Prescription medication · Anticholinergic (Overactive Bladder)
darifenacin
Also sold as Enablex. This medicine treats overactive bladder.
- 596
- FDA reportsRarely reported
- 18
- InteractionsSeveral interactions
- $0.49
- Generic price (NADAC)
What the data shows
darifenacin (Enablex) is a prescription Anticholinergic (Overactive Bladder), among the least-reported drugs the FDA tracks (596 FDA reports), with 18 documented drug interactions.
Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.
darifenacin (Enablex) is a prescription Anticholinergic (Overactive Bladder). This medicine treats overactive bladder.
Darifenacin (Enablex) is a medicine that helps control an overactive bladder. It reduces the feeling of needing to go to the bathroom so often.
Verify with FDA → · CMS NADAC pricing →
Drug Pricing (NADAC)
Generic Price
$0.49/unit
Generic Available
Yes (6 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
What it does
This medicine treats overactive bladder.
Common side effects
Dry mouth, Constipation, Headache
Key warnings
If you have bladder problems that cause you to have trouble urinating, use darifenacin with caution because it could make it harder to urinate.
The sections below are summarized in plain English from darifenacin's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.
How It Works
Darifenacin blocks certain receptors in the bladder. These receptors cause the bladder muscles to contract. By blocking them, the medicine helps the bladder relax and hold more urine.
How to Take It
Take darifenacin once a day with water. You can take it with or without food. Swallow the tablet whole; do not chew, crush, or divide it. You may start with 7.5 mg daily, and your doctor may increase it to 15 mg daily after two weeks.
This is a plain-language summary of darifenacin's FDA labeling, not individualized dosing advice. Ask a pharmacist or prescriber before changing how you take this medication.
Pregnancy & Breastfeeding
Tell your doctor if you are pregnant or plan to become pregnant. It is not known if darifenacin will harm your unborn baby. Talk to your doctor if you are breastfeeding or plan to breastfeed, as it is not known if darifenacin passes into breast milk.
This is a plain-language summary of darifenacin's FDA labeling, not individualized advice. Ask a pharmacist or prescriber about pregnancy or breastfeeding on this medication.
Missed Dose
If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and continue with your regular schedule.
This is a plain-language summary of darifenacin's FDA labeling, not individualized advice. Ask a pharmacist or prescriber what to do about your specific missed dose.
Storage
Store darifenacin at room temperature (68° to 77°F) and protect it from light. Keep out of reach of children.
Side Effects (from patient reports)
Based on 596 FDA adverse event reports.
Most-reported reactions
Adverse reactions in FAERS for darifenacin, by number of reports
- Swelling in the hands, feet, or ankles
Swelling in the hands, feet, or ankles
91 reports
- Shingles
Shingles
83 reports
- Viral pneumonia
Viral pneumonia
79 reports
- Low red blood cell count
Low red blood cell count
59 reports
- Joint pain
Joint pain
59 reports
- Mouth pain
Mouth pain
57 reports
- Joint inflammation
Joint inflammation
56 reports
- High cholesterol
High cholesterol
54 reports
- Abnormal liver test
Abnormal liver test
54 reports
- Inflammation of the joint lining
Inflammation of the joint lining
54 reports
What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.
Reports over time
Adverse-event reports filed for darifenacin each year to the FDA Adverse Event Reporting System (FAERS).
Year-to-year volume tracks usage, prescribing, and scrutiny, not a change in per-patient risk. Source: FDA FAERS.
Where darifenacin sits
darifenacin has more FDA adverse-event reports than 4% of the drugs FAERS tracks. A high position reflects how widely a drug is used and watched, not how dangerous it is.
Percentile across all drugs PlainMeds tracks by FAERS report volume. The dot is darifenacin; the line is the median (50th percentile).
FDA Adverse Event Report Analysis
Detailed analysis of 596 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2005–2025.
Total Reports
596
Reports Mentioning Death
56
9.4% of reports — not proof of cause
Hospitalization Reports
174
Top Indication
Product Used For Unknown Indication
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 2 | PERIPHERAL SWELLING | 91 |
| 3 | HERPES ZOSTER | 83 |
| 4 | PNEUMONIA VIRAL | 79 |
| 5 | ANAEMIA | 59 |
| 6 | ARTHRALGIA | 59 |
| 7 | ORAL PAIN | 57 |
| 8 | ARTHRITIS | 56 |
| 9 | BLOOD CHOLESTEROL INCREASED | 54 |
| 10 | LIVER FUNCTION TEST ABNORMAL | 54 |
| 11 | SYNOVITIS | 54 |
| 12 | LEUKOPENIA | 53 |
| 13 | FIBROMYALGIA | 52 |
| 14 | INFECTION | 51 |
| 15 | JOINT SWELLING | 49 |
| 17 | SOFT TISSUE DISORDER | 41 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation
Serious Warnings
If you have bladder problems that cause you to have trouble urinating, use darifenacin with caution because it could make it harder to urinate. Use caution if you have stomach or bowel blockage, as this medicine can make it worse. Darifenacin may cause sleepiness, so do not drive or operate heavy machinery until you know how it affects you. Angioedema (swelling of the face, lips, tongue, and/or throat) has been reported with darifenacin and can be life-threatening.
