Disopyramide: uses, dosing, side effects & brands
Disopyramide is an antiarrhythmic sold in the U.S. under one brand, for atrial fibrillation, atrial flutter and ventricular premature complexes. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.
Key facts
- Drug class
- Antiarrhythmic
- Treats
- Atrial Fibrillation, Atrial Flutter and Ventricular Premature Complexes
- Available as
- Capsule
- Sold as
- Norpace
- Prescription?
- Prescription only
- Generic available?
- Not in our catalog
- What the pharmacy pays
- about $25 for a 30-count supply — not your price
- Boxed warning
- Boxed warning
How disopyramide is dosed
From the FDA label for Norpace (application NDA017447). Other disopyramide products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
The dosage of disopyramide phosphate must be individualized for each patient on the basis of response and tolerance. The usual adult dosage of disopyramide phosphate is 400 to 800 mg per day given in divided doses. The recommended dosage for most adults is 600 mg/day given in divided doses (150 mg every 6 hours for immediate-release disopyramide phosphate). For patients whose body weight is less than 110 pounds (50 kg), the recommended dosage is 400 mg/day given in divided doses (100 mg every 6 hours for immediate-release disopyramide phosphate). In the event of increased anticholinergic side effects, plasma levels of disopyramide should be monitored and the dose of the drug adjusted accordingly. A reduction of the dose by one third, from the recommended 600 mg/day to 400 mg/day, would be reasonable, without changing the dosing interval. For patients with cardiomyopathy or possible cardiac decompensation, a loading dose, as discussed below, should not be given, and initial dosage should be limited to 100 mg of immediate-release disopyramide phosphate every 6 to 8 hours. Subsequent dosage adjustments should be made gradually, with close monitoring for the possible development of hypotension and/or congestive heart failure (see Warnings ). For patients with moderate renal insufficiency (creatinine clearance greater than 40 ml/min) or hepatic insufficiency, the recommended dosage…
Disopyramide side effects
The adverse reactions which were reported in disopyramide phosphate clinical trials encompass observations in 1,500 patients, including 90 patients studied for at least 4 years. The most serious adverse reactions are hypotension and congestive heart failure. The most common adverse reactions, which are dose dependent, are associated with the anticholinergic properties of the drug. These may be transitory, but may be persistent or can be severe. Urinary retention is the most serious anticholinergic effect. The following reactions were reported in 10% to 40% of patients: Anticholinergic: dry mouth (32%), urinary hesitancy (14%), constipation (11%) The following reactions were reported in 3% to 9% of patients: Anticholinergic: blurred vision, dry nose/eyes/throat Genitourinary: urinary retention, urinary frequency and urgency Gastrointestinal: nausea, pain/bloating/gas General: dizziness, general fatigue/muscle weakness, headache, malaise, aches/pains The following reactions were reported in 1% to 3% of patients: Genitourinary: impotence Cardiovascular: hypotension with or without congestive heart failure, increased congestive heart failure (see Warnings ), cardiac conduction disturbances (see Warnings ), edema/weight gain, shortness of breath, syncope, chest pain Gastrointestinal: anorexia, diarrhea, vomiting Dermatologic: generalized rash/dermatoses, itching Central nervous…
Who shouldn’t take disopyramide
Disopyramide phosphate is contraindicated in the presence of cardiogenic shock, preexisting second-or third-degree AV block (if no pacemaker is present), congenital Q-T prolongation, or known hypersensitivity to the drug.
Disopyramide drug interactions
If phenytoin or other hepatic enzyme inducers are taken concurrently with disopyramide phosphate, lower plasma levels of disopyramide may occur. Monitoring of disopyramide plasma levels is recommended in such concurrent use to avoid ineffective therapy. Other antiarrhythmic drugs (e.g., quinidine, procainamide, lidocaine, propranolol) have occasionally been used concurrently with disopyramide phosphate. Excessive widening of the QRS complex and/or prolongation of the Q-T interval may occur in these situations (see Warnings ). In healthy subjects, no significant drug-drug interaction was observed when disopyramide phosphate was coadministered with either propranolol or diazepam. Concomitant administration of disopyramide phosphate and quinidine resulted in slight increases in plasma disopyramide levels and slight decreases in plasma quinidine levels. Disopyramide phosphate does not increase serum digoxin levels. Until data on possible interactions between verapamil and disopyramide phosphate are obtained, disopyramide should not be administered within 48 hours before or 24 hours after verapamil administration. Although potent inhibitors of cytochrome P450 3A4 (e.g., ketoconazole) have not been studied clinically, in vitro studies have shown that erythromycin and oleandomycin inhibit the metabolism of disopyramide. Cases of life-threatening interactions have been reported for disopyramide when given with clarithromycin and erythromycin indicating that coadministration of disopyramide with inhibitors of cytochrome 3A4 could result in potentially fatal interaction.
