Nursebob’s MICU/CCU Survival Guide
Critical Care Medication
Cardiogenic Drugs
Antiarrhythmic
Ibutilide
1/13/2006

1. Indication
            A. Considered to be an effective alternative to electrical cardioversion for Rapid conversion of atrial fibrillation and atrial flutter.
            B. Ibutilide is moderately effective in causing prompt conversion to sinus rhythm with greater efficacy in patients who have atrial flutter.

2. Action.
            A. Ibutilide prolongs action potential duration by activating a slow inward current, largely carried by sodium ions.
            B. Blocks the rapidly activating component of the delayed rectifier potassium current.
            C. No significant effect on heart rate, PR interval, or QRS interval
            D. Potential prolongation by Ibutilide leads to an increase in atrial and ventricular refractoriness in vivo.
            E. No clinically significant effect of Ibutilide to lower blood pressure or worsen congestive heart failure.
            F. Route of elimination: hepatic.

3. Administration.
            A. Ibutilide is available in 10 mL vials containing 0.1 mg/mL (1 mg total).
            B. For intravenous administration, the recommended dose of Ibutilide is 1mg over a 10 minute period in patients weighing > 60 kg
            C. Patients weighing < 60 kg, the recommended dose is 0.01 mg/kg initially, with a second dose of the same strength 10 minutes later if necessary.
            D. Ten minutes after the end of the initial infusion, a second 10 minute infusion of equal strength can be given if the arrhythmia has not terminated.

4. Cautions.
            A. Prolong ventricular repolarization
            B. Carries a risk of excessive QT prolongation
            C. Acquired long-QT syndrome
            D. Associated polymorphic ventricular tachycardia (torsade de pointes)
            E. Careful patient selection and clinical monitoring during drug administration.

5. Contraindications.
            A. QTc interval exceeding 440ms
            B. Bradycardia
            C. Electrolyte disturbances
            D. Other QT-prolonging drugs

6. Adverse Effects.
            A. Ventricular tachycardia
            B. Premature ventricular complexes
            C. Hypotension
            D. Bundle branch block
            E. Atrioventricular

Reference:- K.T. Murray: Ibutilide
Circulation. 1998; 97:493-97

- Scrip 1996; Jan 19; 2095:20