How to manage orthostatic hypotension?

Management of Orthostatic Hypotension

Begin with non-pharmacological interventions in all patients, and add fludrocortisone (0.05-0.1 mg daily) or midodrine (2.5-5 mg three times daily) when lifestyle measures fail to control symptoms, with the goal of minimizing postural symptoms rather than normalizing blood pressure. 1

Initial Assessment and Reversible Causes

• Measure blood pressure after 5 minutes of lying/sitting, then at 1 and 3 minutes after standing to confirm orthostatic hypotension (drop ≥20 mmHg systolic or ≥10 mmHg diastolic). 1

• Immediately review and discontinue or switch medications that worsen orthostatic hypotension, particularly diuretics, vasodilators, ACE inhibitors, alpha-blockers, and psychotropic drugs—this is the most frequent cause of orthostatic hypotension. 1

• For patients requiring blood pressure control, switch to long-acting dihydropyridine calcium channel blockers or RAS inhibitors rather than simply reducing doses, as dose reduction alone is insufficient. 1

• Evaluate for volume depletion, anemia, endocrine disorders (adrenal insufficiency, hypothyroidism), and cardiovascular autonomic neuropathy (especially in diabetics). 1

Non-Pharmacological Management (First-Line for All Patients)

Volume expansion strategies:

• Increase fluid intake to 2-3 liters daily unless contraindicated by heart failure. 1
• Increase salt consumption to 6-9 grams daily (approximately 1-2 teaspoons of table salt) if not contraindicated. 2, 1
• Acute water ingestion of ≥480 mL provides temporary relief with peak effect at 30 minutes—useful before standing or activities that provoke symptoms. 1

Postural and mechanical interventions:

• Elevate the head of bed by 10 degrees during sleep to prevent nocturnal polyuria, maintain favorable fluid distribution, and reduce supine hypertension. 1
• Use waist-high compression stockings (30-40 mmHg) and abdominal binders to reduce venous pooling—thigh-high compression alone is insufficient. 2, 1
• Teach physical counter-maneuvers: leg crossing, squatting, stooping, and muscle tensing during symptomatic episodes to acutely raise blood pressure. 2, 1
• Advise gradual staged movements when changing position from lying to sitting to standing. 1

Dietary modifications:

• Eat smaller, more frequent meals to reduce post-prandial hypotension, which can drop blood pressure by 20+ mmHg within 1-2 hours after eating. 2, 1
• Avoid large carbohydrate loads that exacerbate post-prandial hypotension. 2

Exercise recommendations:

• Encourage regular physical activity, especially swimming and leg/abdominal muscle exercises, to prevent deconditioning which worsens orthostatic intolerance. 2, 1

Pharmacological Management (When Non-Pharmacological Measures Fail)

First-Line Medications

Fludrocortisone (mineralocorticoid):

• Start with 0.05-0.1 mg once daily, titrate to 0.1-0.3 mg daily based on response (maximum 1.0 mg daily). 1
• Mechanism: increases plasma volume through sodium retention and enhances vessel wall responsiveness to catecholamines. 1
• Monitor for supine hypertension (most important limiting factor), hypokalemia, peripheral edema, and heart failure exacerbation. 1
• Contraindicated in active heart failure, severe renal disease, and pre-existing supine hypertension. 1
• Check electrolytes periodically due to mineralocorticoid-induced potassium wasting. 1
• Evidence quality is limited to small, short-term trials with very low-certainty evidence. 1

Midodrine (alpha-1 adrenergic agonist):

• Start with 2.5-5 mg three times daily, can increase to 10 mg three times daily if needed. 1, 3
• Mechanism: increases vascular tone through arteriolar and venous constriction without direct cardiac or CNS effects. 3
• Increases standing systolic BP by 15-30 mmHg for 2-3 hours after dosing. 1, 3
• Avoid the last dose after 6 PM to prevent supine hypertension during sleep. 1, 3
• Use with caution in older males due to potential urinary retention from alpha-adrenergic effects on bladder neck. 1, 3
• Monitor for supine hypertension, bradycardia, and urinary retention. 3
• Avoid concomitant use with other vasoconstrictors (phenylephrine, pseudoephedrine, ephedrine) and MAO inhibitors. 3

Combination Therapy

• For non-responders to monotherapy, combine midodrine and fludrocortisone for synergistic effect. 1

Alternative and Adjunctive Agents

Droxidopa:

• FDA-approved for neurogenic orthostatic hypotension in Parkinson's disease, pure autonomic failure, and multiple system atrophy. 1
• May reduce falls in these populations. 1

Pyridostigmine:

• Consider for refractory orthostatic hypotension in elderly patients who have not responded to first-line treatments. 1
• Favorable side effect profile compared to fludrocortisone, though common side effects include nausea, vomiting, abdominal cramping, and sweating. 1

Desmopressin:

• Consider for patients with nocturnal polyuria causing morning orthostatic hypotension. 2, 1

Erythropoietin:

• Consider for patients with anemia and severe autonomic neuropathy. 2, 1

Treatment Goals and Monitoring

• The therapeutic objective is minimizing postural symptoms, NOT restoring normotension—attempting to normalize blood pressure often causes intolerable supine hypertension. 1

• Balance the benefits of increasing standing blood pressure against the risk of supine hypertension, which can cause end-organ damage. 1

• Follow-up schedule: early review at 24-48 hours after medication initiation, intermediate at 1-2 weeks, and late at 3-6 months. 1

• Measure both standing and supine blood pressures at each visit to detect supine hypertension. 1

• Continue midodrine only in patients who report significant symptomatic improvement after initiation, as clinical benefits beyond blood pressure elevation have not been definitively established. 3

Critical Pitfalls to Avoid

• Do not simply reduce doses of offending antihypertensives—switch to alternative agents entirely (e.g., long-acting dihydropyridine CCBs or RAS inhibitors for hypertension management). 1

• Do not add salt to water for acute relief—paradoxically, salt water produces a smaller pressor response than plain water alone due to gastrointestinal osmolality effects on sympathetic activation. 4

• Do not allow patients to become fully supine if on pressor agents—sleeping with head elevated prevents dangerous supine hypertension. 1, 3

• Do not use fludrocortisone in patients with heart failure or significant cardiac dysfunction—volume expansion will worsen their condition. 1

• Do not combine midodrine with cardiac glycosides, beta-blockers, or other bradycardic agents without careful monitoring—risk of severe bradycardia and AV block. 3

• Warn patients to avoid over-the-counter cold remedies and diet aids containing sympathomimetics that can potentiate midodrine's pressor effects. 3