Vasoactives

Vasoactives, or vasoactive drugs, are substances that influence the tone of vascular smooth muscle, thereby changing vascular resistance and blood pressure. They include endogenous mediators such as norepinephrine, epinephrine, angiotensin II, and endothelin, as well as pharmaceutical agents given to patients. Vasoactives are used to manage hemodynamics in conditions like shock, heart failure, and during anesthesia or major surgery, with the goal of preserving adequate tissue perfusion.

They are broadly categorized into vasopressors, which constrict blood vessels and raise blood pressure, and vasodilators, which relax vessels to lower resistance. Common vasopressors include norepinephrine, epinephrine, phenylephrine, dopamine, vasopressin, and angiotensin II. Common vasodilators include nitroprusside, nitroglycerin, hydralazine, clevidipine, and nicardipine. Some agents have context-dependent effects or broader actions on heart rate and contractility.

Clinical use requires careful titration and monitoring, typically via intravenous infusion in hospital settings. Physicians monitor mean arterial pressure, heart rate, urine output, and signs of organ perfusion. Potential risks include excessive vasoconstriction causing tissue ischemia, arrhythmias, hypotension from over-vasodilation, and injection-site injury from extravasation. Dosing and choice depend on the patient’s condition, comorbidities, and concurrent therapies.