Corvert

ibutilide fumarate

Corvert

Pharmacologic class: Ibutilide derivative

Therapeutic class: Antiarrhythmic (class III)

Pregnancy risk category C

FDA Box Warning

• Drug can cause potentially fatal arrhythmias-particularly sustained polymorphic ventricular tachycardia, usually in association with QT prolongation (torsades de pointes). In studies, these arrhythmias arose within several hours of administration. They can be reversed if treated promptly. Drug must be given in setting of continuous ECG monitoring and by personnel trained in identifying and treating acute ventricular arrhythmias. Patients with atrial fibrillation of more than 2 to 3 days' duration must be adequately anticoagulated, generally for at least 2 weeks.

• Patients with chronic atrial fibrillation tend to revert after conversion to sinus rhythm, and treatments to maintain sinus rhythm carry risks. Therefore, patients to be treated with drug should be selected carefully, with expected benefits of maintaining sinus rhythm outweighing drug's immediate risks and risks of maintenance therapy, and with drug offering benefits over alternative management.

Action

Prolongs myocardial action potential by slowing repolarization and atrioventricular (AV) conduction

Availability

Solution: 0.1 mg/ml in 10-ml vials

Indications and dosages

To convert atrial fibrillation or flutter to sinus rhythm

Adults weighing more than 60 kg (132 lb): 1 vial (1 mg) by I.V. infusion over 10 minutes. May repeat after 10 minutes if arrhythmia persists.

Adults weighing less than 60 kg (132 lb): 0.1 ml/kg (0.01 mg/kg) by I.V. infusion over 10 minutes. May repeat after 10 minutes if arrhythmia persists.

Contraindications

• Hypersensitivity to drug or its components

Precautions

Use cautiously in:

• ventricular and AV arrhythmias

• pregnant or breastfeeding patients.

Administration

See Monitor ECG continuously during and after infusion. Stop infusion immediately if ventricular tachycardia occurs.

• As appropriate, administer diluted or undiluted. To dilute, add 10-ml vial to 50 ml of normal saline solution or dextrose 5% in water, to yield a concentration of 0.017 mg/ml.

• Infuse over 10 minutes.

See Don't give with amiodarone, disopyramide, quinidine, procainamide, or sotalol, because of increased risk of dangerous arrhythmias.

Adverse reactions

CNS: headache, light-headedness, dizziness, numbness or tingling in arms

CV: hypotension, hypertension, bradycardia, bundle-branch block, ventricular extrasystoles, ventricular arrhythmias, ventricular tachycardia, AV heart block, heart failure

GI: nausea

GU: renal failure

Interactions

Drug-drug. Amiodarone, disopyramide, quinidine, procainamide, sotalol: increased risk of dangerous arrhythmias

Antihistamines, phenothiazines, tricyclic antidepressants: increased proarrhythmic effect (prolonged QT interval)

Patient monitoring

• Before giving, assess electrolyte levels and correct abnormalities (especially involving potassium and magnesium), because hypokalemia and hypomagnesemia can lead to arrhythmias.

See Watch for premature ventricular contractions, sinus tachycardia, sinus bradycardia, and heart block.

• Monitor ECG during and for at least 4 hours after infusion.

See Keep emergency equipment (defibrillator, emergency cart and drug box, oxygen, suction, and intubation equipment) at hand during and for at least 4 hours after infusion.

• Monitor prothrombin time, International Normalized Ratio, and activated partial thromboplastin time if patient is receiving anticoagulant therapy.

Patient teaching

See Instruct patient to immediately report chest pain, dizziness, numbness, palpitations, headache, or difficulty breathing.

• Tell patient he'll be monitored closely for at least 4 hours after drug administration.

ibutilide

(eye-byoo-ti-lide) ibutilide,

Corvert

(trade name)

Classification

Therapeutic: antiarrhythmics
Pregnancy Category: C

Indications

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 and 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)

ROUTEONSETPEAKDURATION
IVwithin 30–90 minunknownup to 24 hr

Contraindications/Precautions

Contraindicated in: Hypersensitivity.Use Cautiously in: HF or left ventricular dysfunction (↑ risk of more serious arrhythmias during infusion); Obstetric / Lactation / Pediatric: Pregnancy, lactation, or children <18 yr (safety not established).

Adverse Reactions/Side Effects

Central nervous system

  • headache

Cardiovascular

  • arrhythmias (most frequent)

Gastrointestinal

  • nausea

Interactions

Drug-Drug interaction

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 tetracyclicantidepressants, some antihistamines, and histamine H2-receptor blocking agents ; concurrent use should be avoided.

Route/Dosage

Atrial Fibrillation/FlutterIntravenous (Adults ≥60 kg) 1 mg infusion; may be repeated 10 min after end of first infusion.Intravenous (Adults <60 kg) 0.01 mg/kg infusion; may be repeated 10 min after end of first infusion.Atrial Fibrillation/Flutter After Cardiac SurgeryIntravenous (Adults ≥60 kg) 0.5 mg infusion, may be repeated once.Intravenous (Adults <60 kg) 0.005 mg/kg infusion, may be repeated once.

Availability (generic available)

Solution for injection: 0.1 mg/mL

Nursing implications

Nursing 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.

Potential Nursing Diagnoses

Decreased cardiac output (Indications)

Implementation

  • Oral antiarrhythmic therapy may be instituted 4 hr after ibutilide infusion.
  • Intravenous Administration
  • pH: 4.6.
  • 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.
  • Additive Incompatibility: Information unavailable; do not admix with other solutions or medications.

Patient/Family Teaching

  • Inform patient of the purpose of ibutilide.

Evaluation/Desired Outcomes

  • Conversion of recent-onset atrial flutter or fibrillation to normal sinus rhythm.