bretylium [IV]

Adult Dosing

Ventricular fibrillation or hemodynamically unstable ventricular tachycardia

1-2 mg/min continuous IV infusion
Maintenance dose: 5-10 mg/kg IV over a period >8 minutes, q6hrs

Other ventricular arrhythmias

Administer 5-10 mg/kg IV over a period >8 minutes
If arrhythmia persists administer subsequent doses at 1-2 hr intervals
Maintenance dose: 5 to 10 mg/kg IV q6hrs; Alt 1-2 mg/min continuous IV infusion

Notes

Patient should be placed in supine position during treatment or should be monitored for postural hypotension
Cardiopulmonary resuscitative procedures, including electrical cardioversion, should be used before initiating dose
Rapid infusion may cause nausea and vomiting, and may increase risk of orthostatic hypotension in patients older than 65 years
There is limited experience with administration of doses >40mg/kg/day, however clinical use of such doses has not been associated with adverse effects

Pediatric Dosing

Safety and efficacy in pediatric patients have not been established

[Outline]

Adult Dosing
Pediatric Dosing

Indications ⬆ ⬇

Prophylaxis and management of ventricular fibrillation
Ventricular arrhythmias refractory to first-line antiarrhythmic agents

Contraindications ⬆ ⬇

Hypersensitivity to any of the ingredients of the product

Black Box Warnings ⬆ ⬇

Dosing Adjustment ⬆ ⬇

Renal Dose Adjustment

Renal impairment: Reduce the dose and increase dosage interval

Hepatic Dose Adjustment

Hepatic impairment: Dose adjustments not defined

Warnings/Precautions ⬆ ⬇

Postural hypotension, dizziness, light-headedness, vertigo or faintnessin have been reported in patients during treatment. Hypotension may occur at doses lower than those required to suppress arrhythmias. Increased risk of orthostatic hypotension may occur in patient >65 yrs when the recommended rate of intravenous infusion is exceeded
Transient hypertension or increased frequency of premature ventricular contractions and other arrhythmias may occur in patients treated with bretylium
Use cautiously during use with digitalis glycosides. Bretylium should be used only if the cause of the arrhythmia does not appear to be digitalis toxicity and other antiarrhythmic drugs are ineffective. Avoid concomitant use of digitalis glycosides and bretylium
Avoid bretylium in patients with fixed cardiac output as severe hypotension may result from a fall in peripheral resistance without a compensatory increase in cardiac output
Hyperthermia may occur in patients treated with bretylium. If hyperthermia is diagnosed, discontinue bretylium and provide appropriate treatment

Pregnancy/Breast Feeding ⬆ ⬇

Pregnancy Category:C

Breastfeeding: Safety unknown. Little information is published about bretylium during breastfeeding, other agents may be preferred, especially while nursing a newborn or preterm infant. Breastfed infants should be carefully monitored if this drug is used during lactation, possibly including measurement of serum levels to rule out toxicity if there is a concern. This information is based upon LactMed database (available at http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT last accessed 09 January 2013).

Adverse Reactions ⬆ ⬇

CV: Hypotension, postural hypotension, bradycardia, arrhythmias, anginal attacks, shortness of breath
CNS: Dizziness, light-headedness, syncope
PSYCHIATRY: Confusion, paranoid psychosis, emotional lability, anxiety
GI: Nausea, vomiting, diarrhea, abdominal pain, hiccups
GU: Renal dysfunction
DERM: Erythematous macular rash, flushing, diaphoresis
EENT: Vertigo, nasal stuffiness, mild conjunctivitis
MISC: Hyperthermia, lethargy, generalized tenderness

Clinical Pharmacology ⬆ ⬇

Class III antiarrhythmic; inhibits norepinephrine release by depressing adrenergic nerve terminal excitability
No identifiable metabolites
Renally excreted in unchanged form
Half-life

Normal Patients: 7.8 +/- 0.6 hrs
Patient on hemodialysis: 13 hrs

Brands and Availability ⬆ ⬇