Description and Brand Names

Drug information provided by: Merative, Micromedex®

US Brand Name

1. Norpace
2. Norpace CR

Descriptions

Disopyramide is used to treat a life-threatening heart rhythm problem called ventricular arrhythmia, including sustained ventricular tachycardia.

This medicine is available only with your doctor's prescription.

This product is available in the following dosage forms:

• Capsule
• Capsule, Extended Release

Before Using

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

Appropriate studies have not been performed on the relationship of age to the effects of disopyramide in the pediatric population. Safety and efficacy have not been established.

Geriatric

Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of disopyramide in the elderly. However, elderly patients are more likely to have age-related liver, kidney, or heart problems, which may require caution and an adjustment in the dose for patients receiving disopyramide.

Breastfeeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Drug Interactions

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

• Bepridil
• Cisapride
• Dronedarone
• Fingolimod
• Itraconazole
• Ketoconazole
• Levoketoconazole
• Levomethadyl
• Mesoridazine
• Pimozide
• Piperaquine
• Posaconazole
• Sparfloxacin
• Terfenadine
• Thioridazine
• Vernakalant
• Ziprasidone

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

• Adagrasib
• Ajmaline
• Alfuzosin
• Amiodarone
• Amisulpride
• Amitriptyline
• Amoxapine
• Anagrelide
• Apomorphine
• Aprindine
• Aripiprazole
• Aripiprazole Lauroxil
• Arsenic Trioxide
• Asenapine
• Astemizole
• Atazanavir
• Azithromycin
• Bedaquiline
• Betaxolol
• Buprenorphine
• Buserelin
• Ceritinib
• Chloral Hydrate
• Chloroquine
• Chlorpromazine
• Chlorpropamide
• Ciprofloxacin
• Citalopram
• Clarithromycin
• Clofazimine
• Clomipramine
• Clothiapine
• Clozapine
• Cobicistat
• Crizotinib
• Cyclobenzaprine
• Dabrafenib
• Darunavir
• Dasabuvir
• Dasatinib
• Degarelix
• Delamanid
• Desipramine
• Deslorelin
• Deutetrabenazine
• Dexmedetomidine
• Dofetilide
• Dolasetron
• Domperidone
• Donepezil
• Doxepin
• Droperidol
• Efavirenz
• Eliglustat
• Encorafenib
• Enflurane
• Entrectinib
• Erythromycin
• Escitalopram
• Etrasimod
• Etravirine
• Fexinidazole
• Flecainide
• Fluconazole
• Fluoxetine
• Formoterol
• Foscarnet
• Fostemsavir
• Gatifloxacin
• Gemifloxacin
• Gepirone
• Glasdegib
• Glimepiride
• Glipizide
• Glyburide
• Gonadorelin
• Goserelin
• Granisetron
• Halofantrine
• Haloperidol
• Halothane
• Histrelin
• Hydroquinidine
• Hydroxychloroquine
• Hydroxyzine
• Ibutilide
• Iloperidone
• Imipramine
• Inotuzumab Ozogamicin
• Isoflurane
• Isradipine
• Ivabradine
• Ivosidenib
• Lacosamide
• Lapatinib
• Lefamulin
• Lenvatinib
• Leuprolide
• Levofloxacin
• Lidocaine
• Lidoflazine
• Lofexidine
• Lorcainide
• Lumefantrine
• Macimorelin
• Mefloquine
• Methadone
• Metronidazole
• Mexiletine
• Mifepristone
• Mirtazapine
• Mobocertinib
• Moxifloxacin
• Nafarelin
• Nalidixic Acid
• Nilotinib
• Nirmatrelvir
• Norfloxacin
• Nortriptyline
• Octreotide
• Ofloxacin
• Olanzapine
• Ombitasvir
• Ondansetron
• Osilodrostat
• Osimertinib
• Oxaliplatin
• Ozanimod
• Pacritinib
• Paliperidone
• Panobinostat
• Paritaprevir
• Paroxetine
• Pasireotide
• Pazopanib
• Pentamidine
• Phenobarbital
• Pimavanserin
• Pirmenol
• Pitolisant
• Ponesimod
• Prilocaine
• Primidone
• Probucol
• Procainamide
• Prochlorperazine
• Promethazine
• Propafenone
• Protriptyline
• Quetiapine
• Quinidine
• Quinine
• Quizartinib
• Relugolix
• Ribociclib
• Risperidone
• Ritonavir
• Selpercatinib
• Sertindole
• Sertraline
• Sevoflurane
• Simeprevir
• Siponimod
• Sodium Phosphate
• Sodium Phosphate, Dibasic
• Sodium Phosphate, Monobasic
• Solifenacin
• Sorafenib
• Sotalol
• Spiramycin
• Sulfamethoxazole
• Sulpiride
• Sultopride
• Sunitinib
• Tacrolimus
• Telavancin
• Telithromycin
• Tetrabenazine
• Tolazamide
• Tolbutamide
• Toremifene
• Trazodone
• Triclabendazole
• Trifluoperazine
• Trimethoprim
• Trimipramine
• Triptorelin
• Vandetanib
• Vardenafil
• Vemurafenib
• Venlafaxine
• Vilanterol
• Vinflunine
• Voclosporin
• Voriconazole
• Zolmitriptan
• Zotepine
• Zuclopenthixol

Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

• Atenolol
• Dalfopristin
• Digoxin
• Fosphenytoin
• Nevirapine
• Phenytoin
• Quinupristin
• Rifampin
• Rifapentine
• Warfarin

Other Interactions

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other Medical Problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

• Cardiogenic shock (shock caused by heart attack) or
• Enlarged prostate or
• Glaucoma, history of or
• Heart block, without a pacemaker or
• Heart failure or
• Heart rhythm problem (eg, asymptomatic ventricular premature contractions, long QT syndrome) or
• Hyperkalemia (high potassium in the blood) or
• Hypotension (low blood pressure) or
• Kidney disease, severe or
• Myasthenia gravis (severe muscle weakness) or
• Urinary retention (problems with passing urine)—Should not be used in patients with these conditions.

