title: Tolerability of solifenacin and oxybutynin immediate release in older (> 65 years) and younger (≤ 65 years) patients with overactive bladder: sub-analysis from a Canadian, randomized, double-blind study.
abstract: OBJECTIVE
  Overactive bladder (OAB) is a common condition whose prevalence increases with age. Antimuscarinic agents are the pharmacologic treatment of choice, but adverse events such as dry mouth may lead to early discontinuation. The purpose of this analysis was to compare the incidence and severity of dry mouth and other adverse events with solifenacin 5 mg/day and oxybutynin immediate release (IR) 15 mg/day in patients ≤ 65 years and >65 years in the Canadian VECTOR study (VEsicare in Comparison To Oxybutynin for oveRactive bladder patients).
  
  
  METHODS
  VECTOR was a randomized, multicentre, prospective, double-blind, double-dummy study in 132 subjects with ≥ 1 urgency episode per 24 h, with or without urgency incontinence, and ≥ 8 micturitions per 24 h for ≥ 3 months. After a 2-week washout, patients received solifenacin 5 mg once daily or oxybutynin IR 5 mg tid for 8 weeks. For the current post-hoc analysis, adverse events were evaluated in subgroups of patients ≤ 65 years and >65 years, using a full logistic regression model, multinomial logit regression model and reduced model.
  
  
  BACKGROUND
  NCT00431041.
  
  
  RESULTS
  The incidence and severity of dry mouth and other adverse events with solifenacin were similar between younger and older patients. In both age subgroups, solifenacin 5 mg/day was associated with fewer episodes and lower severity of dry mouth, and a lower discontinuation rate, compared with oxybutynin IR 15 mg/day.
  
  
  CONCLUSIONS
  Solifenacin 5 mg/day was better tolerated than oxybutynin IR 15 mg/day in younger (≤ 65 years) and older (> 65 years) subgroups. Solifenacin was equally well tolerated in both age subgroups. Limitations of the analysis were that the study was not preplanned to perform post-hoc subgroup analysis, patients knew that dry mouth was a primary outcome, and the study used fixed doses of each drug.
authors.affiliation: University of Toronto, Department of Surgery/Urology, Toronto, Canada. s.herschorn@utoronto.ca
authors.forename: S
authors.initials: S
authors.lastname: Herschorn
authors.forename: P
authors.initials: P
authors.lastname: Pommerville
authors.forename: L
authors.initials: L
authors.lastname: Stothers
authors.forename: B
authors.initials: B
authors.lastname: Egerdie
authors.forename: J
authors.initials: J
authors.lastname: Gajewski
authors.forename: K
authors.initials: K
authors.lastname: Carlson
authors.forename: S
authors.initials: S
authors.lastname: Radomski
authors.forename: H
authors.initials: H
authors.lastname: Drutz
authors.forename: J
authors.initials: J
authors.lastname: Schulz
authors.forename: J
authors.initials: J
authors.lastname: Barkin
authors.forename: E
authors.initials: E
authors.lastname: Hirshberg
authors.forename: J
authors.initials: J
authors.lastname: Corcos
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002170:Canada; D004304:Dosage Forms; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D015201:Meta-Analysis as Topic; D008875:Middle Aged; D018727:Muscarinic Antagonists / Q000008:administration & dosage / Q000009:adverse effects; D011812:Quinuclidines / Q000008:administration & dosage* / Q000009:adverse effects*; D000069464:Solifenacin Succinate; D044005:Tetrahydroisoquinolines / Q000008:administration & dosage* / Q000009:adverse effects*; D053201:Urinary Bladder, Overactive / Q000188:drug therapy*; D055815:Young Adult
chemical_list: D004304:Dosage Forms; D018727:Muscarinic Antagonists; D011812:Quinuclidines; D044005:Tetrahydroisoquinolines; D000069464:Solifenacin Succinate