Cardioquin

Quinidine is a prescription medication used to treat abnormal heart rhythms. It is also used to treat malaria. Quinidine belongs to a group of drugs called antiarrhythmics. These work by making your heart more resistant to abnormal activity. 

This medication comes in tablet form and is taken up to 3 times a day. This medication comes in extended release tablet form and is taken up to 3 times a day. Do not crush or chew quinidine tablets. Tablets can be broken in half. This medication is also available in an injectable form to be given directly into a vein (IV) by a healthcare professional. 

Common side effects of quinidine include diarrhea, lightheadedness, and headache. Quinidine can also cause dizziness. Do not drive or operate heavy machinery until you know how quinidine affects you. 

Cardioquin is part of the drug class:

• Antiarrhythmics, class Ia

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.

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.

Pregnancy

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.

• Amifampridine
• Amisulpride
• Aurothioglucose
• Bepridil
• Cisapride
• Colchicine
• Dronedarone
• Fingolimod
• Fluconazole
• Grepafloxacin
• Itraconazole
• Ketoconazole
• Levomethadyl
• Mesoridazine
• Mifepristone
• Nelfinavir
• Pimozide
• Piperaquine
• Posaconazole
• Ritonavir
• Saquinavir
• Sparfloxacin
• Terfenadine
• Thioridazine
• Tipranavir
• Vernakalant
• Voriconazole
• 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.

• Acetazolamide
• Afatinib
• Ajmaline
• Alefacept
• Alfuzosin
• Amiodarone
• Amitriptyline
• Amoxapine
• Amphetamine
• Amprenavir
• Anagrelide
• Apomorphine
• Aprindine
• Arbutamine
• Aripiprazole
• Aripiprazole Lauroxil
• Arsenic Trioxide
• Artemether
• Asenapine
• Astemizole
• Atazanavir
• Atracurium
• Azithromycin
• Bedaquiline
• Benzphetamine
• Betrixaban
• Blinatumomab
• Boceprevir
• Brexpiprazole
• Buserelin
• Ceritinib
• Chloral Hydrate
• Chloroquine
• Ciprofloxacin
• Citalopram
• Clarithromycin
• Clomipramine
• Clozapine
• Cobicistat
• Conivaptan
• Crizotinib
• Cyclobenzaprine
• Dabigatran Etexilate
• Dabrafenib
• Dasabuvir
• Dasatinib
• Decamethonium
• Degarelix
• Delamanid
• Delavirdine
• Desipramine
• Deslorelin
• Deutetrabenazine
• Dextroamphetamine
• Digitoxin
• Digoxin
• Disopyramide
• Dofetilide
• Dolasetron
• Domperidone
• Donepezil
• Doxepin
• Doxorubicin
• Doxorubicin Hydrochloride Liposome
• Droperidol
• Efavirenz
• Eliglustat
• Eluxadoline
• Enflurane
• Enzalutamide
• Erythromycin
• Escitalopram
• Etravirine
• Flecainide
• Fosamprenavir
• Foscarnet
• Gatifloxacin
• Gemifloxacin
• Golimumab
• Gonadorelin
• Goserelin
• Granisetron
• Guselkumab
• Halofantrine
• Haloperidol
• Halothane
• Histrelin
• Hydroquinidine
• Hydroxychloroquine
• Hydroxyzine
• Ibutilide
• Idelalisib
• Imipramine
• Infliximab
• Isavuconazonium Sulfate
• Isoflurane
• Isradipine
• Ivabradine
• Lanreotide
• Lapatinib
• Leuprolide
• Levofloxacin
• Lidocaine
• Lidoflazine
• Lisdexamfetamine
• Lopinavir
• Lorcainide
• Lumacaftor
• Lumefantrine
• Mefloquine
• Methadone
• Methamphetamine
• Metronidazole
• Mexiletine
• Morphine
• Morphine Sulfate Liposome
• Moxifloxacin
• Nafarelin
• Nalidixic Acid
• Nebivolol
• Netupitant
• Nilotinib
• Norfloxacin
• Nortriptyline
• Octreotide
• Ofloxacin
• Ombitasvir
• Ondansetron
• Paliperidone
• Pancuronium
• Panobinostat
• Paritaprevir
• Pasireotide
• Pazopanib
• Pentamidine
• Pimavanserin
• Pirmenol
• Pitolisant
• Pixantrone
• Prilocaine
• Probucol
• Procainamide
• Prochlorperazine
• Propafenone
• Protriptyline
• Quetiapine
• Quinidine
• Quinine
• Ranolazine
• Ribociclib
• Salmeterol
• Secukinumab
• Sevoflurane
• Simeprevir
• Sodium Phosphate
• Sodium Phosphate, Dibasic
• Sodium Phosphate, Monobasic
• Solifenacin
• Sorafenib
• Sotalol
• Spiramycin
• Succinylcholine
• Sulfamethoxazole
• Sulpiride
• Sunitinib
• Tacrolimus
• Telaprevir
• Telavancin
• Telithromycin
• Tetrabenazine
• Tizanidine
• Topotecan
• Toremifene
• Trazodone
• Trifluoperazine
• Trimethoprim
• Trimipramine
• Triptorelin
• Tubocurarine
• Ulipristal
• Valbenazine
• Vandetanib
• Vardenafil
• Vasopressin
• Vecuronium
• Vemurafenib
• Venetoclax
• Vilazodone
• Vincristine
• Vincristine Sulfate Liposome
• Vinflunine
• Vortioxetine
• Zolmitriptan
• 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.

