Posted by Donna (63.26.214.213) on August 06, 2001 at 22:45:06:
In Reply to: Beta Blockers posted by Shelley on August 06, 2001 at 21:22:36:
Cardioselective beta-blockers slow heart rate and reduce the force of contraction of the heart muscle. These effects can be used to slow a fast heart rate and regulate abnormal rythhms.
They also prevent angina pectoris attacks by reducing work performed by the heart muscle and so the hearts oxygen requirement. High blood pressure is reduced because the rate and force at which the heart pumps blood into the circulation is lowered.
Beta-blockers can reduce the frequency of migraine attacks by preventing the dilation of blood vessels surrounding the brain, which is responsible for the headache.
They block beta-receptors which are specific sites on tissues. There are two types of beta-receptors: those found in heart tissue, and in the lungs, blood vessels and other tissues.
In glaucoma, they lower pressure in the eye by reducing fluid production in the eyeball.