How is postural hypotension managed?

Management of Postural Hypotension

Begin with non-pharmacological interventions including increased fluid intake (2-3 liters daily) and salt consumption (6-9g daily), combined with physical counter-maneuvers and compression garments; if symptoms persist despite these measures, initiate midodrine 2.5-5mg three times daily as first-line pharmacological therapy, with the last dose at least 3-4 hours before bedtime to prevent supine hypertension. 1

Initial Assessment and Reversible Causes

• Immediately review and discontinue or switch medications that worsen orthostatic hypotension, particularly diuretics, alpha-1 blockers, ACE inhibitors, and calcium channel blockers—switching to alternative therapy is essential, not simply dose reduction 1
• Drug-induced autonomic failure is the most frequent cause of orthostatic hypotension 1
• Assess for volume depletion, alcohol use (causes both direct CNS effects and central volume depletion), and endocrine disorders 2, 1
• Measure blood pressure after 5 minutes of lying/sitting, then at 1 and 3 minutes after standing to confirm the diagnosis (≥20 mmHg systolic or ≥10 mmHg diastolic drop) 2, 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 intake to 6-9g 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 1

Physical Counter-Maneuvers:

• Teach leg crossing, squatting, stooping, and muscle tensing during symptomatic episodes—particularly effective in patients under 60 years with prodromal symptoms 1
• These maneuvers should be implemented at the first sign of symptoms 1

Compression Garments:

• Use waist-high compression stockings (30-40 mmHg) and abdominal binders to reduce venous pooling 1
• Compression must extend to the abdomen to be effective 1

Lifestyle Modifications:

• Elevate the head of the bed by 10 degrees during sleep to prevent nocturnal polyuria, maintain favorable fluid distribution, and ameliorate nocturnal hypertension 1
• Eat smaller, more frequent meals to reduce post-prandial hypotension 2, 1
• Encourage physical activity and exercise to avoid deconditioning, which exacerbates orthostatic intolerance 2, 1
• Implement gradual staged movements with postural changes 1

Pharmacological Management (When Non-Pharmacological Measures Fail)

The therapeutic goal is minimizing postural symptoms and improving functional capacity, NOT restoring normotension—aggressive blood pressure targets may worsen supine hypertension. 1

First-Line: Midodrine

• Midodrine has the strongest evidence base among pressor agents, with three randomized placebo-controlled trials demonstrating efficacy 1
• Start at 2.5-5mg three times daily 1, 3
• Mechanism: alpha-1 adrenergic agonist that increases vascular tone through arteriolar and venous constriction 1
• Can increase standing systolic BP by 15-30 mmHg for 2-3 hours 1
• Critical: Last dose must be at least 3-4 hours before bedtime to prevent supine hypertension during sleep 1, 3
• FDA-approved specifically for symptomatic orthostatic hypotension 3
• Use cautiously in older males due to potential urinary retention (acts on alpha-adrenergic receptors of bladder neck) 3
• May cause slight vagal-mediated heart rate slowing, but benefits usually outweigh this concern 1

Second-Line: Fludrocortisone

• Add if midodrine provides insufficient symptom control 1
• Start at 0.05-0.1mg once daily, titrate individually to 0.1-0.3mg daily 2, 1
• Mechanism: mineralocorticoid that increases plasma volume through sodium retention and vessel wall effects 2, 1
• Monitor for supine hypertension (most important limiting factor), hypokalemia, congestive heart failure, and peripheral edema 2, 1
• Avoid in patients with active heart failure, significant cardiac dysfunction, severe renal disease, or pre-existing supine hypertension 1
• Check electrolytes periodically due to potassium wasting 1
• Evidence quality is limited, with only very low-certainty evidence from small, short-term trials 4

Alternative: Droxidopa

• FDA-approved for neurogenic orthostatic hypotension 2, 1
• Particularly effective for Parkinson disease, pure autonomic failure, and multiple system atrophy 1
• May reduce falls in these populations 1

Refractory Cases: Pyridostigmine

• Consider for elderly patients refractory to other treatments 1
• Favorable side effect profile compared to alternatives like fludrocortisone 1
• Common side effects include nausea, vomiting, abdominal cramping, sweating, salivation, and urinary incontinence 1

Combination Therapy

• For non-responders to monotherapy, consider combining midodrine and fludrocortisone 1
• Balance benefits against supine hypertension risk—avoid combining multiple vasoconstrictors without careful blood pressure monitoring 1

Special Considerations for Supine Hypertension

• Supine blood pressure tends to be much higher in patients with orthostatic hypotension, often requiring treatment 2
• Use shorter-acting antihypertensives at bedtime that affect baroreceptor activity: guanfacine, clonidine, shorter-acting calcium blockers (isradipine), or shorter-acting β-blockers (atenolol, metoprolol tartrate) 2
• Alternatives include enalapril if patients cannot tolerate preferred agents 2
• Monitor for end-organ damage from nocturnal hypertension (left ventricular hypertrophy, coronary heart disease, flash pulmonary edema, heart failure, renal failure, stroke) 2

Monitoring and Follow-Up

• Early review at 24-48 hours after medication initiation 1
• Intermediate follow-up at 1-2 weeks to assess standing heart rate, blood pressure, and symptom improvement 1
• Monitor for both symptomatic improvement and development of supine hypertension 1
• Continue treatment only for patients who report significant symptomatic improvement 3
• Patients experiencing signs of bradycardia (pulse slowing, increased dizziness, syncope, cardiac awareness) should discontinue midodrine and be re-evaluated 3

Critical Pitfalls to Avoid

• Do NOT simply reduce doses of offending medications—switch to alternative therapy entirely 1
• Do NOT take midodrine if planning to be supine for any length of time 3
• Do NOT use cardiac pacing for orthostatic hypotension with bradycardia unless there is documented intrinsic sinus node dysfunction independent of postural changes 1
• Avoid over-the-counter cold remedies and diet aids that can elevate blood pressure and potentiate midodrine's pressor effects 3
• Do NOT target arbitrary blood pressure values—focus on symptom improvement and functional status 5