Joseph is undergoing 24-hour ambulatory electrocardiography using a Holter monitor to determine the cause of his frequent episodes of syncope. To prevent electric interruption from the electrodes to the Holter monitor, Nurse Mike will instruct the client to avoid which of the following?
A. Drinking his favorite milkshake
B. Wearing loose-fitting clothing
C. Shaving with an electric razor
D. Standing close to a refrigerator
Correct Answer: A. Prevent metabolic breakdown of xanthine to uric acid
The massive cell destruction resulting from chemotherapy may place the client at risk for developing renal calculi; adding allopurinol decreases this risk by preventing the breakdown of xanthine to uric acid. These clients can have increased uric acid levels due to release of uric acid from the dying cancer cells.
Option B: Allopurinol and oxypurinol both inhibit xanthine oxidase, an enzyme in the purine catabolism pathway that converts hypoxanthine to xanthine to uric acid. Allopurinol undergoes metabolism in the liver, where it transforms into its pharmacologically active metabolite, oxypurinol.
Option C: Urate production is accelerated by purine-rich diets, endogenous purine production, and high cell breakdown, and it is responsible for a minority of cases of hyperuricemia. Foods rich in purine include all meats but specifically organ meats (kidneys, liver, “sweet bread”), game meats, and some seafood (anchovies, herring, scallops).
Option D: Allopurinol doesn’t act in the manner described in this option. To prevent tumor lysis syndrome, allopurinol shall be initiated 2 to 3 days before starting chemotherapy and continued until 3 to 7 days after chemotherapy.