hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.tinidazoleMonitor Closely (1)darifenacin will increase the level or effect of tinidazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.tiotropiumMonitor Closely (1)darifenacin and tiotropium both decrease cholinergic effects/transmission. Use Caution/Monitor.tipranavirMonitor Closely (2)darifenacin will increase the level or effect of tipranavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. tipranavir will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.tolterodineMonitor Closely (2)darifenacin will increase the level or effect of tolterodine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. darifenacin and tolterodine both decrease cholinergic effects/transmission. Use Caution/Monitor.Minor (1)darifenacin will increase the level or effect of tolterodine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.tolvaptanSerious - Use Alternative (1)darifenacin will increase the level or effect of tolvaptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.topiramateMonitor Closely (1)topiramate will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.tramadolMinor (1)darifenacin will increase the level or effect of tramadol by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.trazodoneMonitor Closely (1)darifenacin will increase the level or effect of trazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Minor (1)darifenacin and trazodone both decrease cholinergic effects/transmission. Minor/Significance Unknown.triamcinolone acetonide injectable suspensionMonitor Closely (1)darifenacin will increase the level or effect of triamcinolone acetonide injectable suspension by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.triazolamMonitor Closely (1)darifenacin will increase the level or effect of triazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.trifluoperazineMonitor Closely (3)darifenacin decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. darifenacin decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor. trifluoperazine increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Minor (1)darifenacin will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.trihexyphenidylMonitor Closely (1)darifenacin and trihexyphenidyl both decrease cholinergic effects/transmission. Use Caution/Monitor. Potential for additive anticholinergic effects.trimipramineMonitor Closely (1)darifenacin and trimipramine both decrease cholinergic effects/transmission. Use Caution/Monitor.tropisetronMinor (1)darifenacin will increase the level or effect of tropisetron by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.trospium chlorideMonitor Closely (1)darifenacin and trospium chloride both decrease cholinergic effects/transmission. Use Caution/Monitor.tucatinibSerious - Use Alternative (1)tucatinib will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid concomitant use of tucatinib with CYP3A substrates, where minimal concentration changes may lead to serious or life-threatening toxicities. If unavoidable, reduce CYP3A substrate dose according to product labeling.umeclidinium bromide/vilanterol inhaledSerious - Use Alternative (1)darifenacin, umeclidinium bromide/vilanterol inhaled. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Concomitant use with other anticholinergic-containing drugs may lead to additive anticholinergic adverse effects.vardenafilMonitor Closely (1)darifenacin will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.vecuroniumMonitor Closely (1)darifenacin and vecuronium both decrease cholinergic effects/transmission. Use Caution/Monitor.verapamilMonitor Closely (2)darifenacin will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. verapamil will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.vinblastineMinor (1)darifenacin will increase the level or effect of vinblastine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.vincristineMinor (1)darifenacin will increase the level or effect of vincristine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.vincristine liposomalMinor (1)darifenacin will increase the level or effect of vincristine liposomal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.vinorelbineMinor (1)darifenacin will increase the level or effect of vinorelbine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.voriconazoleMonitor Closely (1)voriconazole will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.voxelotorSerious - Use Alternative (1)voxelotor will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Voxelotor increases systemic exposure of sensitive CYP3A4 substrates. Avoid coadministration with sensitive CYP3A4 substrates with a narrow therapeutic index. Consider dose reduction of the sensitive CYP3A4 substrate(s) if unable to avoid.zafirlukastMonitor Closely (1)zafirlukast will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.zaleplonMinor (1)darifenacin will increase the level or effect of zaleplon by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.ziprasidoneMonitor Closely (3)darifenacin decreases levels of ziprasidone by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. darifenacin decreases levels of ziprasidone by pharmacodynamic antagonism. Use Caution/Monitor. ziprasidone increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Minor (1)darifenacin will increase the level or effect of ziprasidone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.zolpidemMinor (1)darifenacin will increase the level or effect of zolpidem by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.zonisamideMinor (1)darifenacin will increase the level or effect of zonisamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.zotepineMonitor Closely (2)darifenacin decreases levels of zotepine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. darifenacin decreases levels of zotepine by pharmacodynamic antagonism. Use Caution/Monitor. >10% Dry mouth (19-35%) Constipation (15-21%) 1-10% Abdominal pain (2-4%) Dizziness (2%) Dry eyes (2%) Dyspepsia (3-8%) Nausea (2-4%) UTI (4-5%) Vaginitis (>1%) Back pain (>1%) Rhinitis (>1%) Abnormal vision (>2%) Vomiting (>1%) Weight gain (>1%) Flu-like syndrome (1-3%) Peripheral edema (>1%) Postmarketing Reports Dermatologic: Erythema multiforme, interstitial granuloma annulare General: Hypersensitivity reactions, including angioedema with airway obstruction and anaphylactic reaction; hallucinations Cardiovascular: Palpitations Contraindications Urinary retention Gastric retention Uncontrolled narrow-angle glaucoma Hypersensitivity Cautions Heat prostration may occur in the presence of increased environmental temperature