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tikosyn

Pharmaranks rates Tikosyn 2.8/5 for recall safety — an independent score from its FDA recall history and its manufacturer's record. Tikosyn (Dofetilide) is an antiarrhythmic used to treat Atrial Fibrillation, Atrial Flutter.

Dofetilide · by Pfizer

56/100Limited · 1 source

Based on 1 source · Recall-safety score from FDA recall history — this product's own recalls and its manufacturer's record. Not an efficacy or quality rating. methodology →

Rated against independent regulatory sources·Last updated October 9, 2026·How we rate
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Key facts

Active ingredient
Dofetilide
Drug class
Antiarrhythmic
Form
Capsule
Strength
Dofetilide 0.125MG · Dofetilide 0.25MG · Dofetilide 0.5MG
Type
Prescription (Rx)
Brand or generic
Brand-name
Manufacturer
Pfizer
What the pharmacy pays
~$5.80 for 30 — not your price
FDA application
NDA020931

What is Tikosyn?

From the FDA label:TIKOSYN ® (dofetilide) is an antiarrhythmic drug with Class III (cardiac action potential duration prolonging) properties. Its empirical formula is C 19 H 27 N 3 O 5 S 2 and it has a molecular weight of 441.6. The structural formula is The chemical name for dofetilide is: N -[4-[2-[methyl[2-[4-[(methylsulfonyl)amino]phenoxy]ethyl]amino]ethyl]phenyl]-methanesulfonamide. Dofetilide is a white to off-white powder. It is very slightly soluble in water and propan-2-ol and is soluble in 0.1M aqueous sodium hydroxide, acetone, and aqueous 0.1M hydrochloric acid. TIKOSYN capsules contain the following inactive ingredients: microcrystalline cellulose, corn starch, colloidal silicon dioxide and magnesium stearate. TIKOSYN is supplied for oral administration in three dosage strengths: 125 mcg (0.125 mg) orange and white capsules, 250 mcg (0.25 mg) peach capsules, and 500 mcg (0.5 mg) peach and white capsules. Chemical Structure

How to use

Therapy with TIKOSYN must be initiated (and, if necessary, re-initiated) in a setting that provides continuous electrocardiographic (ECG) monitoring and in the presence of personnel trained in the management of serious ventricular arrhythmias. Patients should continue to be monitored in this way for a minimum of three days. Additionally, patients should not be discharged within 12 hours of electrical or pharmacological conversion to normal sinus rhythm. • The dose of TIKOSYN must be individualized according to calculated creatinine clearance and QTc. (QT interval should be used if the heart rate is <60 beats per minute. There are no data on use of TIKOSYN when the heart rate is <50 beats per minute.) The usual recommended dose of TIKOSYN is 500 mcg BID, as modified by the dosing algorithm described below. For consideration of a lower dose, see Special Considerations below. • Serum potassium should be maintained within the normal range before TIKOSYN treatment is initiated and should be maintained within the normal range while the patient remains on TIKOSYN therapy. (See WARNINGS, Hypokalemia and Potassium-Depleting Diuretics ). In clinical trials, potassium levels were generally maintained above 3.6–4.0 mEq/L. • Patients with atrial fibrillation should be anticoagulated according to usual medical practice prior to electrical or pharmacological cardioversion. Anticoagulant…

Side effects

The TIKOSYN clinical program involved approximately 8,600 patients in 130 clinical studies of normal volunteers and patients with supraventricular and ventricular arrhythmias. TIKOSYN was administered to 5,194 patients, including two large, placebo-controlled mortality trials (DIAMOND CHF and DIAMOND MI) in which 1,511 patients received TIKOSYN for up to three years. In the following section, adverse reaction data for cardiac arrhythmias and non-cardiac adverse reactions are presented separately for patients included in the supraventricular arrhythmia development program and for patients included in the DIAMOND CHF and MI mortality trials (see CLINICAL STUDIES, Safety in Patients with Structural Heart Disease, DIAMOND Studies , for a description of these trials). In studies of patients with supraventricular arrhythmias, a total of 1,346 and 677 patients were exposed to TIKOSYN and placebo for 551 and 207 patient years, respectively. A total of 8.7% of patients in the dofetilide groups were discontinued from clinical trials due to adverse events compared to 8.0% in the placebo groups. The most frequent reason for discontinuation (>1%) was ventricular tachycardia (2.0% on dofetilide vs. 1.3% on placebo). The most frequent adverse events were headache, chest pain, and dizziness. Serious Arrhythmias and Conduction Disturbances: Torsade de Pointes is the only arrhythmia that showed…

FDA Boxed Warning (the FDA’s most serious warning)

Boxed (black-box) warning — from the FDA label

To minimize the risk of induced arrhythmia, patients initiated or re-initiated on TIKOSYN should be placed for a minimum of 3 days in a facility that can provide calculations of creatinine clearance, continuous electrocardiographic monitoring, and cardiac resuscitation. For detailed instructions regarding dose selection, see DOSAGE AND ADMINISTRATION .

