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Quinidine (Oral, Injection, Intramuscular)

Generic name: quinidine [ KWIN-i-deen ]
Brand names: Cardioquin, Quinaglute, Quinalan, Quinidex Extentabs
Drug class: Group I antiarrhythmics

Medically reviewed by Drugs.com. Last updated on Dec 4, 2023.

Oral route(Tablet)

Many trials of antiarrhythmic therapy for non-life threatening arrhythmias, has resulted in increased mortality; the risk of active therapy is probably greatest in patients with structural heart disease. In the case of quinidine used to prevent or defer recurrence of atrial flutter/fibrillation, meta-analysis data has shown that the mortality associated with the use of quinidine was more than three times greater than placebo. Another meta-analysis showed that in patients with various non-life-threatening ventricular arrhythmias, the mortality associated with the use of quinidine was consistently greater than that associated with the use of any of a variety of alternative antiarrhythmics .

Oral route(Tablet)

Active antiarrhythmic therapy has resulted in increased mortality; the risk of active therapy is probably greatest in patients with structural heart disease. In a meta-analysis, the mortality associated with the use of quinidine was more than 3 times as great as the mortality associated with the use of placebo. Another meta-analysis showed that in patients with various non-life-threatening ventricular arrhythmias, the mortality associated with the use of quinidine was consistently greater than that associated with the use of alternative antiarrhythmics .

Oral route(Tablet, Extended Release)

Active antiarrhythmic therapy has resulted in increased mortality; the risk is probably greatest in patients with structural heart disease .

Uses for quinidine

Quinidine is used to treat abnormal heart rhythms. It is also used to treat malaria.

Do not confuse this medicine with quinine, which, although related, has different medical uses.

Quinidine is available only with your doctor's prescription.

Before using quinidine

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

Quinidine has not been widely studied in children; however, it is used in children to treat abnormal heart rhythms and to treat malaria. Children may be able to take higher doses than adults and may have fewer side effects (such as vomiting, loss of appetite, and diarrhea) than adults.

Geriatric

Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults. Although there is no specific information comparing use of quinidine in the elderly with use in other age groups, this medicine is not expected to cause different side effects or problems in older people than it does in younger adults. However, quinidine may remain in the bodies of older adults longer than it does in younger adults, which may increase the risk of side effects and which may require lower doses.

Breast Feeding

Studies in women suggest that this medication poses minimal risk to the infant when used during breastfeeding.

Interactions with Medicines

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.

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.

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.

Interactions with Food/Tobacco/Alcohol

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. 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 may cause an increased risk of certain side effects but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use this medicine, or give you special instructions about the use of 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:

Proper use of quinidine

Take this medicine exactly as directed. Do not take more of this medicine and do not take it more often than your doctor ordered. Do not miss any doses.

Taking quinidine with food may help lessen stomach upset.

For patients taking the extended-release tablet form of 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.

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.

doxycycline, amiodarone, clindamycin, hydroxychloroquine, lidocaine, verapamil, Plaquenil, dofetilide, Vibramycin

Precautions while using quinidine

It is very important that your doctor check your progress at regular visits to make sure that the quinidine is working properly and does not cause unwanted effects.

Do not stop taking this medicine without first checking with your doctor, to avoid possible worsening of your condition.

Before having any kind of surgery (including dental surgery) or emergency treatment, tell the medical doctor or dentist in charge that you are taking this medicine.

Dizziness or lightheadedness may occur with this medicine, especially when you get up from a lying or sitting position. Getting up slowly may help.

Fainting may occur with this medicine. Do not drive or do anything else that could be dangerous if fainting occurs.

. Check with your doctor immediately if you faint or experience other side effects with this medicine.

Your doctor may want you to carry a medical identification card or bracelet stating that you are using this medicine.

Side Effects of quinidine

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:

Less common

Rare

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

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.

Commonly used brand name(s)

In the U.S.

Available Dosage Forms:

Therapeutic Class: Antiarrhythmic, Group IA

Chemical Class: Cinchona Alkaloid

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.