A 55-year-old man comes to the office for hypertension follow-up. He was diagnosed with hypertension 5 years ago and since then has been treated with benazepril and amlodipine. His blood pressure has been consistently high over the past 6 months despite dietary modifications to decrease salt intake. Medical history is significant for hypercholesterolemia. The patient does not smoke or consume alcohol. Blood pressure is 152/94 mm Hg and pulse is 80/min. BMI is 30 kg/m² with increased waist-to-hip ratio. Adding chlorthalidone to the patient's current therapy is considered to improve control of the hypertension. Which of the following metabolic effects may be expected as a result of this therapy?

Question

Quizplus · Accepted Answer

11ec25c8_d2e8_29d7_bc81_63e4efd3ff00_MD0003_00 Thiazide diuretics (eg, chlorthalidone, hydrochlorothiazide) are widely used antihypertensive medications that are effective as monotherapy or in combination with other agents. At lower doses, chlorthalidone is more effective than other thiazides and is associated with a lower rate of heart failure compared with other antihypertensive agents (possibly due to its ability to achieve lower blood pressure as a single agent). However, thiazides can raise the patient's blood sugar level due to impairment of both insulin release from the pancreas and glucose utilization in peripheral tissues. Thiazide-induced glucose intolerance is seen more commonly in patients with diabetes mellitus and metabolic syndrome (ie, hypertension, dyslipidemia, and abdominal obesity). The metabolic adverse effects of thiazide diuretics are dose-dependent, therefore significant blood pressure reduction can be achieved with minimal side effects when low doses are used. (Choices A and B) Thiazide diuretics can unfavorably affect lipid metabolism by increasing (not decreasing) LDL cholesterol and plasma triglyceride levels. (Choices D, E, and F) Thiazides increase renal excretion of sodium, potassium, and magnesium and decrease excretion of calcium. This can potentially lead to hyponatremia, hypokalemia, hypomagnesemia, and hypercalcemia. Thiazides also reduce renal uric acid excretion, and the resulting hyperuricemia predisposes to gout. Educational objective: Adverse metabolic effects of thiazide diuretics include hyperglycemia, increased LDL cholesterol and plasma triglycerides, and hyperuricemia. Electrolyte abnormalities that can be induced by thiazide diuretics include hyponatremia, hypokalemia, hypomagnesemia, and hypercalcemia. References: Thiazide and loop diuretics. (http://www.ncbi.nlm.nih.gov/pubmed/21896142) Best thiazide diuretic for hypertension. (http://www.ncbi.nlm.nih.gov/pubmed/22859628)

A 55-Year-Old Man Comes to the Office for Hypertension Follow-Up