Description medications: Prazosin (Prazosinum)
Prazosin (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, Sinetens; Vasoflex et al.
Crystalline powder white or white with Valium a color shade, very little is soluble in water.
Prazosin is a adrenoblokiruyuschee antihypertensive drug used for hypertension and congestive heart failure.
A feature of prazosin is its selective effect on vascular postsynaptic a 1-adrenergic receptors, which distinguishes it from a conventional adrenoblokatorov, such as phentolamine, and others, at the same time blocking, a 1 and a 2 adrenergic receptors of the blood vessels. Consequently prazosin blocks vasoconstrictive action of the mediator (norepinephrine) without affecting the other of its activity.
Characteristic for the action of prazosin is mainly peripheral vasodilatation. He has at the same time and arterio venorasshiryayuschee action (with some considerable influence on the volume, ie. E. Venous vessels), reduces in connection with the venous blood flow to the heart and facilitates the work of the heart due to a decrease in peripheral resistance, t. E. reduces pre- and afterload on the myocardium. Reduction of cardiac output does not cause drug.
Unlike a conventional adrenoblokatorov tachycardia prazosin, generally does not cause.
The mechanism of vasodilator effect of prazosin is the role of a direct antispasmodic action associated with its inhibitory effect on phosphodiesterase (see. Theophylline).
According to reports, prazosin beneficial effect on lipid parameters of blood serum. The drug also reduces the aggregation of erythrocytes.
Apply prazosin in various forms of hypertension. The antihypertensive effect of prazosin is enhanced in combination with thiazide diuretics, b adrenoblokatorami and other antihypertensive drugs. Due to the decrease of the heart load is also used in the treatment of congestive heart failure.
Prazosin eliminates vasospastic reaction coronary arteries. The drug is often active at the lack of effectiveness of other antihypertensive drugs, including antagonists of calcium ions.
Take prazosin inside regardless of meal times. Start with a small dose - 0.5 - 1 mg, to be taken before going to sleep, then the patient should be in bed for 6 - 8 h. This is necessary due to the possibility of "first dose phenomenon" - postural hypotension until unconscious state (collapse). Especially, this reaction is expressed in the preceding background diuretics.
Further prazosin administered 1 mg of 3 - 4 times daily. Gradually increase the dose, achieving an antihypertensive effect.