Examples:
oxybutynin, tolterodine, fesoterodine, trospium, darifenacin, solifenacin
Mechanism:
Via anticholinergic action, increasing muscle tone at the bladder to inhibit voiding
Dosing:
oxybutynin, trospium, tolterodine: once to twice daily
other agents (and extended release versions): once daily
*trospium is on an empty stomach
Adverse Effects: (Anticholinergic toxicity)
blurred vision (pupil dilation)
dry mouth - use mouth moisturizers
confusion - caution in elderly
constipation
dizziness
drowsiness
tachycardia
adverse effects may be mitigated by choosing extended release versions or oxybutynin patch
Drug Interactions:
-CYP 3A4 inhibitors: caution with many of these agents
-CYP 2D6 inhibitors: caution with darifenacin and fesoterodine
-caution with other anticholinergic and CNS depressants