Ibutilide

Mechanism-of-action class: Unknown Cellular or Molecular Interaction.

• Ibutilide fumarate injection is indicated for the rapid conversion of atrial fibrillation or atrial flutter of recent onset to sinus rhythm. Patients with atrial arrhythmias of longer duration are less likely to respond to ibutilide fumarate.ICD-10: I48.91

• Ibutilide fumarate injection is contraindicated in patients who have previously demonstrated hypersensitivity to ibutilide fumarate or any of the other product components.contraindicated

The recommended dose based on controlled trials (see CLINICAL STUDIES ) is outlined in the Table below. Ibutilide infusion should be stopped as soon as the presenting arrhythmia is terminated or in the event of sustained or nonsustained ventricular tachycardia, or marked prolongation of QT or QTc. Recommended Dose of Ibutilide Fumarate Injection Patient Weight Initial Infusion (over 10 minutes) Second Infusion 60 kg (132 lb) or more One vial (1 mg ibutilide fumarate) If the arrhythmia does not terminate within 10 minutes after the end of the initial infusion, a second 10-minute infusion of equal strength may be administered 10 minutes after completion of the first infusion. Less than 60 kg (132 lb) 0.1 mL/kg (0.01 mg/kg ibutilide fumarate) In a trial comparing ibutilide and sotalol (see CLINICAL STUDIES ), 2 mg ibutilide fumarate administered as a single infusion to patients weighing more than 60 kg was also effective in terminating atrial fibrillation or atrial flutter. In the post-cardiac surgery study (see CLINICAL STUDIES ), one or two intravenous infusions of 0.5 mg (0.005 mg/kg per dose for patients weighing less than 60 kg) was effective in terminating atrial fibrillation or atrial flutter. Patients should be observed with continuous ECG monitoring for at least 4 hours following infusion or until QTc has returned to baseline. Longer monitoring is required if any arrhythmic activity is noted.

Proarrhythmia Like other antiarrhythmic agents, ibutilide fumarate injection can induce or worsen ventricular arrhythmias in some patients. This may have potentially fatal consequences. Torsades de pointes, a polymorphic ventricular tachycardia that develops in the setting of a prolonged QT interval, may occur because of the effect ibutilide fumarate has on cardiac repolarization, but ibutilide fumarate can also cause polymorphic VT in the absence of excessive prolongation of the QT interval. In general, with drugs that prolong the QT interval, the risk of torsades de pointes is thought to increase progressively as the QT interval is prolonged and may be worsened with bradycardia, a varying heart rate, and hypokalemia. In clinical trials conducted in patients with atrial fibrillation and atrial flutter, those with QTc intervals greater than 440 msec were not usually allowed to participate, and serum potassium had to be above 4 mEq/L. Although change in QTc was dose dependent for ibutilide, there was no clear relationship between risk of serious proarrhythmia and dose in clinical studies, possibly due to the small number of events. In clinical trials of intravenous ibutilide, patients with a history of congestive heart failure (CHF) or low left ventricular ejection fraction appeared to have a higher incidence of sustained polymorphic ventricular tachycardia (VT), than those without such underlying conditions; for sustained polymorphic VT the rate was 5.4% in patients with a history of CHF and 0.8% without it.

Ibutilide fumarate injection was generally well tolerated in clinical trials. Of the 586 patients with atrial fibrillation or atrial flutter who received ibutilide fumarate in phase II/III studies, 149 (25%) reported medical events related to the cardiovascular system, including sustained polymorphic ventricular tachycardia (1.7%) and nonsustained polymorphic ventricular tachycardia (2.7%). Other clinically important adverse events with an uncertain relationship to ibutilide fumarate include the following (0.2% represents one patient): sustained monomorphic ventricular tachycardia (0.2%), nonsustained monomorphic ventricular tachycardia (4.9%), AV block (1.5%), bundle branch block (1.9%), ventricular extrasystoles (5.1%), supraventricular extrasystoles (0.9%), hypotension/postural hypotension (2%), bradycardia/sinus bradycardia (1.2%), nodal arrhythmia (0.7%), congestive heart failure (0.5%), tachycardia/sinus tachycardia/supraventricular tachycardia (2.7%), idioventricular rhythm (0.2%), syncope (0.3%), and renal failure (0.3%). The incidence of these events, except for syncope, was greater in the group treated with ibutilide fumarate than in the placebo group. Another adverse reaction that may be associated with the administration of ibutilide fumarate was nausea, which occurred with a frequency greater than 1% more in ibutilide-treated patients than those treated with placebo. The medical events reported for more than 1% of the placebo- and ibutilide-treated patients are shown in the following Table.

Pregnancy Ibutilide administered orally was teratogenic (abnormalities included adactyly, interventricular septal defects, and scoliosis) and embryocidal in reproduction studies in rats. On a mg/m 2 basis, corrected for the 3% oral bioavailability, the “no adverse effect dose” (5 mg/kg/day given orally) was approximately the same as the maximum recommended human dose (MRHD); the teratogenic dose (20 mg/kg/day given orally) was about four times the MRHD on a mg/m 2 basis, or 16 times the MRHD on a mg/kg basis. Ibutilide fumarate should not be administered to a pregnant woman unless clinical benefit outweighs potential risk to the fetus.

