Description of the medicine: Prazosinum (Prazosinum)
PRAZOZIN (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, Prazosin, Prazosin, Prazosin, Prazosin, Prazosin; Vasoflex et al.
Crystalline powder, white or white with a creamy tint, very slightly soluble in water.
Prazosin is a hypotensive a-adrenergic blocking drug used in hypertension and congestive heart failure.
The peculiarity of prazosin is its selective effect on vascular postsynaptic a 1 -adrenoreceptors, which distinguishes it from ordinary a-blockers, such as phentolamine, and others blocking at the same time, a 1 and a 2 -adrenoreceptors of blood vessels. As a result, prazosin blocks the vasoconstrictor effect of the mediator (norepinephrine) without affecting other types of its activity.
The characteristic action of prazosin is mainly peripheral vasodilation. It has both an arterio- and veno-expanding effect (with a slightly greater effect on the volumetric, i.e. venous, vessels), reduces in this connection 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. The drug does not cause a decrease in minute volume.
Unlike conventional a-blockers, prazosin tachycardia, as a rule, does not cause.
In the mechanism of the vasodilating effect of prazosin, a direct role is played by the direct antispasmodic effect associated with its inhibitory effect on phosphodiesterase (see Theophylline).
According to reports, prazosin favorably affects serum lipids. The drug also reduces red blood cell aggregation.
Prazosin is used for various forms of arterial hypertension. The antihypertensive effect of prazosin is enhanced when combined with thiazide diuretics, β-blockers and other antihypertensive drugs. Due to the decrease in heart load, it is also used in the treatment of congestive heart failure.
Prazosin eliminates the vasospastic reactions of the coronary arteries. The drug is often active with insufficient effectiveness of other antihypertensive drugs, including calcium ion antagonists.
Take prazosin orally, regardless of the meal time. They start with a small dose - 0.5-1 mg, which should be taken before bedtime, after which the patient should be in bed for 6-8 hours. This is necessary due to the possibility of developing the "phenomenon of the first dose" - postural hypotension up to fainting state (collapse). This reaction is especially pronounced against the background of the previous intake of diuretics.
In the future, prazosin is prescribed 1 mg 3-4 times a day. Gradually increase the dose, achieving a hypotensive effect.