• Heart failure, history of
• Heart rhythm problem (eg, QT prolongation) or
• Malnutrition—Use with caution. May make these conditions worse.

• Liver disease—Use with caution. The effects may be increased because of slower removal of the medicine from the body.

• Sick sinus syndrome (type of abnormal heart rhythm) or
• Wolff-Parkinson-White syndrome (rare heart condition)—Use with caution. May cause very slow heartbeat in patients with these conditions.

Proper Use

Take this medicine only as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered. When your supply of this medicine is running low, contact your doctor or pharmacist ahead of time. Do not allow yourself to run out of this medicine.

Swallow the extended-release capsule whole. Do not crush, break, or chew it.

If you are taking verapamil, take it 48 hours after or 24 hours before taking this medicine.

Dosing

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

• For heart rhythm problems:
  • For oral dosage form (capsules):
    • Adults—400 to 800 milligrams (mg) per day given in divided doses. Dose is usually 600 mg per day given in divided doses (150 mg every 6 hours). Your doctor may adjust your dose as needed.
    • Adults weighing less than 50 kilograms (kg)—Dose is usually 400 mg per day given in divided doses (100 mg every 6 hours). Your doctor may adjust your dose as needed.
    • Children—Use and dose must be determined by your doctor.
  • For oral dosage forms (extended-release capsules):
    • Adults—400 to 800 milligrams (mg) per day given in divided doses. Dose is usually 600 milligrams (mg) per day given in divided doses (300 mg every 12 hours). Your doctor may adjust your dose as needed.
    • Adults weighing less than 50 kilograms (kg)—Dose is usually 400 mg per day given in divided doses (200 mg every 12 hours). Your doctor may adjust your dose as needed.
    • Children—Use and dose must be determined by your doctor.

Missed Dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Precautions

It is very important that your doctor check your progress at regular visits to make sure this medicine is working properly. Blood tests may be needed to check for unwanted effects.

Disopyramide may worsen the symptoms of heart failure in some patients. Check with your doctor right away if you are having chest pain or discomfort, dilated neck veins, extreme fatigue, irregular breathing or heartbeat, swelling of the face, fingers, feet, or lower legs, trouble breathing, or weight gain.

Contact your doctor right away if you have any changes to your heart rhythm. You might feel dizzy or faint, or you might have a fast, pounding, or uneven heartbeat. Make sure your doctor knows if you or anyone in your family has ever had a heart rhythm problem such as QT prolongation.

Do not suddenly stop taking this medicine without first checking with your doctor. Your doctor may want you to gradually reduce the amount you are taking before stopping it completely. Some conditions may become worse when the medicine is stopped suddenly, which can be dangerous.

This medicine may cause changes in your blood sugar levels. Also, this medicine may cover up signs of low blood sugar, such as a rapid pulse rate. Check with your doctor if you have these problems or if you notice a change in the results of your blood or urine sugar tests.

Dizziness, lightheadedness, or even fainting may occur when you get up suddenly from a lying or sitting position. Getting up slowly may help lessen this problem. Also, lying down for a while may relieve the dizziness or lightheadedness.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Side Effects

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

More common

1. Difficult urination
2. fainting
3. fast, slow, or irregular heartbeat
4. unusual tiredness

Less common

1. Blurred vision
2. chest pain
3. confusion
4. decrease in frequency of urination
5. decrease in urine volume
6. dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
7. itching, skin rash
8. lightheadedness
9. nervousness
10. painful urination
11. rapid weight gain
12. sweating
13. swelling of the face, fingers, feet, or lower legs
14. trouble breathing
15. unusual tiredness or weakness

Rare

1. Anxiety
2. chills
3. clay-colored stools
4. cold sweats
5. confusion
6. cool, pale skin
7. dark urine
8. diarrhea
9. discouragement
10. drowsiness
11. enlargement of breasts in men
12. fast heartbeat
13. feeling sad or empty
14. fever
15. headache
16. increased hunger
17. irritability
18. loss of appetite
19. loss of interest or pleasure
20. nausea
21. nosebleeds or bleeding gums
22. shakiness
23. sore throat
24. stomach pain
25. trouble concentrating
26. trouble sleeping
27. unpleasant breath odor
28. unsteady walk
29. vomiting of blood
30. yellow eyes or skin

Incidence not known

1. Chest tightness or discomfort
2. irregular breathing
3. pain or discomfort in the arms, jaw, back or neck

Get emergency help immediately if any of the following symptoms of overdose occur:

Symptoms of overdose

1. Bluish lips or skin
2. chest pain or discomfort
3. dizziness
4. fainting
5. fast, slow, or irregular heartbeat
6. lightheadedness
7. loss of consciousness
8. not breathing
9. pounding or rapid pulse

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

1. Constipation
2. dry eyes, mouth, nose, or throat

Less common

1. Bloating or stomach pain
2. decreased interest in sexual intercourse
3. inability to have or keep an erection
4. loss in sexual ability, desire, drive, or performance
5. muscle weakness
6. nervousness
7. weight loss

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Portions of this document last updated: March 01, 2024

Original article: https://www.mayoclinic.org/drugs-supplements/disopyramide-oral-route/before-using/drg-20063502