Resistant Hypertension Responding to Change From Furosemide to Thiazide: Understanding Calcium Channel Blocker–Related Edema

Abstract

A 73-year-old man was referred to a hypertension clinic for hypertension resistant to three drugs, including a diuretic. Two years previously, hydrochlorothiazide (HCTZ) 25 mg increased to 50 mg was initiated and then followed by amlodipine 5 mg, then 10 mg daily. Due to the development of dependent peripheral edema, HCTZ was changed to furosemide 20 mg twice a day, then 40 mg twice a day. According to the patient, there was no appreciable change in the edema. Metoprolol 50 mg twice a day and losartan 50 mg daily were added prior to referral.At the time of the hypertension clinic evaluation, the patient's blood pressures (BPs) were 146 ⁄ 82 mm Hg and 144 ⁄ 84 mm Hg and physical examination was remarkable for 1+ bilateral ankle and bipedal edema. Serum creatinine was 1.2 mg ⁄ dL (normal 0.6-1.2 mg ⁄ dL) with an estimated glomerular filtration rate (GMR) of 56 cc ⁄ min (normal >90 cc ⁄ min). Furosemide was changed to chlorthalidone 25 mg daily with unchanged mild edema, and follow-up BPs were 134 ⁄ 80 mm Hg and 132 ⁄ 82 mm Hg. The patient was assured that his mild edema was not medically detrimental, and daytime compression stockings and leg elevation were advised as needed. DISCUSSION Hypertension Clinic Experience With Thiazide and FurosemideThe common experience of two university referral clinics for resistant hypertension has been that a chance to select a diuretic appropriate for renal function can occasionally lead to control.