Prazosin

It is a selective competitive antagonist of the classical a1 receptors. It dilates both resistance & capacitance vessels; effect on the former predominating.Cardiovascular reflexes are not appreciably impaired by chronic therapy.

Indications

Moderately potent antihypertensive, CHF & for emergency reduction of BP, BHP, bladder neck dysfunction.

Dosage

Initially 0.5 mg twice daily increasing to 1 mg. 2-3 times daily Maint. 3-20 mg daily in divided doses.

Contra-Indications

CHF due to mechanical obstruction.

Special Precautions

Hepatic impairment, pregnancy, lactation, pheochromocytoma, children below 12 yrs, abrupt withdrawal.

Side Effects

Postural hypotension, headache, drowsiness, dreaming, weakness, palpitation, nasal blockade, dry mouth.

Drug Interactions

Antihypertensive effect enhanced by other antihypertensive drugs & diuretics.