Acute Experience in Animals Acute overdose in animals results in CNS toxicity; notably, CNS depression, rapid gasping breathing, and convulsions. The intravenous median lethal dose in the rat was more than 50 mg/kg which is, on a mg/m 2 basis, at least 250 times the maximum recommended human dose. Human Experience In the registration trials with ibutilide fumarate injection, four patients were unintentionally overdosed. The largest dose was 3.4 mg administered over 15 minutes. One patient (0.025 mg/kg) developed increased ventricular ectopy and monomorphic ventricular tachycardia, another patient (0.032 mg/kg) developed AV block—3rd degree and nonsustained polymorphic VT, and two patients (0.038 and 0.020 mg/kg) had no medical event reports. Based on known pharmacology, the clinical effects of an overdosage with ibutilide could exaggerate the expected prolongation of repolarization seen at usual clinical doses. Medical events (eg, proarrhythmia, AV block) that occur after the overdosage should be treated with measures appropriate for that condition.

• Dec 28, 1995NDANDA020491Pfizer
• Apr 1, 2024ANDAANDA204146Avet Lifesciences

1. 1Torsade De Pointes621%
2. 2Electrocardiogram Qt Prolonged517%
3. 3Ventricular Tachycardia517%
4. 4Atrial Fibrillation414%
5. 5Cardiac Arrest26.9%
6. 6Drug Interaction26.9%
7. 7Dyspnoea26.9%
8. 8Escherichia Infection26.9%
9. 9Hypotension26.9%
10. 10Neutropenia26.9%
11. 11Renal Failure26.9%
12. 12Abdominal Pain Upper13.4%
13. 13Accidental Exposure To Product13.4%
14. 14Asthenia13.4%
15. 15Blindness13.4%

The 10 most recently updated of 10 ClinicalTrials.gov registrations naming Ibutilide as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

• Pulsed Field Ablation Outcomes With Efficacy and Randomization in Atrial Fibrillation (POWER-AF)
  Recruiting · Interventional · 1,574 enrolled · China National Center for Cardiovascular Diseases
  NCT07601763updated 2026-05-28
• Novel Approaches for Minimizing Drug-Induced QT Interval Lengthening
  Completed · Phase 4 · Interventional · 73 enrolled · Indiana University
  NCT04675788updated 2026-03-19
• Reducing the Risk of Drug-Induced QT Interval Lengthening in Women
  Completed · Phase 4 · Interventional · 27 enrolled · Indiana University
  NCT03834883updated 2025-07-01
• ECGI in Patients With Persistent Atrial Fibrillation
  Completed · Observational · 50 enrolled · Pacific Rim Electrophysiology Research Institute
  NCT03836092updated 2022-04-12
• ECGi Ibutilide: Effect of Ibutilide on AF Source Location and Organization
  Terminated · Interventional · 1 enrolled · Vivek Reddy
  NCT03370536updated 2020-02-10
• Influence of Testosterone Administration on Drug-Induced QT Interval Prolongation and Torsades de Pointes
  Completed · Phase 4 · Interventional · 14 enrolled · Indiana University
  NCT02513940updated 2019-08-28
• Modified Ablation Guided by Ibutilide Use in Chronic Atrial Fibrillation
  Completed · Interventional · 200 enrolled · Vivek Reddy
  NCT01014741updated 2018-02-14
• Influence of Progesterone Administration on Drug-Induced QT Interval Lengthening
  Completed · Phase 2 · Interventional · 19 enrolled · Indiana University
  NCT01929083updated 2015-10-30
• Vernakalant Versus Ibutilide In Recent-Onset Atrial Fibrillation
  Completed · Phase 4 · Interventional · 101 enrolled · Medical University of Vienna
  NCT01447862updated 2015-05-13
• Ibutilide Administration During Pulmonary Vein Ablation
  Unknown · Interventional · 50 enrolled · Ball Memorial Hospital
  NCT00589992updated 2012-01-31

Frequently asked questions

How does Ibutilide work?

Mechanism-of-action class: Unknown Cellular or Molecular Interaction.

What is Ibutilide used for?

According to FDA labeling, Ibutilide carries indications including: Ibutilide fumarate injection is indicated for the rapid conversion of atrial fibrillation or atrial flutter of recent onset to sinus rhythm. Patients with atrial arrhythmias of longer duration are less likely to respond to ibutilide fumarate.. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.

What class of drug is Ibutilide?

Ibutilide is classified as Antiarrhythmics, class III, Antiarrhythmic, Unknown Cellular or Molecular Interaction, Delay Conduction System Repolarization, Lengthen Conduction System Depolarization Time.

What are the brand names for Ibutilide?

Ibutilide is marketed under brand names including Corvert.

What are the contraindications for Ibutilide?

Ibutilide labeling lists contraindications including: Ibutilide fumarate injection is contraindicated in patients who have previously demonstrated hypersensitivity to ibutilide fumarate or any of the other product components.. Always consult the full prescribing information and a clinician.