Products
Darifenacin is commercially available in the form of sustained-release tablets (Emselex). It has been approved in many countries since 2005.
Structure and properties
Darifenacin (C28H30N2O2, Mr = 426.6 g/mol) is a tertiary amine. It is present in drugs as darifenacin hydrobromide, a white crystalline powder.
Effects
Darifenacin (ATC G04BD10) has parasympatholytic properties. It is a competitive and selective inhibitor of the muscarinic receptor M3, which, along with M2 on the bladder wall muscles, plays an important role in urinary excretion and the pathogenesis of irritable bladder. However, despite bladder selectivity, adverse effects on other organs are also common with darifenacin.
Indications
For the treatment of hyperactive bladder.
Dosage
According to the drug label. The tablets are usually taken once a day, regardless of meals.
Contraindications
- Hypersensitivity
- Urinary retention
- Gastric emptying disorder
- Untreated narrow-angle glaucoma
- Myasthenia gravis
- Severe liver dysfunction
- Severe ulcerative colitis
- Toxic megacolon
- Treatment with potent CYP3A4 inhibitors and potent P-glycoprotein inhibitors.
For complete precautions, see the drug label.
Interactions
Darifenacin is metabolized by CYP3A4 and CYP2D6 and is a substrate of P-glycoprotein. Corresponding drug-drug interactions are possible. Other interactions have been described with digoxin and anticholinergics.
Adverse effects
Adverse effects can be attributed largely to the anticholinergic properties of the drug. The most common adverse effects include dry mouth, constipation, dyspepsia, nausea, abdominal pain, headache, and dry eyes.
