Return to Table of Contents

Renal Case #1

authored by Margaret McDougal, M.D., Ph.D. (c) 1997
used with permission

edited by Michael Gordon, Ph.D.

A 55 year old white male with a history of hypertension for 15 years comes for a  second opinion. He indicates that his blood pressure always runs about 100 mm Hg diastolic. He also tells you he has a history of gout in his left knee. He denies any shortness of breath, chest pain, or edema, but does admit to nocturia about twice nightly. He denied taking medication presently.


Physical Examination:

  • bp 180/100 with Pulse 60 regular, supine and standing, both arms.

  • Fundi: AV nicking and arteriolar narrowing bilaterally

  • ENT: marked parotid gland enlargement

  • Neck: left carotid bruit

  • Chest: increased AP diameter, decreased breath sounds throughout

  • CVS: without gallop or rub. Gr II/IV SEM (systolic ejection murmur) at LLSB (lower left sternal border), increased A2

  • ABD: moderately obese, Bowel sounds normal. No masses, tenderness, or bruits. Liver span 12 cm. Femoral pulses decreased with left femoral bruit.

  • EXT: without edema or cyanosis. Marked palmar erythema and clubbing. Markedly diminished lower extremity pulses.

Initial Laboratory Values:

  • BUN 45, Creatinine 4, Na 142, K 4.6, Cl 99, CO2 244, Glucose 210. Cholesterol 280, Uric Acid 10.3, Triglycerides 310, Ca 7.8, PO4 6.5.

He was started on 50 mg hydrochlorothiazide (HCTZ, Esidrix, HydroDIURIL)/75 mg triamterene (Dyrenium). He returned two weeks later. BP now 168/100. BUN 60, Creatinine 6.2, K 6.8.

What happened to the patient when he was given hydrochlorothiazide (HCTZ, Esidrix, HydroDIURIL) for his blood pressure? How do you explain the changes in his renal function over the two weeks of treatment?