Question

How do beta blockers affect the sympathetic nervous system?How might a non selective beta blocker affect client with asthma?what should you be aware if client is a diabetic and taking beta blocker?

Answer 1

Answer : Beta blockers are a class of medications that are predominantly used to manage abnormal heart rhythms, and to protect the heart from a myocardial infarction. They are also widely used to treat high blood pressure. Beta blockers are competitive antagonist that block the receptor sites for the endogenous catechloamines epinephrine (adrenaline) and norepinephrine (nordrenaline) on adrenergic beta receptors ,of the sympathetic nervous system ,which mediates the fight -or - flight response. Adrenaline and nordrenaline prepare the muscles in the body for exertion .The sympathetic nervous system is part of the autonomic nervous system . Non -selective beta- blockers such as propanolol, atenolol and metoprolol are contraindicated in patients with asthma or COPD because these drugs could precipitate severe bronchospasm in patients with asthma ,especially at high doses. It also increase airway resistance . Beta blockers slow heartbeat ,heart, s response to low blood sugar may not be as obvious. In insulin -dependant diabetes ,beta blockers can prolong, enhance or alter the symptoms of hypoglycemia ,while hyperglycemia appears to be the major risk in non-insulin dependant diabetics.Hypoglycemia may occur by impairing the release of insulin from the pancreatic β -cell .