Vasoaktiver

Vasoaktiver refers to substances that influence vascular tone by acting on blood vessels. The term is used in physiology and pharmacology to describe agents that increase or decrease vessel diameter, thereby affecting blood pressure and tissue perfusion.

Vasoactive substances act on vascular smooth muscle or the endothelium. They can cause vasoconstriction by stimulating receptors such as alpha-1 adrenergic receptors, or vasodilation by stimulating beta-2 receptors or by promoting endothelium-derived relaxing factors such as nitric oxide. Some agents act directly on smooth muscle, while others modulate the release of endothelin, prostacyclin, or nitric oxide within the vessel wall.

Vasoaktiver agents are commonly classified as vasoconstrictors or vasodilators. Endogenous examples include adrenaline (epinephrine), noradrenaline, angiotensin II, vasopressin, and endothelin-1. Exogenous vasoactives include phenylephrine, norepinephrine, dopamine, nitroglycerin, and nitroprusside. In clinical practice, these agents are used to manage blood pressure and organ perfusion, such as in shock, anesthesia, or critical care, where careful titration and monitoring are essential.

Potential risks include excessive vasoconstriction leading to tissue ischemia, or excessive vasodilation causing hypotension. Misadministration may cause arrhythmias, reduced organ perfusion, or tissue injury from extravasation. Patients receiving vasoactive therapy are typically monitored with hemodynamic parameters such as mean arterial pressure and sometimes cardiac output, to adjust dosage and minimize adverse effects.