Class: Urinary Antispasmodic
Dosage Forms. Tablet: 5 mg; Extended Release Tablet: 5 mg, 10 mg, 15 mg; Syrup: 5 mg/5 mL
Common FDA Label Indication, Dosing, and Titration.
1. Overactive or neurogenic bladder: 5-10 mg po daily, may titrate to 30 mg/d po
Off-Label Uses.
1. Refractory hot flashes, 5 mg po bid
MOA. Oxybutynin is a competitive muscarinic receptor antagonist. Muscarinic receptors play an important role in several major cholinergically mediated functions, including contractions of the urinary bladder smooth muscle and stimulation of salivary secretion.
Drug Characteristics: Oxybutynin
Medication Safety Issues: Oxybutynin
Drug Interactions: Oxybutynin
Adverse Reactions: Oxybutynin
Efficacy Monitoring Parameters. Resolution of clinical signs of incontinence, urinary frequency, urinary urgency.
Toxicity Monitoring Parameters. Seek medical attention if anticholinergic effects (dry mouth, constipation, cognitive impairment, vision changes) are severe; monitor FBG, HR.
Key Patient Counseling Points. This drug may cause anticholinergic effects including constipation, urinary retention, blurred vision, dyspepsia, or xerostomia. Heat prostration (due to decreased sweating) can occur when used in a hot environment.
Clinical Pearls. Patients should be advised to exercise caution in decisions to engage in potentially dangerous activities until the drug’s effects have been determined. May note decline in cognitive function, especially in elderly. Topical products, including a gel and a transdermal patch, are also available.