Table 1.

Initial dosing of antihypertensive agents^a

Agent	Comment
Enalaprilat	Intravenous intermittent: 0.625–1.25 mg (lower dose if hyponatremia, possible volume depletion, concomitant diuretic therapy, or renal failure) over 5 min, then double at 4- to 6-h intervals until desired response, a single maximal dose of 1.25–5 mg (doses ≥1.25 mg have not been of additional benefit, but doses ≤5 mg have been given), toxicity, or a cumulative dose of 20 mg within a 24-h period; contraindicated in 2nd and 3rd trimester of pregnancy
Esmolol	Intravenous infusion: 250–500 μg/kg/min for 1 min, followed by a 50–100 μg/kg/min infusion for 4 min, then titrate using same sequence (ie, with bolus before each rate increase) until desired response, a maximal dose of 300 μg/kg/min, or toxicity
Fenoldopam	Intravenous intermittent: 0.1 μg/kg/min initially, then titrate in 0.1 μg/kg/min increments every 15 min until desired response, a maximal dose of 1.6 μg/kg/min, or toxicity
Hydralazine	Intravenous intermittent: 3–20 mg (the lower end of the dosing range is preferred in the immediate perioperative period and in patients with renal failure) slow IV push every 20–60 min
Labetalol	Intravenous intermittent: 20 mg over 2 min, then double at 10 min intervals until desired response, a single maximal dose of 80 mg, toxicity, or a cumulative dose of 300 mg/d Intravenous infusion: 2 mg/min initially, then titrate in 2 mg increments every 10 min until response, toxicity, or a cumulative dose of 300 mg/24-h
Nicardipine	Intravenous infusion: 5 mg/h initially, then titrate dose by 2.5 mg/h increments every 5–15 min until desired response, a maximal dose of 15 mg/h, or toxicity
Nitroglycerin	Intravenous infusion: 5 μg/min initially, then titrate in 5 μg/min increments (may use 10 to 20 μg/min increments when doses >20 μg/min) every 3–5 min until desired response or toxicity; no absolute dosing limit, but the risk of hypotension increases with doses >200 μg/min; therefore, alternative therapy should be considered
Nitroprusside	Intravenous infusion: 0.25–0.5 μg/kg/min initially, then titrate dose every 1–2 min until desired response, a maximal dose of 10 μg/kg/min (limit to duration <10 min), or toxicity

^aNotes: Use oral dosing when gastrointestinal absorption is documented and when an early response (eg, <2 h) is not needed; the IV dose titration times are the shortest times recommended for BP control but not necessarily the best for a given patient; slower titrations are often warranted to preclude excessively rapid decreases in pressure, with subsequent perfusion complications.