Every disopyramide product we track (1)
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
Only one: Norpace.
What disopyramide pills look like
Imprint codes, colour and shape from the FDA’s labelling data. Match the imprint on your pill — or search any imprint.
| Imprint | Strength | Colour | Shape | Maker |
|---|---|---|---|---|
| SEARLE;2752;NORPACE;100;MG | 100 mg | white, orange | capsule | — |
| SEARLE;2762;NORPACE;150;MG | 150 mg | brown, orange | capsule | — |
| SEARLE;2752;NORPACE;100;MG | 100 mg | white, orange | capsule | — |
| SEARLE;2762;NORPACE;150;MG | 150 mg | brown, orange | capsule | — |
| SEARLE;2732;NORPACE;CR;100;MG | 100 mg | white, green | capsule | — |
| SEARLE;2742;NORPACE;CR;150;MG | 150 mg | brown, green | capsule | — |
| m;095 | 100 mg | orange | capsule | — |
| m;096 | 150 mg | brown | capsule | — |
| 93;3127;93;3127 | 100 mg | blue, red | capsule | — |
| 93;3129;93;3129 | 150 mg | brown, red | capsule | — |
| m;095 | 100 mg | orange | capsule | — |
| m;096 | 150 mg | brown | capsule | — |
How long disopyramide keeps
No disopyramide label we read sets a separate limit for after opening, but they do specify how it must be stored — and the stability behind any date assumes those conditions.
Does disopyramide expire? The in-use limits and storage rules from its labelsDisopyramide and breastfeeding
From LactMed, the US National Library of Medicine’s Drugs and Lactation Database — quoted, not rewritten.
Full LactMed record for disopyramide: levels in milk, effects in breastfed infants, and the drugs it would consider insteadDisopyramide is sometimes found in the plasma of nursing infants at levels of 7.5% to 12.5% of the mother's levels. The N-monodesalkyldisopyramide (NMD) metabolite is more anticholinergic than disopyramide itself and appears in breastmilk in levels higher than disopyramide. However, of the cases reported, there are no reports of infant effects. Disopyramide may be used cautiously while breastfeeding when other alternatives are unacceptable. Observe the infant for anticholinergic symptoms. Infant serum concentrations can be monitored if there is any concern about drug-induced adverse effects. Theoretically, disopyramide might decrease the milk supply.
National Institute of Child Health and Human Development, record revised September 15, 2024. LactMed states its information is not a substitute for professional judgement.
What people report to the FDA about disopyramide
The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 336 reports naming disopyramide, and the FDA flagged 63% of those reports as serious. The effects reported most often — leaving out reports about overdose, misuse or the condition being treated, which dominate the raw list for common medicines:
- malaise19 reports
- atrial fibrillation16 reports
- electrocardiogram qt prolonged14 reports
- dizziness13 reports
- feeling abnormal13 reports
- asthenia12 reports
- dyspnoea12 reports
- loss of consciousness11 reports
Read these as a signal, not a rate. A report does not mean disopyramide caused the effect — anyone can file one, and many describe people taking several medicines for several conditions. Crucially there is no denominator: FAERS does not record how many people took the drug, so these counts cannot be turned into “X% of patients” — a bigger number often just means a more widely used or more talked-about drug. Duplicates exist, and publicity drives reporting. For what is actually established, read the FDA label section above.
Source: openFDA drug/event (FAERS), retrieved July 25, 2026.
Related calculators
Frequently asked questions
What is disopyramide?
Disopyramide phosphate is an antiarrhythmic drug available for oral administration in immediate-release capsules containing 100 mg or 150 mg of disopyramide base, present as the phosphate. The base content of the phosphate salt is 77.6%.
What kind of drug is disopyramide?
The FDA classifies disopyramide as an antiarrhythmic. Antiarrhythmics steady an irregular heartbeat by controlling the flow of sodium, potassium, or calcium ions through heart-cell channels (or blunting adrenaline's effect), which slows or normalizes the heart's electrical signals so it beats in a more regular rhythm. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.
Can you take disopyramide with other medicines?
It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run disopyramide against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What forms does disopyramide come in?
Across the brands we track, disopyramide is currently marketed as capsule, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.
Is there a generic disopyramide?
We do not currently list a generic-labelled disopyramide product. That does not always mean none exists — it means none appears under a generic name in the FDA data we track. Ask your pharmacist.
Cite this page
- APA
- pharmaranks. (2026, July 24). Disopyramide: uses, dosing, side effects & brands. https://pharmaranks.com/drugs/disopyramide
- MLA
- “Disopyramide: uses, dosing, side effects & brands.” pharmaranks, 24 July 2026, https://pharmaranks.com/drugs/disopyramide.
We summarise public FDA and NIH sources — for a clinical claim, cite the primary source we link to as well.
Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.
Read the full FDA label for disopyramide on DailyMed (NIH) ↗ — including its boxed warning in full.