Labetalol
Brand names: Trandate, Normodyne
Class: ❤️ Beta-Blockers
The AANP exam tests labetalol as the go-to antihypertensive in pregnancy and one of the workhorses of hypertensive emergency. It blocks alpha-1 and beta-1/beta-2 receptors, lowering blood pressure without dropping cardiac output sharply. In pregnancy-induced hypertension and preeclampsia, labetalol is first-line alongside nifedipine and methyldopa — ACE inhibitors and ARBs are contraindicated. In the hospital, IV labetalol is a standard agent for hypertensive urgency and emergency. Avoid in asthma (non-selective beta blockade), severe bradycardia, and decompensated heart failure. Resistant outpatient hypertension is another use, particularly when both rate and pressure need control. Watch for orthostasis with the alpha component.
✅ Indications
Pregnancy-induced HTN, hypertensive emergency, resistant HTN.
⚙️ Mechanism of Action
Non-selective β + α₁-blocker.
📏 Dosing
PO: 100–400 mg BID. IV: 20 mg bolus, then 40–80 mg q10 min (max 300 mg).
🚫 Contraindications
Asthma (non-selective), severe bradycardia, decompensated HF.
⚠️ Adverse Effects
Orthostatic hypotension, bradycardia, fatigue, scalp tingling (unique).
🔬 Monitoring
BP (supine + standing), HR; fetal monitoring in pregnancy.
💎 Board Pearls
- 🤰 GOLD STANDARD for HTN in pregnancy (+ nifedipine, methyldopa).
- 🆘 Go-to IV drip for hypertensive emergency outside pregnancy too.
Related Drugs in This Class
- Metoprolol — Lopressor (tartrate), Toprol-XL (succinate)
- Carvedilol — Coreg
- Propranolol — Inderal
Sources
Ready to practice?
1,500+ AANP-style questions with rationales — free trial.