Darifenacin Hydrobromide (3 brand names, 1 dosage form, 1 route)
Available dosage forms: TABLET, EXTENDED RELEASE.
Routes of administration: ORAL.
Brand Names
- DARIFENACIN
- DARIFENACIN HYDROBROMIDE
- ENABLEX
Mechanism of Action
Darifenacin is a competitive muscarinic receptor antagonist. Muscarinic receptors play a role in cholinergically mediated functions, including contractions of the urinary bladder smooth muscle. 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). M3 receptors are involved in contraction of human bladder.
Overdosage
Overdosage with antimuscarinic agents, including darifenacin extended-release tablets, can result in severe antimuscarinic effects. Treatment should be symptomatic and supportive. In the event of overdosage, ECG monitoring is recommended. Darifenacin extended-release tablet has been administered in clinical trials at doses up to 75 mg (five times the maximum therapeutic dose) and signs of overdose were limited to abnormal vision.