• Abarelix
• Amiloride
• Atenolol
• Cimetidine
• Dalfopristin
• Dextromethorphan
• Dicumarol
• Fosphenytoin
• Galantamine
• Magaldrate
• Magnesium Carbonate
• Magnesium Hydroxide
• Magnesium Oxide
• Magnesium Trisilicate
• Nifedipine
• Nisoldipine
• Paroxetine
• Phenobarbital
• Phenytoin
• Propranolol
• Quinupristin
• Rifapentine
• Tolterodine
• Tramadol
• Verapamil

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.

• Grapefruit Juice

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:

• Electrolyte disorders—Quinidine may worsen heart rhythm problems

• Heart disease or
• Myasthenia gravis—Quinidine may make these conditions worse

• Kidney disease or
• Liver disease—Effects may be increased because of slower removal of quinidine from the body

Tablet (sulfate):100 to 600 mg/dose orally every 4 to 6 hours; begin at 200 mg/dose and titrate to desired effect (maximum daily dose: 3 to 4 g).
Extended Release: 324 to 648 mg (gluconate) orally every 8 to 12 hours or 300 to 600 mg (sulfate) orally every 8 to 12 hours.
IV: 800 mg of quinidine gluconate diluted to 50 mL and given at a rate not to exceed 1 mL/min.

If creatinine clearance is less than 10 mL/minute, administer 75% of normal dose.

Dosages exceeding 648 mg (gluconate) every 8 hours or 600 mg (sulfate) every 6 hours are not recommended except for patients with relatively large actual body weight.

Quinidine has been assigned to pregnancy category C by the FDA. Animal studies have not been reported. There are no controlled data in human pregnancy. Quinidine should be given during pregnancy only when benefit outweighs risk.

Quinidine crosses the placenta, with umbilical cord blood to maternal serum concentration ratios ranging from 0.2 to 0.8. Quinidine, when compared to many other cardiovascular drugs, is considered relatively safe for the fetus. Quinidine has been used successfully and safely to treat resistant fetal tachyarrhythmias and to treat acute malaria in pregnant women. Neonatal thrombocytopenia has been reported after maternal ingestion of quinidine. Data from the Michigan Medicaid Birth Defects Study has failed to reveal an association between quinidine and congenital abnormalities (written communication, Franz Rosa, MD, Food and Drug Administration, 1994). This was a retrospective study of 229,101 completed pregnancies between 1985 and 1992, of which 17 were exposed to quinidine at some time during the first trimester, and 68 were exposed to the drug at any time during pregnancy. Of these pregnancies, a single birth defect was observed. This observation did not achieve statistical significance. There were no observations of cardiovascular defects, cleft palate, spina bifida, polydactyly, limb reduction, or hypospadias. These data do not support an association between quinidine and birth defects.

Summary of Use during Lactation

Limited information indicates that maternal doses of quinidine up to 1.8 grams daily produce low levels in milk and would not be expected to cause any adverse effects in breastfed infants, especially if the infant is older than 2 months. Exclusively breastfed infants should be carefully monitored if this drug is used during lactation, possibly including measurement of serum levels to rule out toxicity if there is a concern.

Drug Levels

Maternal Levels. In one case report, a quinidine milk level of 6.4 mg/L was reported 3 hours after a dose while taking 600 mg every 8 hours orally of a sustained-release quinidine sulfate preparation (Quninidex). In the same patient, a random milk level of 8.2 mg/L was also measured.[1] Data from this case indicate that a breastfed infant would receive about 3 to 4% of the maternal weight-adjusted dosage of quinidine.

Infant Levels. Relevant published information was not found as of the revision date.

Effects in Breastfed Infants

Relevant published information was not found as of the revision date.

Effects on Lactation and Breastmilk

Relevant published information was not found as of the revision date.

References

1. Hill LM, Malkasian GD Jr. The use of quinidine sulfate throughout pregnancy. Obstet Gynecol. 1979;54:366-8. PMID: 471380

LactMed Record Number

235

Last Revision Date

20150310

Disclaimer

Information presented in this database is not meant as a substitute for professional judgment. You should consult your healthcare provider for breastfeeding advice related to your particular situation. The U.S. government does not warrant or assume any liability or responsibility for the accuracy or completeness of the information on this Site.