Alpha Adrenergic Modifiers for Hypertension

Alpha-2-agonists (central acting)

Clonidine

Drowsiness, sedation, dry mouth, fatigue, sexual dysfunction, rebound hypertension with abrupt discontinuance (particularly if doses are high or concomitant beta-blockers are continued), localized skin reaction to clonidine patch; possibly liver damage, Coombs-positive hemolytic anemia with methyldopa

Should be used cautiously in older patients because of orthostatic hypotension

Interferes with measurements of urinary catecholamine levels by fluorometric methods

Should not be combined with an alpha-1-blocker because of a risk of significant orthostatic hypotension.

Clonidine TTS (patch)

Guanfacine

Methyldopa

Alpha-1 blockers

Doxazosin

First-dose syncope, orthostatic hypotension, weakness, palpitations, headache

Should be used cautiously in older patients because of orthostatic hypotension

Relieves symptoms of benign prostatic hyperplasia

Prazosin

Terazosin