Празозин

Prazosin is used for treating mid-to-moderate hypertension. When using this drug, blood pressure is reduced without any significant change in indicators of cardiac function such as frequency, coronary flow, or cardiac output.

ChEBI: A member of the class of piperazines that is piperazine substituted by a furan-2-ylcarbonyl group and a 4-amino-6,7-dimethoxyquinazolin-2-yl group at positions 1 and 4 respectively.

Prazosin is effective in reducing all grades of hypertension. The drug can be administered alone in mild and (in some instances) moderate hypertension.When the hypertension is moderate or severe, prazosin generally is given in combination with a thiazide diuretic and a -blocker. The antihypertensive actions of prazosin are considerably potentiated by coadministration of thiazides or other types of antihypertensive drugs.
Prazosin may be particularly useful when patients cannot tolerate other classes of antihypertensive drugs or when blood pressure is not well controlled by other drugs. Since prazosin does not significantly influence blood uric acid or glucose levels, it can be used in hypertensive patients whose condition is complicated by diabetes mellitus or gout. Prazosin and other -antagonists find use in the management of benign prostatic obstruction, especially in patients who are not candidates for surgery. Blockade of -adrenoceptors in the base of the bladder and in the prostate apparently reduces the symptoms of obstruction and the urinary urgency that occurs at night.

Although less of a problem than with phenoxybenzamine or phentolamine, symptoms of postural hypotension, such as dizziness and light-headedness, are the most commonly reported side effects associated with prazosin therapy. These effects occur most frequently during initial treatment and when the dosage is sharply increased. Postural hypotension seems to be more pronounced during Na deficiency, as may occur in patients on a low-salt diet or being treated with diuretics, - blockers, or both.