Oral Labetalol Dosing for Hypertension
For chronic hypertension management, start labetalol at 100 mg twice daily and titrate upward in 100 mg increments every 2-3 days based on blood pressure response, with a usual maintenance dose of 200-400 mg twice daily and a maximum of 2400 mg daily. 1
Initial Dosing
- Begin with 100 mg twice daily whether used alone or added to a diuretic regimen 1
- The full antihypertensive effect occurs within 1-3 hours of each dose, allowing office-based assessment of tolerability 1
- Measure blood pressure approximately 12 hours after dosing at follow-up visits to determine if further titration is needed 1
Titration Protocol
- Increase by 100 mg twice daily every 2-3 days using standing blood pressure as the primary indicator 1
- Do not exceed 200 mg twice daily per titration increment 1
- If side effects (nausea or dizziness) occur with twice-daily dosing, divide the same total daily dose into three times daily to improve tolerability 1
Maintenance Dosing
- Most patients achieve control with 200-400 mg twice daily (400-800 mg total daily) 1
- The typical effective range is 200-800 mg daily administered twice daily 2
- Patients with severe hypertension may require 1200-2400 mg per day with or without thiazide diuretics 1
- The absolute maximum dose is 2400 mg daily 3
Special Population Adjustments
Elderly Patients
- Start at 100 mg twice daily, same as general population 1
- Titrate upward in 100 mg increments as needed 1
- Most elderly patients achieve control with 100-200 mg twice daily due to slower drug elimination 1
Pregnancy
- Labetalol is first-line for hypertension in pregnancy 2
- May require three or four times daily dosing (rather than twice daily) due to accelerated drug metabolism during pregnancy 2, 3
Combination Therapy Considerations
- When adding a diuretic, expect an additive antihypertensive effect that may necessitate labetalol dose reduction 1
- Optimal doses are usually lower when combined with diuretics 1
- When transferring from other antihypertensives, introduce labetalol as recommended while progressively decreasing the existing therapy 1
Absolute Contraindications (At Any Dose)
- Second or third-degree heart block 3
- Decompensated heart failure 3
- Bradycardia 3
- Reactive airways disease or COPD 3
Clinical Pearls
- Research demonstrates that 72% of patients with mild hypertension achieved control (diastolic BP <90 mmHg) on labetalol monotherapy at median doses of 600 mg daily 4
- For hypertensive urgencies in the emergency department, oral doses of 100-300 mg effectively reduced blood pressure in 58-75% of patients within 2 hours 5
- No blood pressure overshoot occurs with abrupt discontinuation 4
- Side effects typical of beta-blockers are less prominent with labetalol at usual antihypertensive doses of 100-1200 mg twice daily 6