Darif

Uses

Darif is used for the treatment of overactive bladder with symptoms of urge urinary incontinence, urgency and frequency.

Darif is also used to associated treatment for these conditions: Urinary Bladder, Overactive

How Darif works

Darif selectively antagonizes the muscarinic M3 receptor. M3 receptors are involved in contraction of human bladder and gastrointestinal smooth muscle, saliva production, and iris sphincter function.

Dosage

Darif dosage

Darif 7.5 mg once daily; may increase dose to 15 mg once daily if no adequate response after 2 wk of therapy. Darif should be taken with liquid. It can be taken with or without food, and should be swallowed whole and not chewed, divided or crushed.

For patients with moderate hepatic impairment or when co-administered with potent CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, ritonavir, nelfinavir, clarithromycin and nefazadone), the daily dose of Darif should not exceed 7.5 mg.

Side Effects

The most common side effects are dry mouth & constipation. Other less commonly reported side effects include- abnormal vision, back pain, dry skin, hypertension, vomiting, peripheral edema, weight gain, arthralgia, bronchitis, pharyngitis, rhinitis, sinusitis, rash, pruritus, urinary tract disorder and vaginitis.

Toxicity

Overdosage can potentially result in severe central anticholinergic effects.

Precaution

Darif should be used with caution in the patient at risk for urinary retention & decreased gastrointestinal motility, with impaired renal & hepatic impairment.

Interaction

Darif has known drug-drug interaction with CYP3A4 inhibitors (e.g. ketoconazole, itraconazole, ritonavir, nelfinavir etc.). The concomitant use of Darif with other anticholinergic agents may increase the frequency and/or severity of dry mouth, constipation, blurred vision and other anticholinergic pharmacological effects.

Food Interaction

• Take with or without food. The absorption is unaffected by food.

[Minor] The consumption of grapefruit juice may be associated with increased plasma concentrations of darifenacin.

The mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruits.

The clinical significance is unknown.

Darif Drug Interaction

Moderate: metoprolol, metoprolol, mirabegron, mirabegronMinor: acetaminophen, acetaminophenUnknown: aspirin, aspirin, multivitamin with minerals, multivitamin with minerals, warfarin, warfarin, levothyroxine, levothyroxine, vilazodone, vilazodone, cyanocobalamin, cyanocobalamin, cholecalciferol, cholecalciferol

Darif Disease Interaction

Major: gastric retention, glaucoma, urinary retentionModerate: CNS effects, liver disease

Volume of Distribution

• 163 L

Elimination Route

The mean oral bioavailability at steady state is estimated to be 15% and 19% for 7.5 mg and 15 mg tablets, respectively.

Half Life

The elimination half-life of darifenacin following chronic dosing is approximately 13-19 hours.

Clearance

• 40 L/h [extensive metabolizers]
• 32 L/h [poor metabolizers]

Pregnancy & Breastfeeding use

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

Lactation: It is not known whether Darif is excreted into human milk and therefore caution should be exercised before Darif is administered to a nursing woman.

Contraindication

Patient with urinary retention, gastric retention, uncontrolled narrow-angle glaucoma, and in patients who are at risk for these conditions.

Acute Overdose

Overdosage with antimuscarinic agents can result in severe antimuscarinic effects. ECG monitoring is recommended when event of overdosage is occurred. Darif 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.

Storage Condition

Store at 25° C. Protect from light.

Innovators Monograph

You find simplified version here Darif