Comes as 5 mg/mL ampoules

Blocks α, β1, and β2 adrenergic receptor sites.
Decreases heart rate and peripheral vascular resistance.

Ratio of alpha to beta blockade depends upon the route of administration (1:3 oral versus 1:7 IV)

Onset of action: 2‐5 minutes

Will not cause bronchoconstriction

Duration: 2‐4 hours

IV Bolus: 20 mg over at least 2 minutes as initial dose, may repeat with doses of 40-‐ 80 mg q10min; Do not exceed total dose of 300 mg

Infusion [ dilution 1 mg/mL] : starting 2 mg/min (2 mL/min) – 8 mg/min titrated to response. Do not exceed total dose of 300

As cumulative dose nears 300mg IV, duration of action extends to nearly 18 hours.

Ref: B Xu, F Charlton, A Makris, A Hennessy – Journal of hypertension, 2014