Question

A nurse is counseling a patient who will begin taking propranolol [Inderal], 40 mg, PO, three times daily. The patient has angina pectoris and Type 2 diabetes mellitus. He will be taking insulin and oral hypoglycemic medications along with the propranolol..

The nurse cautions the patient to check his blood sugars more frequently because:

Question options:

a)	the beta blocker inhibits p450 enymes, resulting in increased blood levels of oral hypoglycemic drugs

b)	beta blockers are p450-inducing drugs, and the propranol will decrease levels of the oral hypoglycemic medications increasing the patient's risk for hyperglycemia

c)	the beta blocker can blunt tachycardia and anxiety, which are signs that alert the patient to episodes of hypoglycemia

d)	the beta blocker antagonizes insulin receptors making blood sugar control more difficult.

Answer 1

patient was started on Propranolol, non selective beta blocker. It acting on b1 and b2 receptors. It should use in caution in diabetics on oral hypoglycemic agents. These patients may going for hypoglycemic as a result of drugs. Symptoms of hypoglycemia include tachycardia and tremor, which is due to action of sympathetic system. Beta blocker will block these effects and mask the symptoms of hypoglycemia. Prolong recovery from hypoglycemia. So option C is true.

Propranolol is neither an inducer or inhibitor of CYP 450.so options A, B are false. It has no effect on insulin receptors and option D is false.