Midodrine Dosing for Orthostatic Hypotension
The recommended dose of midodrine for treating orthostatic hypotension is 10 mg three times daily, with doses spaced approximately 4 hours apart during daytime hours. 1
Dosing Protocol
- Starting dose: 10 mg three times daily
- Timing: Morning, midday, and late afternoon (not later than 6 PM)
- Dosing intervals: Approximately every 4 hours
- Maximum daily dose: 30 mg (10 mg × 3 doses)
- Alternative dosing: May be given at 3-hour intervals if needed to control symptoms, but not more frequently
Important Administration Guidelines
- First dose should be taken shortly before or upon arising in the morning
- Last dose should be taken in late afternoon (not later than 6 PM)
- Midodrine should not be given after the evening meal or less than 4 hours before bedtime to reduce the risk of supine hypertension 2, 1
- Doses should be taken during daytime hours when the patient needs to be upright for daily activities
Special Population Considerations
- Renal impairment: Start with 2.5 mg doses in patients with abnormal renal function 1
- Elderly patients: No dose adjustment necessary based on age alone, as blood levels are similar in patients over and under 65 years 1
Monitoring and Dose Adjustments
- Regular monitoring of supine and standing blood pressure is essential
- Discontinue midodrine if supine blood pressure increases excessively
- The therapeutic goal is to minimize postural symptoms rather than to restore normotension 2
- Single doses as high as 20 mg have been given but cause severe supine hypertension in about 45% of patients 1, 3
Clinical Effects
- Standing systolic blood pressure typically increases by 15-30 mmHg at 1 hour after a 10 mg dose 1
- Effects may persist for 2-3 hours after administration 1
- The active metabolite (desglymidodrine) has a half-life of approximately 3-4 hours 1, 3
Common Adverse Effects
- Supine hypertension (most significant risk)
- Pilomotor reactions (goosebumps, scalp tingling)
- Urinary retention or urgency
- Bradycardia
- Gastrointestinal symptoms 2, 1, 4
Cautions and Contraindications
- Patients with spinal cord injury who void spontaneously may develop urologic adverse effects 4
- Avoid use in patients with severe cardiac disease, acute renal disease, urinary retention, pheochromocytoma, or thyrotoxicosis
- Use with caution in patients with prostatic hypertrophy
Alternative Treatments
If midodrine is not tolerated or contraindicated, consider:
- Fludrocortisone (0.05-0.1 mg daily, titrated to 0.1-0.3 mg daily) 2
- Droxidopa (another FDA-approved medication for neurogenic orthostatic hypotension) 2
- Non-pharmacological measures (increased salt/fluid intake, compression garments, physical counter-maneuvers) 2, 5
Midodrine has been shown to be effective in multiple randomized controlled trials, demonstrating significant improvements in standing blood pressure and symptoms of orthostatic hypotension compared to placebo 6, 3, 7.