Bretylium

Treatment of serious or life-threatening arrhythmias (inhibits release of norepinephrine at postganglionic nerve endings)
Children: 2–5 mg/kg IV or IM, may repeat q 10–20 min (max: 30 mg/kg).
Adults: Initial dose or 5 mg/kg, then 10 mg/kg q 15–30 min (max: 35 mg/kg).
Note: Cardioversion/defibrillation must be attempted before and after each dose of bretylium.