Maximum Oral Labetalol Dose
The maximum recommended oral dose of labetalol for hypertension is 2400 mg daily, though most patients achieve adequate control with 800-1200 mg daily divided into 2-3 doses. 1
Standard Dosing Range
- The typical oral dosing range is 200-800 mg daily, administered twice daily, with titration based on blood pressure response 1
- Most patients with severe hypertension achieve adequate control with doses of 800-1200 mg daily 2, 3
- The American College of Cardiology explicitly states that oral labetalol can be increased up to a maximum of 2400 mg daily according to patient response 1
Evidence from Clinical Practice
The 2400 mg maximum is supported by multiple clinical studies:
- One study of resistant hypertension documented patients receiving 1600-2400 mg daily, with one patient requiring 2200 mg daily plus a diuretic for adequate control 3
- In pregnancy-related hypertension, maximum doses of 1200 mg daily were used successfully without significant maternal or fetal side effects 2
- Doses ranging from 150-450 mg twice daily (300-900 mg total) were effective in third-trimester hypertension 4
Important Clinical Considerations
A critical pitfall is that some patients develop marked postural hypotension at doses that fail to control supine blood pressure 3
- This phenomenon was observed in elderly patients with severe vascular disease who experienced disabling postural hypotension despite inadequate supine blood pressure control 3
- When this occurs, switching to alternative agents rather than further dose escalation is appropriate 3
Dosing Frequency Adjustments
- During pregnancy, labetalol may require three or four times daily dosing due to accelerated drug metabolism, rather than the standard twice-daily regimen 1
- The onset of hypotensive effect occurs within 2 hours of oral administration, with maximal effect by 3 hours 5
- Elimination half-life ranges from 4.3 to 6.9 hours, supporting twice-daily dosing in most non-pregnant patients 4
Contraindications at Any Dose
Labetalol should be avoided regardless of dose in patients with 6, 1:
- Second or third-degree heart block
- Decompensated heart failure
- Bradycardia
- Reactive airways disease or COPD