A nurse is assessing a client who is receiving treatment with multiple antipsychotic medications and who suddenly became ill. Findings include blood pressure changes, hyperpyrexia, and diaphoresis. The nurse should recognize that which of the following adverse effects may be occurring?

Choice A reason: Tardive dyskinesia is a late-onset adverse effect of antipsychotic medications characterized by involuntary, repetitive movements such as lip smacking, tongue protrusion, or grimacing. It develops gradually after prolonged use of antipsychotics and does not present with acute systemic symptoms like hyperpyrexia or blood pressure instability. Therefore, this does not match the acute presentation described. Choice B reason: Neuroleptic malignant syndrome is a rare but life-threatening reaction to antipsychotic medications. It presents with hyperpyrexia (extremely high fever), autonomic instability such as blood pressure fluctuations, diaphoresis, muscle rigidity, and altered mental status. These symptoms align exactly with the findings in the question stem, making this the correct answer. Immediate recognition and intervention are critical to prevent complications such as rhabdomyolysis and renal failure. Choice C reason: Pseudoparkinsonism is an extrapyramidal side effect that mimics Parkinson’s disease, with symptoms such as tremors, shuffling gait, bradykinesia, and rigidity. It does not involve systemic signs like fever or autonomic instability. Thus, it does not explain the acute illness described. Choice D reason: Acute dystonia is an extrapyramidal reaction characterized by sudden, severe muscle spasms, often of the neck, face, or back. While distressing, it does not cause systemic symptoms such as hyperpyrexia or diaphoresis. Therefore, this is not the correct adverse effect in this scenario.