Ibutilide Fumarate

Generic Name: ibutilide fumarate

Over-the-Counter (OTC)

Brand Names:

Ibutilide Fumarate

DESCRIPTION Ibutilide Fumarate Injection is an antiarrhythmic drug with predominantly class III (cardiac action potential prolongation) properties according to the Vaughan Williams Classification. Each milliliter of Ibutilide Fumarate Injection contains 0.1 mg of ibutilide fumarate, USP (equivalent to 0.087 mg ibutilide free base), 0.189 mg sodium acetate trihydrate, USP, 8.90 mg sodium chloride, USP, hydrochloric acid NF and/or sodium hydroxide NF to adjust pH to approximately 4.6, and Water fo...

Overview

DESCRIPTION Ibutilide Fumarate Injection is an antiarrhythmic drug with predominantly class III (cardiac action potential prolongation) properties according to the Vaughan Williams Classification. Each milliliter of Ibutilide Fumarate Injection contains 0.1 mg of ibutilide fumarate, USP (equivalent to 0.087 mg ibutilide free base), 0.189 mg sodium acetate trihydrate, USP, 8.90 mg sodium chloride, USP, hydrochloric acid NF and/or sodium hydroxide NF to adjust pH to approximately 4.6, and Water fo...

Uses

INDICATIONS AND USAGE 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. The effectiveness of ibutilide has not been determined in patients with arrhythmias of more than 90 days in duration. LIFE-THREATENING ARRHYTHMIAS—APPROPRIATE TREATMENT ENVIRONMENT Ibutilide fumarate can cause potentially fatal arrhythmias, particularly sustained polymorphic ventricular tachycardia, usually in association with QT prolongation (torsades de pointes), but sometimes without documented QT prolongation.

Dosage

DOSAGE AND ADMINISTRATION 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.

Side Effects

ADVERSE REACTIONS 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%).

Interactions

Drug Interactions No specific pharmacokinetic or other formal drug interaction studies were conducted. Digoxin Supraventricular arrhythmias may mask the cardiotoxicity associated with excessive digoxin levels. Therefore, it is advisable to be particularly cautious in patients whose plasma digoxin levels are above or suspected to be above the usual therapeutic range. Co-administration of digoxin did not have effects on either the safety or efficacy of ibutilide in the clinical trials. Calcium channel blocking agents Co-administration of calcium channel blockers did not have any effect on either the safety or efficacy of ibutilide in the clinical trials.

Warnings

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

Pregnancy

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.

Storage

HOW SUPPLIED Ibutilide Fumarate Injection is supplied as an acetate-buffered isotonic solution at a concentration of 0.1 mg/mL that has been adjusted to approximately pH 4.6 in 10 mL clear glass, single-dose, flip-off vials.

Frequently Asked Questions

What is Ibutilide Fumarate used for?

INDICATIONS AND USAGE 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. The effectiveness of ibutilide has not been determined in patients with arrhythmias of more than 90 days in duration. LIFE-THREATENING ARRHYTHMIAS—APPROPRIATE TREATMENT ENVIRONMENT Ibutilide fumarate can cause potentially fatal arrhythmias, particularly sustained polymorphic ventricular tachycardia, usually in association with QT prolongation (torsades de pointes), but sometimes without documented QT prolongation.

What are the side effects of Ibutilide Fumarate?

ADVERSE REACTIONS 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%).

Can I take Ibutilide Fumarate during pregnancy?

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.

What are the important warnings for Ibutilide Fumarate?

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

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Medical Disclaimer

This drug information is for educational purposes only and should not replace professional medical advice. Drug information is sourced from the FDA National Drug Code Directory and Structured Product Labeling. Always consult with a healthcare provider before starting, stopping, or changing any medication.