Comprehensive medication guide to Quinidine including estimated pricing, availability information, side effects, and how to find it in stock at your local pharmacy.
Estimated Insurance Pricing
Generic quinidine is typically covered at Tier 1–2 on most commercial insurance plans and Medicare Part D, with copays of $0–$30 per month. Mail-order 90-day supplies often offer the lowest effective cost. Prior authorization is not commonly required, though some plans may require step therapy or quantity limits.
Estimated Cash Pricing
Quinidine sulfate tablets retail for $325–$1,290 for 30 tablets without insurance; with GoodRx coupons, prices drop to as low as $29.59. Quinidine gluconate ER 324 mg tablets retail for $534–$589 per 30 tablets; with GoodRx, as low as $147.16. Prices vary by formulation, strength, and pharmacy.
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Quinidine is one of the oldest antiarrhythmic medications in medicine, derived from the bark of the South American cinchona tree — the same plant that produces quinine. It has been used to treat abnormal heart rhythms since the early 20th century. Despite being largely replaced by newer antiarrhythmics for many indications, quinidine remains a critical medication for specific patient populations.
Quinidine is classified as a Class IA antiarrhythmic under the Vaughan Williams classification. It is FDA-approved for atrial fibrillation and flutter (to restore and maintain normal sinus rhythm), life-threatening ventricular arrhythmias, and severe P. falciparum malaria. Low-dose quinidine is also an ingredient in Nuedexta (combined with dextromethorphan) for pseudobulbar affect.
All brand-name versions of quinidine — including Quinaglute, Quinidex, Cardioquin, and Quinora — have been discontinued. Only generic quinidine is currently manufactured, available as quinidine sulfate (200 mg and 300 mg immediate-release tablets) and quinidine gluconate extended-release tablets (324 mg). The IV formulation was permanently discontinued in the US in 2019.
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Quinidine works through multiple mechanisms simultaneously. Its primary antiarrhythmic action is blockade of the fast inward sodium channel (Nav1.5) in cardiac cells — the channel responsible for the rapid electrical signal that triggers each heartbeat. By blocking this channel, quinidine slows electrical conduction through the heart, makes it harder for arrhythmia-generating cells to fire spontaneously, and widens the QRS complex on EKG.
Quinidine also blocks multiple potassium channels (IKr, IKs, Ito, IK1, IKATP), which prolongs the action potential duration and the QT interval. Its blockade of the transient outward potassium current (Ito) is uniquely important for Brugada syndrome, where Ito is disproportionately active and triggers ventricular fibrillation. No other widely available oral antiarrhythmic has this same Ito-blocking property.
Additionally, quinidine has anticholinergic (vagolytic) effects — it blocks the vagus nerve's slowing influence on the heart — and alpha-1 adrenergic blocking effects that can lower blood pressure. For malaria, quinidine acts as a blood schizonticide, killing Plasmodium falciparum parasites in red blood cells by disrupting their ability to process hemoglobin.
200 mg — tablet (quinidine sulfate, immediate-release)
Taken every 6 hours; most common formulation for arrhythmia management
300 mg — tablet (quinidine sulfate, immediate-release)
Taken every 6 hours; higher-dose immediate-release option
324 mg — extended-release tablet (quinidine gluconate)
Taken every 8–12 hours; formerly sold as Quinaglute; more convenient dosing schedule
Quinidine availability is inconsistent across the United States. As of 2026, there is no active FDA-declared nationwide shortage, but patients frequently report difficulty finding it at their usual pharmacy — particularly for the quinidine gluconate extended-release formulation. Chain pharmacies often do not keep quinidine in stock due to its relatively low prescribing volume. Independent pharmacies, hospital-affiliated pharmacies, and specialty pharmacies are more likely to carry it.
The availability challenge is structural rather than crisis-driven: all brand-name versions are discontinued, only a small number of generic manufacturers produce it, and chain pharmacy inventory systems deprioritize low-demand generics. Patients who cannot find quinidine at their pharmacy should call ahead, ask about special ordering, try independent pharmacies, or use mail-order pharmacy for 90-day supplies.
If you're having trouble locating quinidine, medfinder calls pharmacies near you on your behalf to find which ones can fill your prescription, then texts you the results — saving you hours of frustration.
Quinidine is not a controlled substance and requires no special DEA registration. Any licensed prescriber may write a quinidine prescription. However, because initiating quinidine requires a baseline EKG, electrolyte testing, and careful drug interaction review — and because it carries a boxed warning about mortality risk — it is typically initiated by cardiac specialists and managed by:
Cardiac electrophysiologists (EPs) — especially for Brugada syndrome, idiopathic VF, and short QT syndrome
Cardiologists — for atrial fibrillation and ventricular arrhythmias
Internists and primary care physicians — for ongoing management of stable patients initiated by specialists
Infectious disease specialists — for malaria treatment
Nurse practitioners (NPs) and physician assistants (PAs) in cardiology or internal medicine settings
Telehealth is generally not appropriate for initiating quinidine due to the need for in-person EKG and lab monitoring. Ongoing management of stable patients may sometimes be handled via telehealth with appropriate remote monitoring in place. Patients seeking a new quinidine prescription should ask their primary care physician for a referral to a cardiologist or electrophysiologist.
