Orthostatic hypotension

An independent predictor of mortality and the cause of significant morbidity associated with falls.

A common problem in frail older people. Orthostatic hypotension-related hospitalisations increase markedly with age.

Common causes include drugs (e.g., alpha-blockers, including tamsulosin [used for treating conditions such as benign prostatic hypertrophy]), diseases causing peripheral neuropathy (e.g., diabetes mellitus), and Parkinson's disease.

Primary neurodegenerative disorders of the autonomic nervous system (pure autonomic failure, and multiple system atrophy or Shy-Drager syndrome) are less common, but cause severe orthostatic hypotension.

Acute or subacute onset should suggest an autoimmune or paraneoplastic disorder.

Treatment consists of addressing any underlying pathology, when possible, followed by non-pharmacological countermeasures (e.g., liberalisation of salt intake, use of abdominal binders or compression stockings). Volume expansion (using mineralocorticoid therapy), short-acting vasopressors, or noradrenaline (norepinephrine) precursor therapy with droxidopa are adjunctive therapies when non-pharmacological measures are insufficient.

Orthostatic hypotension is defined as a fall in systolic blood pressure of at least 20 mmHg (at least 30 mmHg in patients with hypertension) and/or a fall in diastolic blood pressure of at least 10 mmHg within 3 minutes of standing. It becomes clinically significant if it is accompanied by symptoms of cerebral hypoperfusion, which can lead to syncope and falls. This monograph concentrates on orthostatic hypotension caused by autonomic problems.