What are the management guidelines for postural (orthostatic) hypotension?

Management of Postural (Orthostatic) Hypotension

The management of orthostatic hypotension should prioritize non-pharmacological measures first, followed by pharmacological interventions only when symptoms significantly impair daily activities, with the goal of minimizing symptoms rather than normalizing blood pressure. 1

Definition and Diagnosis

• Orthostatic hypotension is defined as a decrease in systolic blood pressure ≥20 mmHg or diastolic blood pressure ≥10 mmHg within 3 minutes of standing 2, 1
• It can be classified as:
  • Immediate (within 15 seconds of standing)
  • Classical (within 3 minutes)
  • Delayed (after 3 minutes) 2

Treatment Algorithm

Step 1: Non-Pharmacological Interventions

1. Postural Techniques:

   • Physical counter-pressure maneuvers: leg crossing, squatting, and isometric exercises 1, 3
   • Gradual staged movements when changing positions 1
   • Avoid prolonged standing

2. Fluid and Salt Management:

   • Increased salt intake (6-10 g/day) if not contraindicated by other conditions 1, 4
   • Adequate fluid intake (2-2.5 L/day) 1
   • Small, frequent meals to reduce postprandial hypotension 1

3. Mechanical Measures:

   • Compression garments (thigh-high or abdominal) 1
   • Elevate head of bed by 6-9 inches (10-20°) during sleep 1

4. Lifestyle Modifications:

   • Physical activity and exercise to avoid deconditioning 2
   • Avoid alcohol and large meals
   • Avoid hot environments (showers, baths, saunas)

5. Medication Review:

   • Identify and adjust medications that may worsen orthostatic hypotension:
     • Antihypertensives
     • Diuretics
     • Alpha-blockers
     • Vasodilators
     • Tricyclic antidepressants 1

Step 2: Pharmacological Interventions (if non-pharmacological measures are insufficient)

1. First-Line Medications:

   • Midodrine (2.5-10 mg three times daily)

     • Alpha-1 agonist
     • Last dose at least 4 hours before bedtime to prevent supine hypertension
     • FDA-approved for symptomatic orthostatic hypotension 1, 5

   • Droxidopa (100-600 mg three times daily)

     • Last dose at least 4 hours before bedtime
     • FDA-approved for neurogenic orthostatic hypotension 1

2. Second-Line Medications:

   • Fludrocortisone (0.1-0.3 mg daily)

     • Use cautiously due to risk of worsening supine hypertension
     • Contraindicated in heart failure 1, 4

   • Pyridostigmine (30-60 mg three times daily)

     • Less likely to cause supine hypertension
     • Better option for heart failure patients 1

Special Considerations

Monitoring

• Regular blood pressure measurements in both supine and standing positions 1
• Monitor for supine hypertension, especially with pressor medications 1, 5
• Continue medications only for patients who report significant symptomatic improvement 5

Supine Hypertension Management

• Avoid taking medications within 4 hours of bedtime 1, 5
• Sleep with head of bed elevated 1
• For patients with severe supine hypertension, consider shorter-acting antihypertensives at bedtime:
  • Guanfacine or clonidine
  • Shorter-acting calcium blockers (e.g., isradipine)
  • Shorter-acting β-blockers (atenolol, metoprolol tartrate)
  • Enalapril as an alternative 2

Comorbidities

• Diabetes: Use midodrine with caution 2, 5
• Heart Failure: Midodrine, droxidopa, salt tablets, and fludrocortisone may be poorly tolerated; consider pyridostigmine 1
• Renal Impairment: Use midodrine with caution, starting at 2.5 mg; assess renal function prior to use 5
• Hepatic Impairment: Use midodrine with caution 5

Treatment Goals

• The primary goal is to minimize orthostatic symptoms and improve standing time for activities of daily living, not to normalize blood pressure 1, 6
• Aim for improvement in quality of life and reduction in fall risk
• Balance treatment of orthostatic hypotension with management of supine hypertension

Common Pitfalls and Caveats

• Overly aggressive treatment can lead to supine hypertension 5
• Midodrine can cause marked elevation of supine blood pressure (>200 mmHg systolic) 5
• Avoid taking pressor medications within 4 hours of bedtime 1, 5
• Avoid concomitant use of medications that increase blood pressure (phenylephrine, pseudoephedrine, ephedrine, dihydroergotamine) 5
• Cardiac glycosides may enhance or precipitate bradycardia when used with midodrine 5
• Avoid use of MAO inhibitors or linezolid with midodrine 5

By following this structured approach to orthostatic hypotension management, clinicians can effectively minimize symptoms and improve quality of life while reducing the risk of adverse effects such as supine hypertension.