A nurse is providing teaching to a client who has a new prescription for allopurinol to treat gout. Which of the following instructions should the nurse include in the teaching?

Choice A rationale Allopurinol is a xanthine oxidase inhibitor used to reduce uric acid production. It does not have a direct effect on bowel motility, and constipation is not a common side effect. The instruction to increase dietary fiber is not a primary teaching point for this medication, as it does not address the drug's specific mechanism of action or side effect profile. Choice B rationale Allopurinol is a long-term preventative medication for gout and is taken as a single daily dose, not an hourly one. It works by inhibiting the enzyme xanthine oxidase, which reduces the production of uric acid, thereby preventing future gout attacks. Taking it hourly would lead to a dangerously high dose and potential toxicity. Choice C rationale While a rash is a known side effect of allopurinol, it should not be considered harmless. A severe and potentially life-threatening hypersensitivity reaction, such as Stevens-Johnson syndrome or toxic epidermal necrolysis, can occur. The client must be instructed to report any rash immediately and discontinue the medication. Choice D rationale Allopurinol can increase the risk of renal stone formation. Increasing fluid intake to 2 to 3 liters per day helps promote diuresis and flush uric acid crystals from the kidneys, reducing the risk of renal calculi. This action is crucial for preventing drug-induced kidney damage and is a key teaching point.