Tolterodine is an antimuscarinic drug that is used to treat urinary incontinence. Tolterodine acts on M2 and M3 subtypes of muscarinic receptors.
Indication
For the treatment of overactive bladder (with symptoms of urinary frequency, urgency, or urge incontinence).
Pharmacology
Tolterodine is a competitive muscarinic receptor antagonist. Both urinary bladder contraction and salivation are mediated via cholinergic muscarinic receptors. After oral administration, tolterodine is metabolized in the liver, resulting in the formation of the 5-hydroxymethyl derivative, a major pharmacologically active metabolite. The 5-hydroxymethyl metabolite, which exhibits an antimuscarinic activity similar to that of tolterodine, contributes significantly to the therapeutic effect. Both tolterodine and the 5-hydroxymethyl metabolite exhibit a high specificity for muscarinic receptors, since both show negligible activity or affinity for other neurotransmitter receptors and other potential cellular targets, such as calcium channels. Tolterodine has a pronounced effect on bladder function. The main effects of tolterodine are an increase in residual urine, reflecting an incomplete emptying of the bladder, and a decrease in detrusor pressure, consistent with an antimuscarinic action on the lower urinary tract.
Affected Organisms
Humans and other mammals
Half Life
1.9-3.7 hours
Protein Binding
Approximately 96.3%.
Elimination
Following administration of a 5-mg oral dose of 14C-tolterodine solution to healthy volunteers, 77% of radioactivity was recovered in urine and 17% was recovered in feces in 7 days.
