What is the initial approach to managing orthostatic hypotension?

Initial Management of Orthostatic Hypotension

The first therapeutic approach in symptomatic orthostatic hypotension should consider the exclusion of drugs exacerbating orthostatic hypotension, correction of volume depletion, and implementation of non-pharmacological measures before initiating pharmacotherapy. 1, 2

Step 1: Identify and Address Causative Factors

• Review and modify/discontinue medications that may cause or exacerbate orthostatic hypotension, including alpha-1 blockers (doxazosin, prazosin), centrally-acting antihypertensives (clonidine, methyldopa), diuretics, and vasodilators 2
• Evaluate for volume depletion and correct if present, as this is a common reversible cause of orthostatic hypotension 3, 1
• Assess for underlying conditions that may contribute to orthostatic hypotension, such as diabetes with autonomic neuropathy 3, 1

Step 2: Implement Non-Pharmacological Measures

• Increase fluid intake (≥2 L/day) and salt consumption (10-20 g/day) if not contraindicated by other conditions such as heart failure or hypertension 1, 4
• Recommend smaller, more frequent meals to reduce post-prandial hypotension 1, 5
• Advise acute water ingestion (≥480 mL) for temporary relief of symptoms, with peak effect occurring 30 minutes after consumption 1, 4
• Implement physical counter-maneuvers such as leg-crossing, stooping, squatting, and muscle tensing to help manage symptoms 1, 2
• Recommend gradual staged movements when changing posture to minimize blood pressure drops 1, 2
• Suggest compression garments for the lower extremities and abdomen to reduce venous pooling 4, 5
• Elevate the head of the bed during sleep (by 6-9 inches) to help prevent supine hypertension 1, 6
• Encourage physical activity and exercise to avoid deconditioning 1, 4

Step 3: Pharmacological Management (if non-pharmacological measures fail)

• Consider pharmacotherapy when non-pharmacological measures fail to adequately control symptoms, with the goal of minimizing postural symptoms rather than restoring normotension 1, 5
• First-line medications include:
  • Midodrine (alpha-1 agonist): Starting dose 2.5-5 mg three times daily (with the last dose no later than 6 PM to avoid supine hypertension), can increase to 10 mg three times daily 7
  • Fludrocortisone: Initial dose 0.05-0.1 mg daily with individual titration to 0.1-0.3 mg daily; monitor for adverse effects including supine hypertension, hypokalemia, and edema 3, 5
• For patients with both hypertension and orthostatic hypotension, consider long-acting dihydropyridine calcium channel blockers or RAS inhibitors as they have minimal orthostatic effects 1, 2
• For patients with refractory symptoms, combination therapy with midodrine and fludrocortisone may be considered 3, 5

Monitoring and Follow-up

• Monitor for supine hypertension, especially with midodrine and fludrocortisone therapy 7
• Advise patients to take their last daily dose of midodrine 3-4 hours before bedtime to minimize nighttime supine hypertension 7, 6
• Assess renal function prior to and during treatment, especially in patients with renal impairment 7, 8
• Evaluate treatment efficacy based on symptom improvement rather than normalization of blood pressure measurements 1, 7

Special Considerations

• In diabetic patients with orthostatic hypotension, assess for cardiovascular autonomic neuropathy 3, 1
• Use midodrine with caution in patients with urinary retention problems, as it acts on alpha-adrenergic receptors of the bladder neck 7, 8
• Be cautious when using midodrine concomitantly with other vasoconstrictors, cardiac glycosides, or medications that reduce heart rate 7, 6

By following this algorithmic approach to managing orthostatic hypotension, clinicians can effectively address this condition while minimizing adverse effects and improving patient quality of life.