Midodrine Dosage and Usage for Orthostatic Hypotension
Midodrine should be dosed at 5-20 mg three times daily for the treatment of symptomatic orthostatic hypotension that is refractory to non-pharmacological measures. 1
Dosing Recommendations
- Initial dosage: Start with 5 mg three times daily
- Timing: Administer at 8 AM, 1 PM, and no later than 6 PM (to avoid supine hypertension during sleep)
- Dose titration: May increase to 10 mg three times daily based on standing blood pressure response and symptom improvement
- Maximum dose: Up to 20 mg three times daily for severe cases
- Special populations:
- Elderly: Start with lower doses
- Renal impairment: Start with 2.5 mg and monitor closely 1
Administration Guidelines
- Last dose should be taken at least 3-4 hours before bedtime to minimize risk of supine hypertension
- Doses should be spaced approximately 3-4 hours apart based on the half-life of approximately 4 hours for the active metabolite desglymidodrine 2
- Monitor standing blood pressure response, with peak effect occurring approximately 1 hour after administration 2
Treatment Algorithm
First-line approach: Always begin with non-pharmacological measures:
- Increased fluid intake (2-3 liters daily)
- Salt intake (6-9g daily)
- Physical counterpressure maneuvers
- Compression garments 1
When to initiate midodrine:
Contraindications:
- History of hypertension
- Heart failure
- Urinary retention 3
Efficacy and Monitoring
- Midodrine has demonstrated a 43% reduction in syncope recurrence in meta-analyses 3
- Clinical studies show significant improvements in standing systolic blood pressure and orthostatic symptoms 4, 2
- Dose-dependent response has been observed, with higher doses providing greater increases in standing blood pressure 2
Monitoring Parameters
- Standing and supine blood pressure measurements
- Symptom improvement (lightheadedness, syncope, blurred vision, fatigue)
- Signs of urinary retention
- Development of supine hypertension 1
Common Adverse Effects
- Piloerection (goosebumps)
- Urinary hesitancy or retention
- Supine hypertension
- Gastrointestinal disorders 5
Important Cautions
- Urologic adverse effects: Patients with spinal cord injury who void spontaneously may develop progressive urinary retention or worsening of detrusor-sphincter dyssynergia 6
- Supine hypertension: Monitor blood pressure in both supine and standing positions 1
- Timing of doses: Avoid evening doses to prevent nocturnal hypertension 1
Pitfalls to Avoid
- Administering midodrine too close to bedtime
- Focusing solely on blood pressure numbers rather than symptom improvement
- Overlooking non-pharmacological measures before starting medication
- Inadequate monitoring for supine hypertension
- Failure to recognize urinary retention, especially in patients with neurological conditions 1, 6
Midodrine has been shown to be as effective as or more effective than other sympathomimetic agents with fewer adverse effects 5, making it a valuable option for treating orthostatic hypotension when non-pharmacological approaches are insufficient.