Vasodilator - pharmacological substances that reduce the tone of smooth muscles of blood vessels, resulting in the increase of the clearance. Tone smooth muscle vascular wall is supported by impulses, constantly coming to the vessels on the sympathetic (adrenergic) nerve fibers. According to this drug may extend the vessels as by weakening the specified activity, and by direct effect on the vascular musculature. Substances that weaken neurogenic vasoconstrictor impulsaciu called neurotropic vasodilating means. Substances that directly affect the muscle fiber, refer to the mechanism of vasodilating agents.
Neurotropic vasodilator divided into substances reflex, Central and peripheral activities. To vasodilating means reflex actions is validol (see), which causes vasodilatation resulting irritation cold receptors mouth. To vasodilating means the Central actions can be attributed reserpine (see), as well as nitrates and nitrites. Neurotropic peripheral vasodilator action include ganglioblokirute funds (see), sympatholytic funds (see), adrenolytic funds (see).
Myotropic vasodilator belong to different classes of chemical compounds. Of them the most important are papaverine (see), Dibazol (see), hloratsizin (see), disproven (see), and derivatives xantina eufillin (see), theobromine (see). These include nitrates and nitrites, which, in addition to the impact on the vasomotor center, have a direct effect on the smooth musculature vessels.
Vasodilator, causing the expansion of the majority of vessels, lowers overall blood pressure. They are mainly used as antihypertensive (see). There are vasodilator, which causes vasodilatation separate organs without significant changes in blood pressure.
Vasodilator, more or less selectively dilates blood vessels of the heart that form the group koronarorasshiryayuschee funds. These include validol, nitrites and nitrates (amyl nitrate, nitroglycerine, ernits, dithranol, nitrosorbid), xantina derivatives (aminophylline, chemical), papaverine, hloratsizin. Koronarorasshirauchee funds are used for cupping the stenocardia (validol, nitroglycerine)and their prevention (ernits, dithranol, nitrosorbid, papaverine, aminophylline, hloratsizin and others).
When violations of cerebral circulation is most often used eufillin. Improve cerebral circulation papaverine, nicotinic acid and some other mechanism vasodilator.
Diseases accompanied by spasms of blood vessels of the extremities (endarteritis, Raynaud's disease and other), use the ganglioblokatory adrenolytic funds, as well as some mechanism vasodilator - papaverine, disproven, angetroffen.
Many vasodilator, especially ganglioblokatory, simpatolitiki, adrainolitiki, can cause orthostatic collapse. To prevent this complication is necessary to avoid sudden changes in body position. Relative contraindications for the use of vasodilators is hypotension.