What is a beta-blocker?
Beta blocker antagonizes another neurohormone in the body called norepinephrine, which is related to the hyperactivity of the sympathetic nervous system. And like the other neurohormones like aldosterone, like angiotensin II, norepinephrine also has a whole slew of deleterious effects on the cardiac myocyte, on the muscle function, on the vascular function. And in patients who have coronary artery disease, or have myocardial infarction or congestive heart failure, it has been shown that if you were to give beta blockers to these patients, you’d reduce their mortality risk.
Beta-blockers end in -ol. For example: Atenolol, Propanolol or Carvedilol. Beta-blockers slow the heart rate which allows the ventricle a longer time to fill. They also reduce the heart’s oxygen demand, and help control certain rhythm disturbances. Adverse effects are usually related to excessive beta blockade and individual animals vary considerably in their response; thus, low doses are used initially and slowly increased to effect. Dosage and frequency of administration also depends on the drug used. Adverse effects can include excessively slow heart rate, worsening of heart failure, low blood pressure, depressed attitude, and possibly masking early signs of low blood sugar (especially in diabetics). Beta-blockers should not be given to a cat in congestive heart failure (CHF) unless the cat was already on one when asymptomatic.
