Which symptom reported by a client alerts the practical nurse (PN) to withhold a scheduled dose of hydrochlorothiazide and notify the healthcare provider?

Choice A reason: Serum lithium levels indicate compliance but do not directly explain the need for frequent monitoring. Lithium’s therapeutic effect stabilizes mood, but monitoring is primarily due to its narrow therapeutic index, where small changes in blood levels can cause toxicity, not just behavioral changes or compliance.

Choice B reason: Sodium levels affect lithium excretion, as both compete for renal reabsorption. Low sodium increases lithium retention, risking toxicity, while high sodium increases excretion, reducing efficacy. Lithium’s narrow therapeutic range (0.6–1.2 mEq/L) necessitates frequent monitoring to prevent toxic levels, which can cause neurological or cardiac issues.

Choice C reason: Myelosuppression and agranulocytosis are not common lithium side effects. Lithium may cause mild leukocytosis, not suppression. Toxicity risks, like neurological or renal effects, drive monitoring needs, not hematologic issues. This choice is incorrect, as it misrepresents lithium’s side effect profile.

Choice D reason: Tyramine, relevant to monoamine oxidase inhibitors, does not influence lithium metabolism. Lithium’s pharmacokinetics are affected by sodium and renal function, not dietary tyramine. This choice is incorrect, as it falsely links a dietary factor to lithium’s monitoring requirements.

Choice A reason: Digoxin toxicity can cause visual disturbances, like seeing yellow halos, due to its effect on retinal cone cells. The client’s comment about a yellow uniform suggests this side effect. Evaluating for toxicity, including checking serum digoxin levels, is critical, as toxicity can lead to life-threatening arrhythmias.

Choice B reason: Withholding furosemide and forcing fluids is inappropriate, as the client’s visual symptom points to digoxin toxicity, not furosemide-related issues. Furosemide causes diuresis, but no evidence suggests dehydration here. This choice does not address the likely digoxin-induced visual disturbance.

Choice C reason: Assuming the client is joking ignores a potential digoxin toxicity symptom. Visual changes, like yellow-tinted vision, are serious and require investigation, not dismissal. Administering medications without evaluation risks exacerbating toxicity, making this choice unsafe and incorrect.

Choice D reason: Additional potassium-rich foods are unnecessary, as the client is already receiving potassium chloride. The visual symptom suggests digoxin toxicity, not hypokalemia. Potassium levels may influence digoxin toxicity, but the priority is evaluating digoxin’s effects, not dietary intervention.