodine Tartrate; C005419:oxybutynin