Darifenacin is an M3 muscarinic receptor blocker used to treat urinary incontinence. It can be found under the brand names Emselex and Enablex. Darifenacin blocks M3 muscarinic acetylcholine receptors, which mediate bladder muscle contractions. This block reduces the urgency to urinate and so it should not be used in people with urinary retention. Darifenacin is a competitive muscarinic receptor antagonist. In vitro studies using human recombinant muscarinic receptor subtypes show that darifenacin has greater affinity for the M3 receptor than for the other known muscarinic receptors (9 and 12-fold greater affinity for M3 compared to M1 and M5, respectively, and 59-fold greater affinity for M3 compared to both M2 and M4). 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. Possible side effects of using derifenacin may include dry mouth, constipation, stomach pain, and weakness.

Darifenacin Pathway References