A nurse is caring for patients receiving clozapine, lithium, fluoxetine, and venlafaxine. Which patient should the nurse be most alert for problems associated with fluid and electrolyte imbalance?

Choice A reason: Clozapine, an antipsychotic, primarily causes agranulocytosis and metabolic issues, not fluid or electrolyte imbalances. Its effects on the central nervous system and bone marrow do not directly disrupt electrolyte homeostasis, making this choice incorrect for this concern. Choice B reason: Lithium, a mood stabilizer, affects renal function, impairing sodium and water reabsorption, leading to potential hyponatremia or dehydration. This requires close monitoring of electrolytes, as imbalances can cause toxicity, making this the correct choice for heightened alertness. Choice C reason: Fluoxetine, an SSRI, primarily affects serotonin levels, with minimal impact on fluid or electrolyte balance. Side effects like nausea do not significantly disrupt electrolytes, making this choice incorrect compared to lithium’s known renal effects. Choice D reason: Venlafaxine, an SNRI, influences serotonin and norepinephrine but does not significantly affect fluid or electrolyte balance. Its side effects, like hypertension, are unrelated to electrolyte homeostasis, making this choice incorrect for this specific concern.