Clonidine lowers blood pressure by decreasing the levels of certain chemicals in your blood. It is used to treat hypertension (high blood pressure).
Propranolol is used alone or in combination with other medications to treat high blood pressure. It is also used to treat irregular heartbeats, pheochromocytoma (tumor on a small gland near the kidneys), certain types of tremor, and hypertrophic subaortic stenosis (a heart muscle disease). Propranolol is also used to prevent angina (chest pain), migraine headaches, and to improve survival after a heart attack. Propranolol is in a class of medications called beta blockers. It works by relaxing blood vessels and slowing heart rate to improve blood flow and decrease blood pressure.
Nitroglycerin is a vasodilatory drug used primarily to provide relief from anginal chest pain. It is currently FDA approved for the acute relief of an attack or acute prophylaxis of angina pectoris secondary to coronary artery disease.