Known Drug Interactions
7 DRUG INTERACTIONS Caution should be taken when darifenacin extended-release tablets are used concomitantly with medications that are predominantly metabolized by CYP2D6 and which have a narrow therapeutic window, such as flecainide, thioridazine and tricyclic antidepressants ( 7.2 ) The concomitant use of darifenacin extended-release tablets with other anticholinergic agents may increase the frequency and/or severity of dry mouth, constipation, blurred vision and other anticholinergic pharmacological effects. 7.3 CYP2D6 Substrates Caution should be taken when darifenacin extended-release...
Mechanism: Darifenacin can slow down the way your body breaks down thioridazine. This can cause thioridazine to build up to unsafe levels in your blood, which may lead to dangerous side effects.
What to do: Use this combination with caution. Your doctor may need to adjust your dosage or monitor you more frequently for side effects.
7 DRUG INTERACTIONS Caution should be taken when darifenacin extended-release tablets are used concomitantly with medications that are predominantly metabolized by CYP2D6 and which have a narrow therapeutic window, such as flecainide, thioridazine and tricyclic antidepressants ( 7.2 ) The concomitant use of darifenacin extended-release tablets with other anticholinergic agents may increase the frequency and/or severity of dry mouth, constipation, blurred vision and other anticholinergic pharmacological effects. 7.3 CYP2D6 Substrates Caution should be taken when darifenacin extended-release...
Mechanism: Darifenacin interferes with the enzyme that clears flecainide from your system. This can cause the heart medicine to reach high levels in your body that could be toxic.
What to do: Your doctor should use caution when prescribing these together. They may need to monitor your heart rhythm or adjust your medication dose.
Darifenacin Vardenafil Not recommended during and 2 weeks after itraconazole treatment.
Mechanism: Itraconazole interferes with the enzymes that remove darifenacin from your body, leading to higher levels of the drug in your blood. This increase can make you more likely to experience side effects.
What to do: You should not use these two medicines at the same time or for two weeks after you finish taking itraconazole.
7.2 CYP2D6 Inhibitors No dosing adjustments are recommended in the presence of CYP2D6 inhibitors (for example, paroxetine, fluoxetine, quinidine and duloxetine) [see Clinical Pharmacology (12.3) ] .
Mechanism: Fluoxetine slows down the liver's ability to break down darifenacin. This might cause a small increase in the amount of darifenacin in your system.
What to do: No dose changes are needed when taking these medicines together.
7.2 CYP2D6 Inhibitors No dosing adjustments are recommended in the presence of CYP2D6 inhibitors (for example, paroxetine, fluoxetine, quinidine and duloxetine) [see Clinical Pharmacology (12.3) ] .
Mechanism: Duloxetine blocks a specific liver protein that helps clear darifenacin from the body. This can lead to slightly higher levels of darifenacin.
What to do: You can safely take these medications together without adjusting your dosage.
This is a plain-language summary of interactions documented in FDA labeling, not individualized advice. Ask a pharmacist or prescriber before combining medications.
Common Questions
Can I cut the tablet in half?
What if I have glaucoma?
Can I drink alcohol while taking this medicine?
What should I do if I get a headache?
Can this medicine cause constipation?
What if I am taking other medications?
How long does it take for this medicine to work?
Can I drive while taking this medicine?
What if I have liver problems?
Can I take this with other anticholinergic medicines?
What are the common side effects of darifenacin?
Does darifenacin interact with other medications?
What drug class is darifenacin?
Is darifenacin safe during pregnancy?
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dutasteride/tamsulosin
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Medication Guides
Understanding Drug Interactions
How CYP450 enzymes, inhibitors, and inducers affect your medications
Generic vs Brand Name Drugs
FDA requirements, cost savings, and when the difference matters
Narrow Therapeutic Index Drugs
Why some drugs demand precise dosing and monitoring
Common Drug Interactions
Dangerous medication combinations and how to protect yourself
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What the FDA Data Shows for darifenacin
The FDA label for darifenacin (sold under brand names such as Enablex) classifies it as a prescription-only medication in the Anticholinergic (Overactive Bladder) class. This medicine treats overactive bladder. Official labeling lists 8 commonly reported side effects, including Dry mouth, Constipation, Headache.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 596 voluntary reports. The database also lists 18 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated moderate severity. NADAC pricing from CMS shows a generic unit cost of $0.49.
Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history, and patent information further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice, always consult a licensed healthcare provider before starting, stopping, or changing any medication.
Data Sources
Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC).
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. Always consult a healthcare professional before making medication decisions.
Last updated: April 19, 2024
Read our methodology - how this data is sourced, computed, and verified.
Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled and last refreshed May 2026. See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a correction.
All federal data sources used on this page
- FDA Orange Book - approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed - NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) - post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm - standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files - federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database - current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages