guanadrel sulfate /gwan′ədril/ , an antihypertensive agent. 
INDICATIONS: It is prescribed in the treatment of hypertension in patients who do not respond to first-line agents, usually in combination with a diuretic. CONTRAINDICATIONS: Pheochromocytoma, administration of monoamine oxidase inhibitors, frank congestive heart failure, or known sensitivity to this drug prohibits its use. ADVERSE EFFECTS: Among the most serious adverse effects are orthostatic hypotension and syncope.
