A nurse is caring for a client who has a prescription for acyclovir IV three times daily.
Which of the following actions should the nurse take?

Choice A rationale

Allopurinol is a xanthine oxidase inhibitor. This enzyme is crucial in the purine catabolism pathway, converting xanthine and hypoxanthine into uric acid. By inhibiting xanthine oxidase, allopurinol effectively decreases the de novo synthesis of uric acid, thereby lowering serum uric acid levels. This reduction prevents the formation of uric acid crystals in joints and tissues, which are responsible for the painful manifestations of gout.

Choice B rationale

Tophus formation is a direct consequence of chronic hyperuricemia, where uric acid crystals accumulate in soft tissues, leading to palpable nodules. Allopurinol's primary mechanism of action is to reduce uric acid levels. By achieving this, it prevents further crystal deposition and can even lead to the regression of existing tophi over time. Therefore, it does not increase tophus formation.

Choice C rationale

Allopurinol's mechanism of action is specifically related to uric acid metabolism. It does not directly influence calcium homeostasis in the body. Calcium levels are primarily regulated by parathyroid hormone, calcitonin, and vitamin D, which are distinct physiological pathways unrelated to xanthine oxidase inhibition. Therefore, it does not lower calcium levels.

Choice D rationale

While allopurinol ultimately helps relieve joint inflammation in gout, it does so indirectly. Its primary action is to reduce uric acid production, which then prevents the formation of inflammatory uric acid crystals. The direct reduction of inflammation is typically achieved by anti-inflammatory drugs like NSAIDs or colchicine, which act on inflammatory mediators or pathways, not directly by allopurinol.

Choice A rationale

Nystagmus, an involuntary rhythmic eye movement, is not a recognized or common adverse effect of oral albuterol. Albuterol is a beta-2 adrenergic agonist primarily acting on bronchial smooth muscle to cause bronchodilation. Its side effects are typically related to sympathetic nervous system stimulation, not oculomotor dysfunction.

Choice B rationale

Tachycardia is a common adverse effect of oral albuterol due to its systemic absorption and stimulation of beta-1 adrenergic receptors in the heart, in addition to its primary beta-2 effects on the lungs. This leads to an increased heart rate (normal range 60-100 bpm) and can cause palpitations, especially in sensitive individuals or with higher doses.

Choice C rationale

Drowsiness is not a typical adverse effect of oral albuterol. In fact, due to its stimulant properties, albuterol is more likely to cause central nervous system excitation, leading to insomnia, nervousness, or tremors rather than sedation. Its action is to activate adrenergic pathways, which generally promote alertness.

Choice D rationale

Oral fungal infections, such as oral candidiasis (thrush), are commonly associated with inhaled corticosteroids, not oral albuterol. Inhaled corticosteroids suppress the local immune response in the oral cavity, allowing opportunistic fungal growth. Oral albuterol does not have immunosuppressive effects on the oral mucosa.