Basic Neuroscience · Neuropharmacology
Antihypertensives in the ICU
IV agents for hypertension and tachycardia in the neuro-ICU. Verify every dose against your institutional protocol before use.
Hypertension — IV agents
| Drug | Dose | MOA | Onset | Duration | Metabolism | Notes & clinical pearls |
|---|---|---|---|---|---|---|
| ✓ Preferred / safe in neuro patients — minimal effect on ICP | ||||||
| Clevidipine | 1–2 mg/hr, double q90 s; usual ≤16 mg/hr | Dihydropyridine CCB (arterial) | 2–4 min | 5–15 min | Blood/tissue esterases | Preferred neuro agent — fast on/off, safe in hepatic/renal failure. Lipid emulsion: avoid egg/soy allergy, severe aortic stenosis; monitor triglycerides. |
| Nicardipine | 5 mg/hr, ↑ 2.5 q5–15 min; max 15 mg/hr | Dihydropyridine CCB (arterial) | 5–10 min | ~30 min offset | Hepatic | Preferred neuro agent — smooth control in stroke & hypertensive encephalopathy. Reflex tachycardia, flushing; phlebitis (rotate site / central). |
| Labetalol | 20 mg IV bolus, then 40–80 mg q10 min or 0.5–2 mg/min; max 300 mg/episode | α1 + nonselective β | 2–5 min | 2–6 h | Hepatic | Aortic dissection, sympathetic surge; ok in pregnancy. Avoid: bradycardia, block, decompensated HF, asthma, cocaine. |
| Phentolamine | 5 mg IV bolus, repeat q10 min PRN | α1/α2 blocker | 1–2 min | 15–30 min | Hepatic | Catecholamine crisis (cocaine, pheo, MAOI, clonidine withdrawal) — treats HTN + tachycardia. Also reverses pressor extravasation. |
| Enalaprilat | 1.25 mg IV q6 h; max 5 mg q6 h | ACE inhibitor | 15–30 min | ~6 h | Renal | No ICP effect but slow, poorly titratable — not first-line. Hyperkalemia, angioedema; avoid bilateral RAS / pregnancy. |
| ✗ Not preferred in neuro patients — raise ICP | ||||||
| Hydralazine | 10–20 mg IV bolus q4–6 h | Direct arteriolar | 10–30 min | 2–4 h (variable) | Hepatic | ↑ICP, ↓CPP, unpredictable — avoid in ICH/TBI/edema. Reflex tachycardia; lupus (chronic); ok in eclampsia. |
| Sodium nitroprusside | 0.3–0.5 mcg/kg/min; max 10 | NO donor (art. + venous) | <1 min | 1–2 min | Hb → cyanide → thiocyanate (renal) | ↑ICP, coronary steal, cyanide/thiocyanate & methemoglobinemia (worse in organ failure). Light-protect. |
| Nitroglycerin | 5 → 200 mcg/min | NO donor (venous > art.) | 2–5 min | 3–10 min | RBC / vascular | ↑ICP. Tolerance, headache; contraindicated with PDE5 inhibitors. For cardiac ischemia / pulmonary edema. |
| Fenoldopam | 0.01–0.3 mcg/kg/min | D1 agonist | 5–15 min | ~30 min | Conjugation (renal) | ↑IOP (glaucoma), possible ↑ICP. Improves renal perfusion; hypokalemia; sulfite; limited US supply. |
Tachycardia / rate control — IV agents
| Drug | Dose | MOA | Onset | Duration | Notes |
|---|---|---|---|---|---|
| Esmolol | 500 mcg/kg load over 1 min, then 25–50 → 200 mcg/kg/min | β1 blocker | ~5 min | 10–20 min | Ultra-short — ideal titratable. Avoid: bradycardia, block, decompensated HF, asthma/COPD. |
| Metoprolol | 5 mg IV q5 min ×3 (max 15 mg) | β1 blocker | ~5 min | 3–4 h | AFib/flutter, ACS. Avoid: decompensated HF, bradycardia, block, bronchospasm. |
| Diltiazem | 0.25 mg/kg IV load (0.35 if needed), then 10 mg/hr (5–15) | Non-DHP CCB | 2–7 min | 1–3 h (bolus) | AFib/flutter RVR, SVT. Avoid: decompensated HF, pre-excited AF / accessory pathway, wide-complex VT. |
| Amiodarone | 150 mg IV over 10 min, then 1 mg/min ×6 h, then 0.5 mg/min | Class I–IV | Variable | Very long | AFib, VT/VF. Hypotension, phlebitis (give central), QT; long-term thyroid / lung / liver toxicity. |
Neuro BP targets: Acute ischemic stroke — if thrombolysis, keep <185/110 before and <180/105 for 24 h; if no reperfusion, permit up to ~220/120. Spontaneous ICH — SBP ~130–140 (avoid <130). Nicardipine or clevidipine preferred; nitroprusside/nitroglycerin/hydralazine can raise ICP.
Neuro.Wiki by Ahmed Koriesh, MD — Educational only, not a substitute for clinical judgement