Use caution in patients with decreased GI motility, hiatal hernia, reflux esophagitis, and ulcerative colitis Administer with caution to patients with clinically significant bladder outflow, obstruction because of the risk of urinary retention Administer with caution to patients with gastrointestinal obstructive disorders because of risk of gastric retention; like other anticholinergic drugs, this drug may decrease gastrointestinal motility and should be used with caution in patients with conditions such as severe constipation, ulcerative colitis, and myasthenia gravis Use with caution in patients being treated for narrow-angle glaucoma and only where potential benefits outweigh risk Angioedema of face, lips, tongue, and/or larynx reported; in some cases angioedema occurred after first dose; angioedema associated with upper airway swelling may be life-threatening; if involvement of the tongue, hypopharynx, or larynx occurs, promptly discontinue therapy and provide appropriate therapy and/or measures necessary to ensure a patent airway The daily dose should not exceed 7.5 mg for patients with moderate hepatic impairment (Child-Pugh B); therapy has not been studied in patients with severe hepatic impairment (Child-Pugh C) and therefore is not recommended for use in this patient population Central nervous system effects Therapy is associated with anticholinergic central nervous system (CNS) effects; a variety of CNS anticholinergic effects have been reported, including headache, confusion, hallucinations, and somnolence Patients should be monitored for signs of anticholinergic CNS effects, particularly after beginning treatment or increasing dose Advise patients not to drive or operate heavy machinery until they know how therapy affects them; if a patient experiences anticholinergic CNS effects, consider dose reduction or drug discontinuation Pregnancy There are no available data on use in pregnant women to evaluate for a drug-associated risk of major birth defects, miscarriage, or other adverse maternal or fetal outcomes Animal data In animal studies, the drug was not teratogenic in rats and rabbits at plasma exposures of free drug (via AUC) up to 59 and 28 times the maximum recommended human dose (MRHD) of 15 mg, respectively Effects on embryofetal development were observed following administration of the drug during pregnancy, including dilated ureter and/or kidney pelvis in rabbits at about 9 times the MRHD, post-implantation loss in rabbits at about 28 times, and delayed ossification in rats at about 59 times During pregnancy and lactation (developmental delays in rats at about 17 times the MRHD), which was associated with maternal toxicity reported Dystocia was observed in rat dams at about 17 times the MRHD Lactation There are no data on presence of drug in human milk, effects on breastfed infant, or on milk production The drug is present in rat milk; when a drug is present in animal milk, it is likely that the drug will be present in human milk The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for darifenacin and any potential adverse effects on the breastfed child from darifenacin or from the underlying maternal conditionsPregnancy Categories A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk. B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available. Mechanism of Action Competitive muscarinic receptor antagonist of the M3 muscarinic receptor; receptor blocking limits bladder contractions, and reduce symptoms of bladder irritability/overactivity Absorption Protein Bound: 98% Vd: 163 L Peak plasma time: 7 hr Metabolism Liver, by CYP3A4 and CYP2D6 Elimination Half-Life: 13-19 hr Excretion: 60% urine; 40% feces BRAND FORM. UNIT PRICE PILL IMAGE darifenacin oral- 15 mg tabletdarifenacin oral- 15 mg tabletdarifenacin oral- 7.5 mg tabletdarifenacin oral- 7.5 mg tabletdarifenacin oral- 15 mg tabletdarifenacin oral- 7.5 mg tabletdarifenacin oral- 7.5 mg tabletCopyright © 2010 First DataBank, Inc.Print Patient Educationdarifenacin oral DARIFENACIN EXTENDED-RELEASE - ORAL (DAR-i-FEN-a-sin) COMMON BRAND NAME(S): Enablex USES: Darifenacin is used to treat an overactive bladder. By relaxing the muscles in the bladder, darifenacin improves your ability to control your urination. It helps to reduce leaking of urine, feelings of needing to urinate right away, and frequent trips to the bathroom. This medication belongs to the class of drugs known as antispasmodics. HOW TO USE: Read the Patient Information Leaflet provided by your pharmacist before you start using darifenacin and each time you get a refill. If you have any questions, ask your doctor or pharmacist.Take this medication by mouth with or without food as directed by your doctor, usually once a day. Swallow this medication with a full glass of water (8 ounces/240 milliliters).Swallow the tablets whole. Do not crush or chew the tablets. Doing so can release all of the drug at once, increasing the risk of side effects.Use this medication regularly to get the most benefit from it. To help you remember, take it at the same time each day.The dosage is based on your medical condition, response to treatment, and other medications you may be taking. Be sure to tell your doctor and pharmacist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).Do not increase your dose or use this drug more often or for longer than prescribed. Your condition will not improve any faster, and your risk of side effects will increase.Tell your doctor if your condition does not improve or if it worsens. SIDE EFFECTS: Dry mouth, constipation, nausea, stomach upset, stomach pain, blurred vision, dry eyes, dizziness, or weakness may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.To relieve dry mouth, suck (sugarless) hard candy or ice chips, chew (sugarless) gum, drink water, or use a saliva substitute.To prevent constipation, eat dietary fiber, drink enough water, and exercise. You may also need to take a laxative. Ask your pharmacist which type of laxative is right for you.Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.Tell your doctor right away if you have any serious side effects, including: severe stomach/abdominal pain, constipation for 3 or more days, difficulty urinating, signs of kidney infection (such as burning/painful/frequent urination, fever, pink/bloody urine), mental/mood changes (such as confusion, hallucinations).Get medical help right away if you have any very serious side effects, including: eye pain/swelling/redness, vision changes (such as seeing rainbows around lights at night).A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat),