IV antihypertensive dosing

Bolus doses, starting infusion rates and titration steps for the IV drugs used in hypertensive emergencies, converted to mg/h and pump rate in mL/h from the weight and an editable concentration. Each drug lists its onset and offset, contraindications, cautions, best indications and use in pregnancy, with the cyanide and thiocyanate warning for nitroprusside. Urapidil, widely used in Europe, is included as the ESC alternative. Ticking sacubitril/valsartan or a PDE5 inhibitor flags the ACE inhibitor and the nitric oxide donors as contraindicated.

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Drug

Revise the patient's medications

Ask before giving any drug in the ER

Patient

Weight is needed for this drug

Weight

Infusion concentration

Default: 200 mg in 200 mL (or undiluted 5 mg/mL via pump)

Concentration

mg/mL

Combined α1- and non-selective β-blocker

Labetalol

Onset 5–10 min · offset 3–6 h

Malignant hypertension, encephalopathy, stroke, ACS without heart failure, pre-eclampsia, aortic dissection when esmolol is unavailable

Pregnancy: first line

Bolus

0.3–1.0 mg/kg (max 20 mg) slow IV over 2 min every 10 min; or the fixed regimen 20 mg, then 40 mg, then 80 mg every 10 min. Maximum cumulative dose 300 mg.

Infusion and titration

Infusion 0.4–1.0 mg/kg/h, up to 3 mg/kg/h (commonly 0.5–2 mg/min, i.e. 30–120 mg/h). Stop at a cumulative 300 mg.

Dose (mg/kg/h)	mg/h	Pump (mL/h)
0.4start	—	—
0.7	—	—
1	—	—
1.5	—	—
2	—	—
3max	—	—

Enter the weight to convert the weight-based doses.

Contraindications

Second- or third-degree AV block, sinus bradycardia
Acute decompensated (systolic) heart failure or cardiogenic shock
Asthma or reactive airways disease
Cocaine or amphetamine intoxication, phaeochromocytoma without prior α-blockade

Cautions

Long offset makes overshoot hard to reverse
Neonatal bradycardia and hypoglycaemia after use in pregnancy (monitor the baby)

Check doses against your local formulary and pump library. Pump rates assume the concentration above.

IV antihypertensives at a glance

Doses from the ACC/AHA 2017 hypertension guideline (Table 19–20) and the ESC 2024 / ESC Council on Hypertension emergency tables

Drug	Dose	Onset	Offset	Main contraindications
Labetalol	0.4–3 mg/kg/h (± bolus)	5–10 min	3–6 h	Second- or third-degree AV block, sinus bradycardia; Acute decompensated (systolic) heart failure or cardiogenic shock; Asthma or reactive airways disease; Cocaine or amphetamine intoxication, phaeochromocytoma without prior α-blockade
Nitroglycerin (glyceryl trinitrate)	5–200 µg/min	1–5 min	3–5 min	PDE5 inhibitor in the last 24 h (sildenafil, vardenafil), 12 h (avanafil) or 48 h (tadalafil, including 5 mg daily for BPH); Right ventricular infarction, hypovolaemia; Severe aortic stenosis or HOCM with obstruction
Sodium nitroprusside	0.3–10 µg/kg/min	Immediate (seconds)	1–2 min (rebound when stopped abruptly)	PDE5 inhibitor in the last 24–48 h (nitric oxide donor: same interaction as nitrates); Pregnancy (fetal cyanide), except as a last resort; Severe hepatic failure (cyanide) or renal failure (thiocyanate); Leber optic atrophy, B12 deficiency, congenital cyanide-metabolism disorders
Nicardipine	5–15 mg/h	5–15 min	30–40 min (up to 4 h after long infusions)	Advanced aortic stenosis
Clevidipine	1–32 mg/h	2–4 min	5–15 min	Soy or egg allergy; Defective lipid metabolism (pathological hyperlipidaemia, lipoid nephrosis, acute pancreatitis with hyperlipidaemia); Advanced aortic stenosis
Esmolol	50–300 µg/kg/min (± bolus)	1–2 min	10–30 min	Second- or third-degree AV block, sinus bradycardia; Decompensated heart failure or cardiogenic shock; Cocaine or amphetamine intoxication, phaeochromocytoma without prior α-blockade
Urapidil	5–40 mg/h (± bolus)	3–5 min	4–6 h	Aortic isthmus stenosis (coarctation); Arteriovenous shunt other than a dialysis fistula; Breastfeeding
Phentolamine	Bolus	1–2 min	10–30 min	Acute coronary syndrome or known severe coronary disease (reflex tachycardia); Tachyarrhythmia
Hydralazine	Bolus	10–20 min (unpredictable)	2–4 h (up to 12 h)	Aortic dissection (reflex tachycardia, raised dP/dt); Acute coronary syndrome; Systemic lupus erythematosus
Enalaprilat	Bolus	15–30 min	6–12 h	Sacubitril/valsartan (Entresto) within the last 36 h (angioedema); Pregnancy (second and third trimester fetotoxicity); History of angioedema; Bilateral renal artery stenosis; Acute kidney injury, hypovolaemia (high-renin states fall precipitously)

References