We saw a
patient today who had been initially followed for management of his
hypertension, but had subsequently developed severe orthostatic hypotension.
Despite treatment, his hypotension was ongoing and significantly affecting his
life. In medicine, we often manage patients with difficult-to-treat
hypertension, however we less often encounter persistent orthostatic
hypotension. I took this opportunity to learn more about the management
strategies for orthostatic hypotension in the ambulatory setting.
Orthostatic
hypotension is defined as a decrease in systolic blood pressure of 20 mmHg or a
decrease in diastolic blood pressure of 10 mmHg within 3 minutes of standing
when compared with the blood pressure in the sitting or supine position. It can
be asymptomatic or symptomatic, causing light-headedness, dizziness, fatigue,
palpitations or syncope. Goals of treatment involve improving hypotension
without excessive supine hypertension and symptomatic relief for the
patient. There are many non-pharmacologic and pharmacologic options
available.
Non-pharmacologic options: These are an
important first-line for neurogenic orthostatic hypotension (ie caused by
autonomic dysfunction).
- Discontinue offending medications: this commonly includes diuretics, antihypertensive agents (primarily sympathetic blockers), nitrates, alpha-adrenergic antagonists, antidepressants.
- Modification of daily activities and patient education: this includes strategies such as getting up slowly, avoiding straining or violent coughing, ensuring adequate hydration and avoiding overheating, raising the head of the bed, and exercise in some cases.
- Compression stockings and abdominal binders: may be helpful in patients who are able to tolerate them.
- Certain physical maneuvers: tensing the legs by crossing them while actively standing on both legs was found to increase blood pressure by 13%.
- Increased salt and water intake: target daily water ingestion of 1.5 - 3 L per day and encourage high sodium foods or prescribe salt tabs.
Pharmacotherapy options: Non-pharmacologic
measures should always be maximized prior to starting pharmacotherapy and must
be continued after initiating medications. A stepwise approach should always be
used with pharmacotherapy, with frequent monitoring.
- Midodrine: is a peripheral selective alpha-1-adrenergic agonist causing both arterial and venous constriction. The dose should be titrated from 2.5 to 10 mg three times a day, with a maximum dose of 40 mg a day. It should not be used in patients with severe heart disease, uncontrolled hypertension or urinary retention. Side effects include: supine hypertension, pilomotor reactions, GI complaints, pruritus and urinary retention.
- Droxidopa: is a norepinephrine (NE) precursor which is converted to NE after ingestion. Dosing starts at 100 mg and can be titrated up to 600 mg three times a day. It is approved for treatment of symptomatic neurogenic orthostatic hypotension associated with Parkinson's, multiple system atrophy, and autonomic neuropathy. Again supine hypertension is a side effect.
- Fludrocortisone: is a synthetic mineralocorticoid which acts by increasing blood volume. Treatment is initiated at a dose of 0.1 mg per day (in the morning) which can be increased to 0.3 mg/day. Side effects include: development of edema, worsening seated or supine hypertension, and hypokalemia (potassium supplementation is usually required).
- Other agents (such as caffeine, erythropoietin, pyridostigmine) have been used in small trials but there is limited evidence to support their use.
This case allowed me to learn more about the different management options for patients with orthostatic hypotension. Although I was previously familiar with a few of the non-pharmacologic methods, I did not know much about the various pharmacologic options. Through this case, I was able to learn more about the medications available, their mechanism of action, indication for their use, dosing protocol, and their side effects!
-MB-
References:
- Kaufmann H, Aminoff MJ (Ed.), Kowey P (Ed.). Treatment of orthostatic and postprandial hypotension. UpToDate. Accessed on March 2 2020 from: https://www-uptodate-com/treatment-of-orthostatic-and-postprandial-hypotension.
- Lanier JB, Mote MB, Clay EC. Evaluation and Management of Orthostatic Hypotension. Am Fam Physician. 2011 Sep 1; 84(5):527-536.
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