A 43-year-old, insulin-dependent diabetic patient is diagnosed with hypertension and begins therapy with an antihypertensive agent. Three days later, he measures his blood glucose at home and finds that it is 53 mg/dL. He recalibrates his glucose testing apparatus and repeats the test, only to find that the first reading was accurate. He is concerned that his hypoglycemia did not produce the normal premonitory signs and symptoms. Which of the following medications was most likely prescribed to treat his hypertension?
The correct answer is E.
Beta-adrenergic blockade may blunt or prevent the premonitory signs and symptoms (e.g., tachycardia, blood pressure changes) of acute episodes of hypoglycemia. Non-selective beta-blockers, such as propranolol, may even potentiate insulin-induced hypoglycemia. Even though this effect is less likely with cardioselective agents, the use of either cardioselective or non-selective beta-blockers in diabetics is not recommended due to their “masking” effect of the normal warning signs and symptoms of hypoglycemia. None of the drugs listed in the other choices will blunt the premonitory signs and symptoms of hypoglycemia.
Captopril (choice A) is an angiotensin-converting enzyme (ACE) inhibitor that can be safely used for the treatment of hypertension in diabetic patients.
Diltiazem (choice B) is a calcium channel blocker that is also considered to be safe and effective for the treatment of hypertension in diabetic patients.
Both methyldopa (choice C), a centrally acting alpha-adrenergic agonist , and prazosin (choice D), an alpha1-adrenergic antagonist, can be safely used to treat hypertension in diabetic patients. However, due to the side effect profile of these medications, they are generally used only in diabetic patients who are unresponsive to ACE inhibitors and calcium channel blockers.