Comprehensive Nursing Pharmacology Q 38
A nurse is planning dietary counseling for the client taking triamterene (Dyrenium). The nurse plans to include which of the following in a list of foods that are acceptable?
A. Baked potato
B. Bananas
C. Oranges
D. Pears canned in water
Correct Answer: D. Pears canned in water
Triamterene is a potassium-sparing diuretic, and clients taking this medication should be cautioned against eating foods that are high in potassium, including many vegetables, fruits, and fresh meats. Because potassium is very water-soluble, foods that are prepared in water are often lower in potassium.
Option A: Among the potassium-sparing diuretics, triamterene was the second drug of this class to be FDA approved for use in the US following spironolactone. However, despite these two drugs being within the same class and achieving the same desired result, they have two distinct mechanisms of action. While spironolactone is an aldosterone receptor antagonist operating at the late distal tubule and collecting tubules of the nephron on the apical aspect of these sites, triamterene acts at the same region of the nephrons but specifically at the epithelial sodium channels (ENaC) which are on the luminal side. These channels are transmembrane channels that operate to increase sodium uptake in exchange for secreting potassium.
Option B: Potassium-sparing diuretics overdose is relatively rare, and there are no reports of deaths. With mild to moderate toxicity, there can be the development of nausea, vomiting, diarrhea, mild dehydration, and hyperkalemia. If there is severe toxicity, there can be the development of severe dehydration coupled with hyperkalemia, which may lead to dysrhythmias, tachycardia, hypotension, hyperactive deep tendon reflexes, and possibly changes in mental status.
Option C: With the use of triamterene, it is essential to monitor specific labs and blood pressure of patients taking this drug in either its sole or combination form with HCTZ. BUN/creatinine, blood pressure, urine output, serum uric acid, CBC, and electrolytes in particular serum potassium should be monitored at a baseline when first placed on the drug. Once findings indicate the establishment of a stable tolerance of the drug, it can be periodically monitored, specifically when dose changes are made and during illnesses.