Warnings

Important safety information

Ventricular Arrhythmia: TIKOSYN (dofetilide) can cause serious ventricular arrhythmias, primarily Torsade de Pointes (TdP) type ventricular tachycardia, a polymorphic ventricular tachycardia associated with QT interval prolongation. QT interval prolongation is directly related to dofetilide plasma concentration. Factors such as reduced creatinine clearance or certain dofetilide drug interactions will increase dofetilide plasma concentration. The risk of TdP can be reduced by controlling the plasma concentration through adjustment of the initial dofetilide dose according to creatinine clearance and by monitoring the ECG for excessive increases in the QT interval. Treatment with dofetilide must therefore be started only in patients placed for a minimum of three days in a facility that can provide electrocardiographic monitoring and in the presence of personnel trained in the management of serious ventricular arrhythmias. Calculation of the creatinine clearance for all patients must precede administration of the first dose of dofetilide. For detailed instructions regarding dose selection, see DOSAGE AND ADMINISTRATION . The risk of dofetilide induced ventricular arrhythmia was assessed in three ways in clinical studies: 1) by description of the QT interval and its relation to the dose and plasma concentration of dofetilide; 2) by observing the frequency of TdP in TIKOSYN-treated patients according to dose; 3) by observing the overall mortality rate in patients with atrial fibrillation and in patients with structural heart disease. Relation of QT Interval to Dose: The QT interval increases linearly with increasing TIKOSYN dose (see Figures 1 and 2 in CLINICAL PHARMACOLOGY and Dose-Response and Concentration Response for Increase in QT Interval ). Frequency of Torsade de Pointes: In the supraventricular arrhythmia population (patients with AF and other supraventricular arrhythmias), the overall incidence of Torsade de Pointes was 0.8%. The frequency of TdP by dose is shown in Table 4. There were no cases of TdP on placebo. Table 4: Summary of Torsade de Pointes in Patients Randomized to Dofetilide by Dose; Patients with Supraventricular Arrhythmias TIKOSYN Dose <250 mcg BID 250 mcg BID >250–500 mcg BID >500 mcg BID All Doses Number of Patients 217 388 703 38 1346 Torsade de Pointes 0 1 (0.3%) 6 (0.9%) 4 (10.5%) 11 (0.8%) As shown in Table 5, the rate of TdP was reduced when patients were dosed according to their renal function (see CLINICAL PHARMACOLOGY, Pharmacokinetics in Special Populations, Renal Impairment and DOSAGE AND ADMINISTRATION ). Table 5: Incidence of Torsade de Pointes Before and After Introduction of Dosing According to Renal Function Population: Total Before After n/N % n/N % n/N % Supraventricular Arrhythmias 11/1346 (0.8%) 6/193 (3.1%) 5/1153 (0.4%) DIAMOND CHF 25/762 (3.3%) 7/148 (4.7%) 18/614 (2.9%) DIAMOND MI 7/749 (0.9%) 3/101 (3.0%) 4/648 (0.6%) DIAMOND AF 4/249 (1.6%) 0/43 (0%) 4/206 (1.9%) The majority of the episodes of TdP occurred within the first three days of TIKOSYN therapy (10/11 events in the studies of patients with supraventricular arrhythmias; 19/25 and 4/7 events in DIAMOND CHF and DIAMOND MI, respectively; 2/4 events in the DIAMOND AF subpopulation). Mortality: In a pooled survival analysis of patients in the supraventricular arrhythmia population (low prevalence of structural heart disease), deaths occurred in 0.9% (12/1346) of patients receiving TIKOSYN and 0.4% (3/677) in the placebo group. Adjusted for duration of therapy, primary diagnosis, age, gender, and prevalence of structural heart disease, the point estimate of the hazard ratio for the pooled studies (TIKOSYN/placebo) was 1.1 (95% CI: 0.3, 4.3). The DIAMOND CHF and MI trials examined mortality in patients with structural heart disease (ejection fraction ≤35%). In these large, double-blind studies, deaths occurred in 36% (541/1511) of TIKOSYN patients and 37% (560/1517) of placebo patients. In an analysis of 506 DIAMOND patients with atrial fibrillation/flutter at baseline, one year mortality on TIKOSYN was 31% vs. 32% on placebo (see CLINICAL STUDIES ). Because of the small number of events, an excess mortality due to TIKOSYN cannot be ruled out with confidence in the pooled survival analysis of placebo-controlled trials in patients with supraventricular arrhythmias. However, it is reassuring that in two large placebo-controlled mortality studies in patients with significant heart disease (DIAMOND CHF/MI), there were no more deaths in TIKOSYN-treated patients than in patients given placebo (see CLINICAL STUDIES ). Drug-Drug Interactions (see CONTRAINDICATIONS ) Because there is a linear relationship between dofetilide plasma concentration and QTc, concomitant drugs that interfere with the metabolism or renal elimination of dofetilide may increase the risk of arrhythmia (Torsade de Pointes). Dofetilide is metabolized to a small degree by the CYP3A4 isoenzyme of the cytochrome P450 system and an inhibitor of this system could increase systemic dofetilide exposure. More important, dofetilide is eliminated by cationic renal secretion, and three inhibitors of this process have been shown to increase systemic dofetilide exposure. The magnitude of the effect on renal elimination by cimetidine, trimethoprim, and ketoconazole (all contraindicated concomitant uses with dofetilide) suggests that all renal cation transport inhibitors should be contraindicated. Hypokalemia and Potassium-Depleting Diuretics Hypokalemia or hypomagnesemia may occur with administration of potassium-depleting diuretics, increasing the potential for Torsade de Pointes. Potassium levels should be within the normal range prior to administration of TIKOSYN and maintained in the normal range during administration of TIKOSYN (see DOSAGE AND ADMINISTRATION ). Use with Drugs that Prolong QT Interval and Antiarrhythmic Agents The use of TIKOSYN in conjunction with other drugs that prolong the QT interval has not been studied and is not recommended. Such drugs include phenothiazines, cisapride, bepridil, tricyclic antidepressants, certain oral macrolides, and certain fluoroquinolones. Class I or Class III antiarrhythmic agents should be withheld for at least three half-lives prior to dosing with TIKOSYN. In clinical trials, TIKOSYN was administered to patients previously treated with oral amiodarone only if serum amiodarone levels were below 0.3 mg/L or amiodarone had been withdrawn for at least three months.

