Darifen ER

• Overactive bladder (urge urinary incontinence, urgency and frequency)

Darifenacin is a potent, competitive and selective muscarinic receptor antagonist which has greater binding affinity for muscarinic M3 receptors. M3 receptors are involved in the contraction of the detrusor muscle of the bladder, GI smooth muscle, saliva production, and iris sphincter function. Darifenacin may increase volume threshold in patients with involuntary detrusor contraction, thus increase bladder capacity.

Adult: Initial dose 7.5 mg once daily; may increase to 15 mg once daily if no adequate response after 2 weeks.

Moderate hepatic impairment (Child Pugh B): Maximum daily dose 7.5 mg.

Severe hepatic impairment (Child Pugh C): Not recommended.

Common: Dry mouth, constipation, blurred vision, headache, nausea, indigestion.

Other: Abnormal vision, back pain, dry skin, hypertension, vomiting, peripheral edema, weight gain, arthralgia, bronchitis, pharyngitis, rhinitis, sinusitis, rash, pruritus, urinary tract disorder, vaginitis.

Pregnancy Category C. Should be used during pregnancy only if the benefit to the mother outweighs the potential risk to the fetus.

May affect driving ability (dizziness, blurred vision, drowsiness). Use with caution in patients at risk for urinary retention, decreased GI motility, renal and hepatic impairment. For dry mouth, chew sugar-free gum or take small sips of water. Avoid caffeine, alcohol, or carbonated drinks.

Overdosage with antimuscarinic agents can result in severe antimuscarinic effects. ECG monitoring is recommended in case of overdosage. At doses up to 75 mg, signs of overdose were limited to abnormal vision.

Store at 25°C. Protect from light. Keep out of reach of children.