Medication Description: Prazosin (Prazosinum)
Prazosinum (Prazosinum). 1- (4-Amino-6, 7-dimethoxy-2-quinazolyl) -4- (2-furoyl) piperazine hydrochloride.
Synonyms: Adverzuten, Deprazolin, Minipress, Pratsiol, Adversuten, Decliten, Deprazolin, Duramipress, Eurex, Furazosin-hydrochloride, Hypovase, Minipress, Orbisan, Patsolin, Peripress, Pratsiol, Prazac, Prazopress, Praz os ios, Patsolin, Peripress, Praziol, Prazi, Prazos, Pizolin, Peripress Vasoflex et al.
Crystalline powder of white or white with a creamy shade of color, very little soluble in water.
Prazosin is a hypotensive a-adrenergic blocking drug used in hypertension and congestive heart failure.
A feature of prazosin is its selective effect on vascular postsynaptic a 1 -adrenoreceptors, which distinguishes it from ordinary a-blockers, such as phentolamine, and others that block simultaneously, a 1 and a 2 -adrenoreceptors of blood vessels. As a result, prazosin blocks the vasoconstrictor action of the mediator (noradrenaline) without affecting other types of its activity.
Characteristic of prazosin is mainly peripheral vasodilation. It has both arterio-and venorasshiruyuschee effect (with a somewhat large effect on the bulk, ie, venous, blood vessels), in connection with this reduces the venous blood flow to the heart and facilitates the work of the heart due to a decrease in peripheral resistance, i.e. reduces pre- and afterload on the myocardium. Reducing the minute volume of the drug does not cause.
Unlike conventional a-blockers, prazosin does not usually cause tachycardia.
In the mechanism of the vasodilating effect of prazosin, a direct antispasmodic action associated with its inhibitory effect on phosphodiesterase plays a certain role (see. Theophylline).
According to available data, prazosin has a positive effect on serum lipid levels. The drug also reduces erythrocyte aggregation.
Prazozin is used in various forms of hypertension. The hypotensive effect of prazosin is enhanced when combined with thiazide diuretics, b -blockers and other antihypertensive drugs. In connection with the reduction of the load on the heart is also used in the treatment of congestive heart failure.
Prazosin eliminates vasospastic reactions of the coronary arteries. The drug is often active with insufficient efficacy of other antihypertensive drugs, including calcium ion antagonists.
Take prazosin inside regardless of meal times. Begin with a small dose of 0.5 to 1 mg, which should be taken at bedtime, after which the patient should stay in bed for 6 to 8 hours. This is necessary in connection with the possibility of the development of the “first dose phenomenon” - postural hypotension up to fainting condition (collapse). This reaction is especially pronounced on the background of prior diuretic administration.
In the future, prazozin is prescribed in 1 mg 3-4 times a day. Gradually increase the dose, achieving a hypotensive effect.