Who should not take Tikosyn

TIKOSYN is contraindicated in patients with congenital or acquired long QT syndromes. TIKOSYN should not be used in patients with a baseline QT interval or QTc >440 msec (500 msec in patients with ventricular conduction abnormalities). TIKOSYN is also contraindicated in patients with severe renal impairment (calculated creatinine clearance <20 mL/min). The concomitant use of verapamil or the cation transport system inhibitors cimetidine, trimethoprim (alone or in combination with sulfamethoxazole), or ketoconazole with TIKOSYN is contraindicated (see WARNINGS and PRECAUTIONS, Drug-Drug Interactions ), as each of these drugs cause a substantial increase in dofetilide plasma concentrations. In addition, other known inhibitors of the renal cation transport system such as prochlorperazine, dolutegravir and megestrol should not be used in patients on TIKOSYN. The concomitant use of hydrochlorothiazide (alone or in combinations such as with triamterene) with TIKOSYN is contraindicated (see PRECAUTIONS, Drug-Drug Interactions ) because this has been shown to significantly increase dofetilide plasma concentrations and QT interval prolongation. TIKOSYN is also contraindicated in patients with a known hypersensitivity to the drug.

Overdose — what happens if you take too much

There is no known antidote to TIKOSYN; treatment of overdose should therefore be symptomatic and supportive. The most prominent manifestation of overdosage is likely to be excessive prolongation of the QT interval. In cases of overdose, cardiac monitoring should be initiated. Charcoal slurry may be given soon after overdosing but has been useful only when given within 15 minutes of TIKOSYN administration. Treatment of Torsade de Pointes or overdose may include administration of isoproterenol infusion, with or without cardiac pacing. Administration of intravenous magnesium sulfate may be effective in the management of Torsade de Pointes. Close medical monitoring and supervision should continue until the QT interval returns to normal levels. Isoproterenol infusion into anesthetized dogs with cardiac pacing rapidly attenuates the dofetilide-induced prolongation of atrial and ventricular effective refractory periods in a dose-dependent manner. Magnesium sulfate, administered prophylactically either intravenously or orally in a dog model, was effective in the prevention of dofetilide-induced Torsade de Pointes ventricular tachycardia. Similarly, in man, intravenous magnesium sulfate may terminate Torsade de Pointes, irrespective of cause. TIKOSYN overdose was rare in clinical studies; there were two reported cases of TIKOSYN overdose in the oral clinical program. One patient…

U.S. Poison Control: call or text 1-800-222-1222 (free, 24/7). In an emergency call 911. From the FDA label; not medical advice.

