Prescription medication · Anticholinergic (Overactive Bladder)
darifenacin
Also sold as Enablex. This medicine treats overactive bladder.
Data updated 2026-05-15
- 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.
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
- Peripheral Swelling
Peripheral Swelling
91 reports
- Herpes Zoster
Herpes Zoster
83 reports
- Pneumonia Viral
Pneumonia Viral
79 reports
- Anaemia
Anaemia
59 reports
- Arthralgia
Arthralgia
59 reports
- Oral Pain
Oral Pain
57 reports
- Arthritis
Arthritis
56 reports
- Blood Cholesterol Increased
Blood Cholesterol Increased
54 reports
- Liver Function Test Abnormal
Liver Function Test Abnormal
54 reports
- Synovitis
Synovitis
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) 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.
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.
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.
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.
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.
This is a plain-language summary of FDA-label interaction records and does not provide individual medication-combination directions.
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?
What pregnancy or breastfeeding source fields are listed for darifenacin?
Related Medications in Anticholinergic (Overactive Bladder)
Other drugs grouped near darifenacin - same-class peers and common alternatives.
alfuzosin
Uroxatral
Alfuzosin is a medicine that helps men with enlarged prostate glands.
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bethanechol
Urecholine
Bethanechol helps you to urinate if you have trouble emptying your bladder.
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dutasteride
Avodart
Dutasteride and tamsulosin hydrochloride capsules contain two medicines to treat enlarged prostate in men.
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dutasteride/tamsulosin
Jalyn
This medicine combines two drugs to treat enlarged prostate in men.
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fesoterodine
Toviaz
Fesoterodine is a medicine that helps control an overactive bladder.
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Compare beyond drug class
Nationwide peers by FAERS volume & death-report share
Two PlainMeds-derived comparison paths for darifenacin: nearest FDA FAERS report volume and nearest death-report share among drugs with at least 1,000 logged reports, excluding same-class neighbors listed above. Counts reflect reporting volume, not proven individual harm.
Similar FAERS report volume
Nearest drugs by total FAERS reports. This record: 596.
Similar death-report share
Nearest drugs by FAERS death-report share. This record: 9.40%.
- gabapentin Δ 0.01 pts · 351,750 reports · Anticonvulsant / Nerve Pain Agent 9.38%death share
- telmisartan Δ 0.02 pts · 33,611 reports · Angiotensin II Receptor Blocker (ARB) 9.42%death share
- dutasteride Δ 0.03 pts · 20,677 reports · 5-Alpha Reductase Inhibitor 9.43%death share
- baricitinib Δ 0.04 pts · 9,259 reports · JAK Inhibitor 9.35%death share
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
FDA bioequivalence and label-record context for narrow therapeutic index medicines
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 are separate source-record fields. This page is a public FDA/CMS registry and does not provide medical, treatment, substitution, or medication-change directions.
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. This registry does not provide medication decisions.
Last updated: April 19, 2024
PlainMeds is rendered directly from FDA openFDA/FAERS extracts, DailyMed labels, and CMS drug-pricing files, no number is typed in by an editor. FAERS counts, recalls, shortages, and price figures on this page are queried live from those federal extracts. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-05-15. Primary sources: openFDA / FAERS, DailyMed and CMS Part B ASP.
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