What are the guidelines for managing orthostatic hypotension?

Guidelines for Managing Orthostatic Hypotension

The management of orthostatic hypotension should prioritize adequate hydration and salt intake as first-line interventions, followed by pharmacologic therapy with midodrine or fludrocortisone when necessary. 1

Definition and Clinical Impact

• Orthostatic hypotension (OH) is defined as a decrease in blood pressure of ≥20 mmHg systolic or ≥10 mmHg diastolic within 3 minutes of standing from a supine position 2
• OH is associated with significant increases in cardiovascular risk, falls, and up to a 50% increase in relative risk of all-cause mortality 2
• Prevalence is approximately 20% in older adults and 5% in middle-aged adults in community settings 2

First-Line Non-Pharmacological Interventions

Fluid and Salt Management

• Maintain adequate hydration with 2-3 L of fluids per day and 10g of NaCl daily 1
• Rapid cool water ingestion can effectively combat orthostatic intolerance and post-prandial hypotension 1
• Salt supplements and increased dietary salt/electrolyte intake (such as sports drinks) should be encouraged unless contraindicated 1

Physical Countermeasures

• Physical counterpressure maneuvers (PCMs) such as leg crossing and squatting should be encouraged in patients with warning symptoms who can perform them 1
• Abdominal binders or compression stockings (support garments) should be used to reduce venous pooling 1
• Sleeping with the head of the bed elevated (10°) prevents nocturnal polyuria, maintains better fluid distribution, and ameliorates nocturnal hypertension 1

Medication Review

• Identify and discontinue or modify medications that may cause or worsen hypotension 1
• Common culprits include diuretics, vasodilators, and alcohol 1

Pharmacological Management

First-Line Medications

Midodrine

• Midodrine (5-20 mg, three times daily) has been shown to be effective in randomized placebo-controlled trials 1
• Increases standing, sitting, and supine systolic and diastolic blood pressure by approximately 15-30 mmHg at 1 hour after a 10 mg dose 3
• Important precaution: Take the last daily dose 3-4 hours before bedtime to minimize nighttime supine hypertension 3
• Contraindicated in patients with severe cardiac disease, acute renal disease, urinary retention, pheochromocytoma, or thyrotoxicosis 3

Fludrocortisone

• Fludrocortisone (0.1-0.3 mg once daily) stimulates renal sodium retention and expands fluid volume 1
• Effective in combination with head-up sleeping and has shown hemodynamic benefit and symptom reduction 1
• Monitor for supine hypertension, which can be minimized by reducing the dose or decreasing salt intake 3

Special Considerations

Monitoring for Complications

• Evaluate for supine hypertension at the beginning of therapy, especially with midodrine 3
• Monitor renal function prior to and during treatment with midodrine, as desglymidodrine is eliminated via the kidneys 3
• Use caution when combining medications that increase blood pressure (e.g., phenylephrine, pseudoephedrine) 3

Additional Treatment Options

• For refractory cases, consider:
  • Desmopressin for nocturnal polyuria 1
  • Octreotide for post-prandial hypotension 1
  • Pyridostigmine for neurogenic OH 1
  • Erythropoietin in patients with anemia 1

Treatment Algorithm Based on OH Type

1. For all patients with OH:

   • Begin with non-pharmacological measures (hydration, salt, compression garments, PCMs) 1
   • Discontinue or modify causative medications 1

2. If symptoms persist:

   • Add midodrine (starting at 2.5-5 mg three times daily) for immediate relief 1, 3
   • OR fludrocortisone (starting at 0.1 mg daily) for volume expansion 1

3. For refractory cases:

   • Consider combination therapy with both midodrine and fludrocortisone 4
   • Add specialized treatments based on specific clinical features (e.g., octreotide for post-prandial hypotension) 1

Pitfalls and Caveats

• Supine hypertension is a common complication of OH treatment that must be monitored and managed 3
• The last dose of midodrine should be taken at least 3-4 hours before bedtime to avoid nocturnal hypertension 3
• Beta-blockers may be detrimental in dysautonomic syndromes and may enhance bradycardia in cardioinhibitory forms of neurally-mediated syncope 1
• Treatment goals should focus on symptom improvement and quality of life rather than achieving a target blood pressure 5