What is the initial approach to managing orthostatic hypotension?

Initial Approach to Managing Orthostatic Hypotension

The first therapeutic approach in symptomatic orthostatic hypotension should include identifying and discontinuing medications that exacerbate orthostatic hypotension, correcting volume depletion, and implementing non-pharmacological measures before considering pharmacotherapy. 1, 2

Initial Evaluation and Diagnosis

• Orthostatic hypotension is defined as a decrease in blood pressure of ≥20 mmHg systolic or ≥10 mmHg diastolic within 3 minutes of standing 3
• Testing should include measuring blood pressure after 5 minutes of sitting/lying and then 1 and/or 3 minutes after standing 1
• Identify medications that may cause or worsen orthostatic hypotension:
  • Alpha-1 blockers (doxazosin, prazosin, terazosin) 2
  • Centrally-acting antihypertensives (clonidine, methyldopa, guanfacine) 2
  • Diuretics, particularly when causing volume depletion 2
  • Vasodilators (hydralazine, minoxidil) 2
  • Over-the-counter medications like cold remedies and diet aids 4

Non-Pharmacological Management (First-Line)

• Increase fluid and salt intake if not contraindicated by other conditions 1, 5
• Implement physical counter-maneuvers:
  • Leg-crossing, stooping, squatting, and tensing muscles 1, 2
  • Gradual staged movements with postural change 1, 2
• Acute water ingestion (≥480 mL) for temporary relief, with peak effect occurring 30 minutes after consumption 1
• Recommend smaller, more frequent meals to reduce post-prandial hypotension 1, 5
• Encourage physical activity and exercise to avoid deconditioning 1
• Elevate the head of the bed during sleep to prevent supine hypertension 1
• Use compression garments to reduce venous pooling 5, 3

Pharmacological Management (When Non-Pharmacological Measures Fail)

• Consider pharmacological treatment when non-pharmacological measures fail to adequately control symptoms 1

• First-line medications include:

  • Midodrine (alpha-1 agonist):
    • Dosing: Start with 2.5-5 mg three times daily (last dose no later than 6 PM) 4
    • Increases standing systolic BP by 15-30 mmHg at 1 hour after a 10 mg dose 4
    • Monitor for supine hypertension (BP >200 mmHg systolic) 4
  • Fludrocortisone:
    • Initial dose should be 0.05–0.1 mg daily with individual titration to 0.1–0.3 mg daily 6
    • Acts through sodium retention and vessel wall effects 6
    • Monitor for adverse effects: supine hypertension, hypokalemia, congestive heart failure, and peripheral edema 6

• For non-responders to monotherapy, consider combination of midodrine and fludrocortisone 6

Special Considerations

• For patients with both hypertension and orthostatic hypotension, consider long-acting dihydropyridine calcium channel blockers or RAS inhibitors as first-line therapy 1, 2
• In diabetic patients with orthostatic hypotension, assess for cardiovascular autonomic neuropathy 1
• Use midodrine cautiously in patients with:
  • Urinary retention problems 4
  • Concomitant use of cardiac glycosides, psychopharmacologic agents, or beta blockers 4
  • Renal impairment (start with 2.5 mg) 4
  • Hepatic impairment 4

Monitoring and Follow-up

• Monitor for supine hypertension, especially with pharmacological treatment 4
• Advise patients to discontinue medication immediately if supine hypertension persists 4
• Continue treatment only for patients who report significant symptomatic improvement 4
• Carefully monitor blood pressure when midodrine is used with other vasoconstrictors 4

Treatment Algorithm

1. Identify and discontinue medications that may cause or worsen orthostatic hypotension 2
2. Implement non-pharmacological measures (increased fluid/salt intake, physical counter-maneuvers) 1, 5
3. If symptoms persist, initiate pharmacotherapy with either midodrine or fludrocortisone 6, 1
4. For inadequate response to monotherapy, consider combination therapy 6
5. Continue to monitor for adverse effects, particularly supine hypertension 4

Remember that the goal of treatment is minimizing postural symptoms rather than restoring normotension 1, with emphasis on improving quality of life and reducing falls or syncope 3.