Maximum Dose of Oral Labetalol
The maximum daily dose of oral labetalol is 2400 mg per day, administered in divided doses. 1, 2
Dosing Guidelines
Labetalol is a combined alpha and beta blocker that is commonly used in the management of hypertension. The dosing schedule follows a titration approach:
- Initial dose: 100-200 mg twice daily 3
- Titration: Dose can be increased gradually based on blood pressure response
- Maintenance dose: 200-600 mg twice daily 1
- Maximum daily dose: 2400 mg per day in divided doses 1, 2
Clinical Considerations
Efficacy
- Labetalol provides effective blood pressure control at doses ranging from 100-300 mg, with most patients responding to median daily doses of 600 mg 3
- Higher doses may be required for patients with more severe hypertension
- Blood pressure control (defined as diastolic BP <90 mmHg) can be achieved in approximately 72% of patients with mild hypertension using labetalol monotherapy 3
Pharmacokinetics
- Labetalol has a biphasic effect with:
- Initial peak effect at approximately 1 hour after oral administration
- Half-life of approximately 7.5-8 hours 4
- Steady-state plasma concentrations are achieved with both twice-daily and three-times-daily dosing regimens 4
Special Situations
- Hypertensive urgencies: Initial oral dose of 300 mg, with additional 100 mg doses at 2-hour intervals if needed (maximum 500 mg per episode) 5
- Transition from IV to oral therapy: Oral labetalol can effectively maintain blood pressure reductions achieved with intravenous administration 6
Contraindications and Precautions
Labetalol should be used with caution or avoided in patients with:
- Second or third-degree AV block
- Reactive airway disease/asthma
- Decompensated heart failure 2
Monitoring
- Blood pressure should be monitored regularly during dose titration
- Observe for potential side effects including hypotension, dizziness, and bradycardia
- No evidence of blood pressure overshoot when labetalol is abruptly discontinued 3
When prescribing labetalol at higher doses approaching the maximum of 2400 mg daily, careful monitoring is essential to ensure both efficacy and safety, with particular attention to blood pressure response and potential adverse effects.