Darifenacin is used to treat overactive bladder (bladder function disorder that causes a sudden or frequent urge to urinate).
This medicine calms and relaxes the bladder. It reduces the number of toilet visits, increases the amount of urine that your bladder can hold and reduced the urge to urinate.
Take Darifenacin exactly as directed by your doctor or according to the instructions on the label. Do not take more or less than instructed by your doctor.
You may take this medicine with or without food. Try to take it at the same time each day.
Darifenacin is available as an extended-release and as prolonged-release tablets.
If you are taking either the extended-release or prolonged-release type of tablet (usually labelled as “ER” or “PR”), swallow it whole with a glass of water. Do not divide, chew or crush the tablet.
The dose of this medicine will be decided by your doctor. Your doctor will advise you on the treatment timeframe depending on your condition and response to the medication.
Darifenacin must be taken regularly for it to be effective. Continue taking this medicine even when you feel better. Do not stop taking it unless instructed by the doctor.
Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and return to your normal dosing schedule.
DO NOT double a dose under any circumstances.
If you often forget to take your medicine, let your doctor and pharmacist know.
Alert your doctor if you have the following conditions:
- urinary retention (inability to completely empty the bladder when urinating)
- gastric retention (a problem in emptying the contents of the stomach)
- uncontrolled narrow-angle glaucoma (increased pressure in the eyes)
- myasthenia gravis (a muscle weakness disorder)
- severe ulcerative colitis (inflammation of the large intestines)
- toxic megacolon (widening of large intestines caused by complications of infection or inflammation)
- severe liver disease
as Darifenacin may not be suitable for you.
Inform your doctor if you have the following conditions:
- autonomic neuropathy (damage of nerves that regulates vital body functions such as heart rate, blood pressure and bowel activities)
- hiatus hernia (a condition when part of the stomach extends through the diaphragm)
- controlled or receiving treatment for narrow-angle glaucoma (increased pressure in the eyes)
- pre-existing heart disease
- heartburn (burning pain in your chest caused by food or acid from your stomach that backs up into your mouth)
- decreased bowel motility e.g. severe constipation
- obstructive bowel problems e.g. pyloric stenosis (narrowing of the stomach outlet)
- obstruction in bladder flow causing difficulty in passing urine or a weak stream of urine
- enlarged prostate gland
- kidney disease
- mild to moderate liver disease
Let your doctor know if you are pregnant or breastfeeding.
Be sure to check with your doctor or pharmacist before giving this medicine to an elderly.
Darifenacin may reduce sweating and may make your body temperature rise. Discuss with your doctor if you frequently need to exercise, participate in any activity or work in a hot environment.
Certain enzymes called CYP2D6 and CYP3A4 are involved in the breakdown of this medicine in the body. Individuals who lack CYP2D6 enzyme activity, known as CYP2D6 poor metabolisers, may experience an increased Darifenacin exposure and blood concentrations though no dosage adjustment has been recommended. If you know you have this gene type, inform your doctor.
Keep your appointments with your doctor. Your doctor needs to monitor your condition and check your response to the medication regularly.
- You may need to have routine liver function tests while you are being treated with this medicine. Your doctor will advise you about how often you will need to have these tests.
- Monitoring for signs and symptoms of brain (e.g. confusion, headache) and visual effects (e.g. blurred vision, dry eyes).
Darifenacin may cause dizziness, drowsiness, or some problems with your eyesight, such as blurred vision. If affected, do not drive or take part in any activity in which you need to be alert or need to see clearly.
Dry mouth and constipation are common side effects of this medicine. If you experience severe dry mouth, take some sweets, mints or chewing gum to help reduce the discomfort. If you experience constipation, drink several glasses of water each day and eat a well-balanced diet.
Other side effects include any of the following: headache, altered taste, mouth ulceration, constipation, stomach pain, nausea, indigestion, difficulty sleeping, weakness, swelling of the ankles, feet or hand, and dryness of the skin, eyes or nose.
If you develop rashes, breathlessness, swollen eyes, face, mouth, tongue or throat, stop taking Darifenacin and inform your doctor immediately. These could be signs of an allergic reaction.
Inform your doctor if any of these side effects do not go away or are severe, or if you experience other side effects.
Inform your doctor and pharmacist if you are taking any of these medicines:
- medicines to treat fungal infection e.g. ketoconazole, itraconazole, terbinafine, fluconazole
- certain medicines for HIV infection e.g. ritonavir, nelfinavir
- ciclosporin (a medicine used in organ transplant or certain immune disorders)
- verapamil (medicine for high blood pressure or heart disease)
- other medicines to treat overactive bladder e.g. tolterodine, oxybutynin, flavoxate
- medicines for heart disease e.g. digoxin, quinidine, flecainide
- medicines for epilepsy (fits or seizures) e.g. carbamazepine, phenobarbital
- medicines to treat depression e.g. imipramine, paroxetine, fluoxetine, nefazodone
- medicines for mood disorder e.g. thioridazine, duloxetine
- certain antibiotics e.g. erythromycin, clarithromycin, telithromycin
- medicines for osteoporosis e.g. alendronic acid, ibandronic acid
- rifampicin (medicine to treat tuberculosis or TB)
- cimetidine (gastric medicine)
- herbal medicine e.g. St. John’s wort
This list does not include all medicines that may interact with Darifenacin.
Always notify your doctor and pharmacist if you are taking any other medicines, including herbal tonics such as traditional Chinese medicines, supplements and medicines that you buy without a prescription.
Avoid excessive consumption of grapefruit or grapefruit juice.
Store in a cool, dry place away from the reach of children. Protect from light.
Medicines must not be used past the expiry date.