ibutilide

Therapeutic Classification: antiarrhythmics (class III)

Indications ⬆ ⬇

REMS

Rapid conversion of recent-onset atrial flutter or fibrillation to normal sinus rhythm, including management of atrial flutter or fibrillation occurring within 1 wk of coronary artery bypass or cardiac valve surgery.

Action ⬆ ⬇

Activates slow inward current of sodium in cardiac tissue, resulting in delayed repolarization, prolonged action potential duration, and increased refractoriness.
Mildly slows sinus rate and AV conduction.

Therapeutic effects:

Conversion to normal sinus rhythm.

Pharmacokinetics ⬆ ⬇

Absorption: IV administration results in complete bioavailability.

Distribution: Unknown.

Metabolism/Excretion: Highly metabolized by the liver, one metabolite is active; metabolites excreted by kidneys.

Half-Life: 6 hr (2–12 hr).

Time/Action Profile ⬆ ⬇

(antiarrhythmic effect)

ROUTE	ONSET	PEAK	DURATION
IV	within 30–90 min	unknown	up to 24 hr

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity.

Use Cautiously in:

HF or left ventricular dysfunction (↑ risk of more serious arrhythmias during infusion);
OB: Pregnancy, lactation, or children 18 yr (safety not established).

Adv. Reactions/Side Effects ⬆ ⬇

CV: arrhythmias

GI: nausea

Neuro: headache

Interactions ⬆ ⬇

Drug-drug:

Amiodarone, disopyramide, procainamide, quinidine, and sotalol should not be given concurrently or within 4 hr because of additive effects on refractoriness.
Proarrhythmic effects may be ↑ by phenothiazines, tricyclic and tetracyclic antidepressants, some antihistamines, and histamine H2-receptor blocking agents; concurrent use should be avoided.

Route/Dosage ⬆ ⬇

Atrial Fibrillation/Flutter

Atrial Fibrillation/Flutter After Cardiac Surgery

IV (Adults ≥60 kg): 1 mg infusion; may be repeated 10 min after end of first infusion.
IV (Adults <60 kg): 0.01 mg/kg infusion; may be repeated 10 min after end of first infusion.
IV (Adults ≥60 kg): 0.5 mg infusion, may be repeated once.
IV (Adults <60 kg): 0.005 mg/kg infusion, may be repeated once.

Availability ⬆ ⬇

(Generic available)

Solution for injection: 0.1 mg/mL

Assessment ⬆ ⬇

Monitor ECG continuously throughout and for 4 hr after infusion or until QT interval normalizes. Discontinue if arrhythmia terminates or if sustained ventricular tachycardia, prolonged QT, or QT develops. Ibutilide may have proarrhythmic effects. These arrhythmias may be serious and potentially life threatening. Clinicians trained to treat ventricular arrhythmias, medications, and equipment (defibrillator/cardioverter) should be available during therapy and monitoring of patient.

Implementation ⬆ ⬇

Oral antiarrhythmic therapy may be instituted 4 hr after ibutilide infusion.

IV Administration:

Intermittent Infusion: Diluent: May be administered undiluted or diluted in 50 mL of 0.9% NaCl or D5W. Diluted solution is stable for 24 hr at room temperature or 48 hr if refrigerated.Concentration: Undiluted: 0.1 mg/mL; Diluted: 0.017 mg/mL.
Rate: Administer over 10 min.

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Pronunciation ⬇

Classifications ⬆ ⬇