Vasodilators are a class of drugs that dilate, relax or widen blood vessels (mainly the arterioles) results from relaxation of smooth muscle cells, which allows blood to flow more easily that causes blood pressure to drop.
Vasodilators are used to treat or prevent hypertension, heart failure, preeclampsia (high blood pressure during pregnancy), angina, and pulmonary hypertension. Vasodilators are often used in combination with other drugs and are rarely used alone.
There are different types of vasodilators, they are:
- Arterial dilators (mainly affect the arteries): They reduce arterial pressure by decreasing systemic vascular resistance.
- Venous dilators (mainly affect the veins): They reduce venous pressure, which reduces preload on the heart thereby decreasing cardiac output.
- Mixed dilators (affect veins and arteries): They act on both arteries and veins, and therefore termed as mixed or balanced dilators.
Commonly prescribed vasodilator medications on the market, include:
- Arterial dilator drugs are hydralazine hydrochloride (brand name: Apresoline) and Minoxidil (brand name: Loniten). Its side effects are reflex tachycardia, anorexia, and hypotension.
- Venous dilator drugs are organic nitrates (such as nitroglycerin, isosorbidenmono-/di-nitrate, and sodium nitroprusside). Its side effects are hypotension, headaches, rebound hypertension on discontinuation.
- Combination dilator drugs are Nitroprusside, Pimobendan, and Angiotensin converting enzyme (ACE) inhibitors.
Who should avoid vasodilators?
Avoid vasodilators, if you are taking bisulfates, diuretics (water pills), insulin, phenytoin, corticosteroids, estrogen, warfarin, or progesterone. Avoid vasodilators, if you are pregnant, nursing women, diabetes, heart disease, or uremia (build-up of waste in your blood).
What are the side effects of vasodilators?
Rapid heartbeat (tachycardia), palpitations, edema, nausea, vomiting, stomach upset, dizziness, flushing, headache, growth in body hair, joint pain, swelling around the eyes, aches/pains in the joints, and chest pain.
What are the warning signs of vasodilators?
Consult a doctor immediately if having; fever, fast heartbeat, fainting, chest pain, breathing problems, sudden weight gain.