Drug class

How this class works, per Antiarrhythmic Medications - StatPearls - NCBI Bookshelf.

May treat (source: NIH RxClass)

See how Tikosyn ranks — best-rated antiarrhythmic for:

Dosage forms

Capsule

The forms currently marketed in the U.S., per the FDA National Drug Code Directory.

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Frequently asked questions

What does Tikosyn treat?
Tikosyn (Dofetilide) may be used to treat atrial fibrillation, atrial flutter, based on NIH RxClass drug-classification data (conditions a drug may treat — not a verbatim copy of the FDA-approved label). This is general reference, not medical advice.
How does Tikosyn work?
Tikosyn is a 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.
How is Tikosyn rated?
pharmaranks gives Tikosyn a composite score of 2.8 out of 5, currently based on 1 weighted source (FDA regulatory recall-safety data weighted highest). See our methodology at /how-we-rate.
How much does Tikosyn cost?
Nobody can tell you what you will pay — your price is set by your insurer's formulary, your deductible and the pharmacy's markup, and none of those are published. What IS published is what the pharmacy paid to acquire it: about $5.80 for 30, per the CMS NADAC survey. Treat that as the floor, not the quote — ask the pharmacist for the cash price as well as your copay, because for cheap generics the cash price often wins. Pharmacies pay less for a same-class option, Betapace — about $3.00 on the same basis.
Is there a coupon or discount for Tikosyn?
pharmaranks is an independent ratings site, not a pharmacy — we don't issue coupons or sell Tikosyn. To pay less, ask your prescriber or pharmacist whether a generic equivalent exists, check the manufacturer's copay/savings card and patient-assistance program, and compare a pharmacy discount card against your insurance copay. Prices vary by pharmacy, insurance, and location, so always confirm at the counter. This is general reference, not medical or financial advice.
Who makes Tikosyn?
Tikosyn is marketed by Pfizer. You can see Pfizer's full profile, rating, and other products on pharmaranks.
Is Tikosyn a brand-name or generic drug?
Tikosyn is a brand-name product with the active ingredient Dofetilide.
Is Tikosyn available over the counter?
No. Tikosyn is a prescription (Rx) medication in the US — you need a prescription from a licensed clinician (in person or via telehealth); it isn't sold over the counter. For some conditions there are OTC alternatives — ask your pharmacist.
What forms does Tikosyn come in?
Tikosyn is currently marketed as capsule, per the FDA's National Drug Code Directory.
What class of drug is Tikosyn?
Tikosyn is classified as antiarrhythmic, per the FDA's Established Pharmacologic Class.
Is Tikosyn FDA-registered?
Tikosyn is on record with the U.S. FDA under application number NDA020931. You can verify this on its official FDA label.
Has Tikosyn been recalled by the FDA?
Yes. Tikosyn has 1 recorded FDA recall event in the openFDA enforcement database. A recall removes specific lots from the market — usually for manufacturing, contamination, potency, or labeling issues — and does not mean the drug is unsafe to take; your specific lot was almost certainly never affected. This recall history is factored into its safety score above. Always check the FDA recall database or your pharmacist for current alerts.
Is Tikosyn safe?
There's no single safe-or-not verdict. pharmaranks gives Tikosyn a recall-safety score of 56/100, based on its FDA recall history (1 recorded recall event) — not an efficacy or side-effect rating. Review its FDA-label side effects and warnings before use, and always consult a licensed professional.
What are the side effects of Tikosyn?
Tikosyn's side effects are taken directly from its FDA label. From the label: The TIKOSYN clinical program involved approximately 8,600 patients in 130 clinical studies of normal volunteers and patients with supraventricular and ventricular arrhythmias. TIKOSYN was administered to 5,194 patients, including two large,… Both common and serious reactions are documented in full on this page. This is general reference from the FDA, not medical advice — always consult a professional.

Clinical content sourced from the FDA label via openFDA (U.S. FDA). View the FDA label on DailyMed → Provided for general reference only — not medical advice. Always consult a licensed professional and the current prescribing information.

What people report to the FDA about DOFETILIDE

The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 2,898 reports naming DOFETILIDE — the active ingredient in Tikosyn, and the FDA flagged 65% 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:

  • atrial fibrillation254 reports
  • electrocardiogram qt prolonged186 reports
  • dyspnoea163 reports
  • dizziness132 reports
  • fatigue126 reports
  • headache100 reports
  • diarrhoea95 reports
  • torsade de pointes93 reports

Read these as a signal, not a rate. A report does not mean DOFETILIDE 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.

Source: openFDA drug/event (FAERS), retrieved September 25, 2026.

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