What is the recommended dose of midodrine (prodrug) for treating hypotension?

Midodrine Dosing for Hypotension

The recommended dose of midodrine for treating hypotension is 10 mg taken three times daily, with doses spaced approximately 4 hours apart during daytime hours. 1

Standard Dosing Protocol

• Starting dose: 2.5-5 mg three times daily 2
• Target dose: 10 mg three times daily 1
• Maximum daily dose: 30-40 mg divided into 3-4 doses 2, 1
• Timing:
  • First dose: Before or upon arising in the morning
  • Second dose: Midday
  • Third dose: Late afternoon (not later than 6 PM) 1

Dose Titration

• Increase dose by 2.5 mg increments weekly until desired response or maximum dose is reached 2
• Doses may be given at 3-hour intervals if required to control symptoms, but not more frequently 1
• Single doses as high as 20 mg have been given to patients, but severe and persistent supine hypertension occurs at a high rate (about 45%) at this dose 1

Special Considerations

Renal Impairment

• For patients with abnormal renal function, start with 2.5 mg doses and titrate cautiously 1

Timing Restrictions

• Do not administer after the evening meal or less than 4 hours before bedtime to reduce the risk of supine hypertension during sleep 1

Efficacy Evidence

• A randomized, double-blind multicenter study demonstrated that 10 mg three times daily significantly improved standing systolic blood pressure at all time points (p<0.001) 3
• The 10 mg dose increased standing systolic blood pressure by 22 mmHg (28%) compared to placebo 4
• A dose-response relationship exists, with higher doses providing greater increases in standing blood pressure 5

Monitoring and Adverse Effects

• Monitor supine and standing blood pressure regularly 1
• Discontinue if supine blood pressure increases excessively 1
• Common adverse effects include:
  • Piloerection and scalp tingling/pruritus (13.5% of patients) 4
  • Supine hypertension (8%) 4
  • Urinary urgency or retention (4%) 4
  • Bradycardia 2
  • GI symptoms 2

Warning for Spinal Cord Injury Patients

• May cause insidious development of urologic adverse effects in patients with spinal cord injury who void spontaneously 6
• Can increase vesical sphincter tone and potentially aggravate detrusor-sphincter dyssynergia 6

Duration of Treatment

• Continue midodrine only in patients who demonstrate symptomatic improvement during initial treatment 1
• The half-life of the active metabolite desglymidodrine is approximately 4 hours 5
• Midodrine is effectively cleared by hemodialysis with a reduced half-life of 1.4 hours in dialysis patients 7

Midodrine has proven efficacy in neurogenic orthostatic hypotension of various etiologies, including Shy-Drager syndrome, idiopathic orthostatic hypotension, diabetic autonomic neuropathy, and Parkinson's disease 8.