Treatment of orthostatic hypotension secondary to autonomic failure
What are the most common medications used for the treatment of orthostatic hypotension secondary to autonomic failure?
Fludrocortisone, a potent mineralocorticoid, is the most common agent in use.
Its mechanism of action is increasing of the blood volume by retention of sodium from the kidneys.
Usually 1 to 2 weeks is required to see the effect.
The α 1 -agonist midodrine stimulates both arterial and venous systems without directly affecting the CNS or heart.
This drug is converted to the active agent desglymidodrine and is best used to elevate the daytime blood pressure.
Up to one-fourth of patients may develop supine hypertension, which can best be prevented by taking the last dose at least a few hours before bed time.
A precursor of NE ( l -threo-3,4-dihydroxyphenylserine [ l -DOPS]) can be converted to NE outside of the CNS and improve orthostatic tolerance.
α 2 -Agonists such as clonidine are sometimes used as an adjunctive therapy, but their use is limited by supine hypertension.