No. Quinidine is not a controlled substance and has no DEA schedule. Any licensed prescriber in the United States can write a prescription for quinidine without special DEA registration or other controlled substance requirements. Prescriptions can be written for larger quantities or with refills without the restrictions that apply to scheduled medications.
Although quinidine is not a controlled substance, it does carry an FDA boxed warning about increased mortality risk in patients with non-life-threatening arrhythmias. As a result, quinidine is typically initiated and monitored by cardiologists or electrophysiologists, who perform baseline EKG and electrolyte testing before prescribing and monitor cardiac function during treatment.
The most common quinidine side effects are gastrointestinal and affect many patients, especially when starting:
Nausea (most common)
Vomiting
Diarrhea
Stomach cramps
Dizziness and lightheadedness
Headache
Seek immediate medical care for any of the following:
Torsades de pointes — life-threatening arrhythmia (fainting, rapid heartbeat, loss of consciousness; call 911)
Cinchonism — toxicity syndrome: tinnitus (ringing ears), visual disturbances, confusion
Thrombocytopenia — low platelet count (easy bruising, bleeding)
Hepatotoxicity — liver damage (jaundice, dark urine)
Agranulocytosis — severe drop in white blood cells
Drug-induced lupus — joint pain, rash, fever
Severe allergic reaction — hives, difficulty breathing, facial swelling
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Amiodarone (Cordarone, Pacerone)
Class III antiarrhythmic widely used for both AFib and ventricular arrhythmias; highly effective but requires thyroid, liver, and lung monitoring with long-term use
Flecainide (Tambocor)
Class IC antiarrhythmic commonly used for AFib in patients without structural heart disease; widely available as generic; contraindicated after heart attack or with significant LV dysfunction
Propafenone (Rythmol)
Class IC antiarrhythmic similar to flecainide with added beta-blocking properties; used for AFib and SVT; avoid in structural heart disease
Mexiletine
Class IB antiarrhythmic primarily for ventricular arrhythmias; does not prolong QT interval; also used off-label for pain conditions
Sotalol (Betapace)
Class III antiarrhythmic with beta-blocking properties; used for AFib and ventricular arrhythmias; prolongs QT interval; hospital initiation typically required
Disopyramide (Norpace)
Class IA antiarrhythmic in same class as quinidine; useful for AFib in hypertrophic obstructive cardiomyopathy; significant anticholinergic side effects
Prefer Quinidine? We can find it.
Digoxin
majorQuinidine can double serum digoxin levels by inhibiting P-glycoprotein and renal tubular secretion. Digoxin dose should be reduced 25–50% when quinidine is started, with close monitoring of digoxin levels.
Warfarin
majorQuinidine enhances anticoagulant effect of warfarin. Monitor INR closely when quinidine is started, stopped, or dose-adjusted. Warfarin dose may need reduction.
Amiodarone
majorAmiodarone inhibits quinidine metabolism, raising quinidine blood levels and prolonging QT interval. Use together only with careful monitoring.
Rifampin
majorPowerful CYP3A4 inducer; dramatically lowers quinidine levels, potentially to sub-therapeutic concentrations. May require large dose increases (up to threefold).
Moxifloxacin / Levofloxacin (fluoroquinolone antibiotics)
majorAdditive QT prolongation; high risk of torsades de pointes. Avoid this combination.
Pimozide
majorSevere QT prolongation risk. Contraindicated combination — do not use together.
Tricyclic antidepressants (amitriptyline, nortriptyline, desipramine)
majorQuinidine strongly inhibits CYP2D6, raising TCA blood levels to potentially toxic concentrations. Avoid combination or reduce TCA dose with close monitoring.
Ketoconazole / Itraconazole (antifungals)
moderateCYP3A4 inhibitors that raise quinidine levels; increased risk of quinidine toxicity and QT prolongation.
Cimetidine (Tagamet)
moderateOTC antacid that inhibits quinidine metabolism; raises quinidine levels. Patients should inform their pharmacist they are on quinidine before buying OTC heartburn medications.
Verapamil
moderateAdditive hypotension due to alpha-blocking effects; use together may cause significant blood pressure drop.
Codeine / Hydrocodone
moderateQuinidine blocks CYP2D6 conversion of codeine and hydrocodone to their active metabolites. These opioids may be largely ineffective in patients on quinidine.
Grapefruit juice
minorInhibits CYP3A4 metabolism of quinidine; can raise quinidine levels. Avoid large quantities of grapefruit juice while on quinidine.
Quinidine is a medication with a century of clinical history — and for the right patient, it remains irreplaceable. While its role has narrowed as newer antiarrhythmics have emerged, patients with Brugada syndrome, idiopathic ventricular fibrillation, short QT syndrome, or refractory atrial fibrillation who respond to quinidine may depend on it for life-saving arrhythmia control.
The challenges around quinidine — inconsistent availability, complex drug interactions, a demanding side effect profile — are real but manageable with the right support. If you're on quinidine, keep a supply buffer, know which pharmacies in your area carry it, and maintain regular follow-up with your cardiologist for EKG and lab monitoring.
If you ever find yourself struggling to fill your quinidine prescription, medfinder is here to help. We call pharmacies near you on your behalf and text you which ones can fill your prescription — saving you the time and stress of tracking it down yourself.
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Our medication guides are researched and written to help patients make informed decisions. All content is reviewed for accuracy and updated regularly. Learn more about our standards
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