What is the recommended dose of labetalol (beta blocker) for treating hypertension?

Labetalol Dosing for Hypertension

For hypertension treatment, oral labetalol is typically initiated at 100 mg twice daily, with titration in 100 mg increments every 2-3 days to a usual maintenance dose of 200-400 mg twice daily, though severe hypertension may require 1,200-2,400 mg daily. 1

Oral Labetalol Dosing

• Initial dose: 100 mg twice daily (whether used alone or with a diuretic) 1
• Titration: Increase by 100 mg twice daily every 2-3 days based on standing blood pressure 1
• Usual maintenance dose: 200-400 mg twice daily 1
• Severe hypertension: May require 1,200-2,400 mg daily (with or without thiazide diuretics) 1
• If side effects occur with twice-daily dosing, the same total daily dose administered three times daily may improve tolerability 1
• Elderly patients: May require lower maintenance dosage (typically 100-200 mg twice daily) due to slower elimination 1

Intravenous Labetalol for Hypertensive Emergencies

For Non-Stroke Hypertensive Emergencies:

• Initial dose: 0.3-1.0 mg/kg (maximum 20 mg) slow IV injection every 10 minutes 2
• Alternative approach: 0.4-1.0 mg/kg/h IV infusion up to 3 mg/kg/h 2
• Maximum cumulative dose: 300 mg (can be repeated every 4-6 hours) 2

For Ischemic Stroke Patients Not Eligible for Thrombolytic Therapy:

• For systolic BP >220 mmHg or diastolic 121-140 mmHg: Labetalol 10-20 mg IV over 1-2 minutes 2
• May repeat or double dose every 10 minutes (maximum dose 300 mg) 2
• Goal: 10-15% reduction in blood pressure 2

For Ischemic Stroke Patients Eligible for Thrombolytic Therapy:

• Pre-treatment (systolic >185 mmHg or diastolic >110 mmHg): Labetalol 10-20 mg IV over 1-2 minutes (may repeat once) 2
• During/after treatment:
  • For systolic >230 mmHg or diastolic 121-140 mmHg: Labetalol 10 mg IV over 1-2 minutes 2
  • May repeat or double every 10 minutes to maximum 300 mg or start labetalol drip at 2-8 mg/min 2
  • For systolic 180-230 mmHg or diastolic 105-120 mmHg: Labetalol 10 mg IV over 1-2 minutes 2
  • May repeat or double every 10-20 minutes to maximum 300 mg or start labetalol drip at 2-8 mg/min 2

Special Considerations

• Labetalol is particularly useful in hypertensive emergencies with hyperadrenergic states 2
• Contraindicated in reactive airways disease or chronic obstructive pulmonary disease 2
• May worsen heart failure and should not be given in patients with second or third-degree heart block or bradycardia 2
• For pregnant patients with hypertension, labetalol is considered safe with no evidence of adverse effects in mothers or babies 2
• When transferring from other antihypertensive drugs, introduce labetalol as recommended and progressively decrease the dosage of existing therapy 1

Monitoring and Efficacy

• Full antihypertensive effect is usually seen within 1-3 hours of initial dose or dose increment 1
• For hypertensive emergencies, monitor blood pressure closely to prevent "overshoot" hypotension 3
• In hypertensive urgencies, oral doses of 100-300 mg have shown similar efficacy in reducing blood pressure within 2-4 hours 4
• When diuretics are added, an additive antihypertensive effect can be expected, potentially necessitating labetalol dosage adjustment 1