title: Pharmacokinetics and pharmacodynamics of once-daily controlled-release oxybutynin and immediate-release oxybutynin.
abstract: Oxybutynin is used to treat patients with urinary urgency, frequency, and urge incontinence. In this 2-way, multiple-dose, crossover study, the pharmacokinetics and pharmacodynamics of once-daily controlled-release oxybutynin were compared with immediate-release oxybutynin. Eighteen healthy male volunteers received one 15-mg controlled-release oxybutynin tablet once daily for 5 days or one 5-mg immediate-release oxybutynin tablet every 8 hours for 5 days. The washout period between treatments was > or =7 days. The mean steady-state AUC for oxybutynin following controlled-release oxybutynin treatment was higher (73.0 ng.h/mL) than following immediate-release oxybutynin treatment (53.6 ng.h/mL) (P = .0001). The mean C(max) was lower for controlled-release oxybutynin (5.7 ng/mL) than for immediate-release oxybutynin (7.5 ng/mL) (P = .0051), with a smaller fluctuation in oxybutynin plasma concentration for controlled-release oxybutynin (135.6%) than for immediate-release oxybutynin (319.3%) (P = .0001). Mean stimulated saliva output was greater for controlled-release oxybutynin, and mean dry mouth severity was less than immediate-release oxybutynin.
authors.affiliation: Department of Scientific Affairs, Purdue Pharma (Canada), 575 Granite Court, Pickering, Ontario, Canada, L1W 3W8. Joseph.Reiz@purdue.ca
authors.forename: Joseph L
authors.initials: JL
authors.lastname: Reiz
authors.forename: Paulette
authors.initials: P
authors.lastname: Salem
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Darke
mesh_terms: D000293:Adolescent; D000328:Adult; D019540:Area Under Curve; D018592:Cross-Over Studies; D003692:Delayed-Action Preparations / Q000008:administration & dosage / Q000009:adverse effects / Q000493:pharmacokinetics*; D004244:Dizziness / Q000139:chemically induced; D006261:Headache / Q000139:chemically induced; D006801:Humans; D008297:Male; D008333:Mandelic Acids / Q000008:administration & dosage / Q000009:adverse effects / Q000378:metabolism / Q000493:pharmacokinetics*; D008875:Middle Aged; D018727:Muscarinic Antagonists / Q000008:administration & dosage / Q000009:adverse effects / Q000493:pharmacokinetics; D009325:Nausea / Q000139:chemically induced; D010276:Parasympatholytics / Q000008:administration & dosage / Q000009:adverse effects / Q000493:pharmacokinetics; D012044:Regression Analysis; D012472:Salivation / Q000187:drug effects; D013607:Tablets; D013997:Time Factors; D014987:Xerostomia / Q000139:chemically induced
chemical_list: D003692:Delayed-Action Preparations; D008333:Mandelic Acids; D018727:Muscarinic Antagonists; D010276:Parasympatholytics; D013607:Tablets; C032681:desethyloxybutynin; C005419:oxybutynin