Darifenacin

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, reducing the symptoms of overactive bladder.

• 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.

Darifenacin selectively blocks M3 muscarinic receptors, relaxing the detrusor muscle of the bladder, which increases bladder capacity and reduces urinary frequency and urgency.

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.

Take with liquid. May be taken with or without food. Swallow tablet whole, do not chew, divide or crush.

If you miss a dose of Darifenacin, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose. Do not double the dose.

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.

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.

Urinary retention, gastric retention, uncontrolled narrow-angle glaucoma, and patients at risk for these conditions.

CYP3A4 inhibitors (ketoconazole, itraconazole, ritonavir, nelfinavir, clarithromycin, nefazodone): May increase serum levels of Darifenacin; dose should not exceed 7.5 mg/day.

CYP2D6 inhibitors (quinidine, paroxetine): May increase serum levels.

CYP3A4 inducers (barbiturates, phenytoin, rifampicin): May decrease serum concentrations.

Anticholinergic agents: May potentiate side effects.

It is not known whether it is safe to consume alcohol with Darifenacin. Please consult your doctor.

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

It is not known whether Darifenacin is excreted into human milk. Caution should be exercised before administering to a nursing woman.

Safety and effectiveness in pediatric patients have not been established.

No specific dosage adjustment is necessary for elderly patients. However, caution should be exercised.

Renal impairment: Safe to use in patients with kidney disease. No dose adjustment recommended. However, inform your doctor if you have any underlying kidney disease.

Hepatic impairment: Use with caution. Moderate hepatic impairment: maximum 7.5 mg/day. Severe hepatic impairment: Not recommended.

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.

Darifenacin