A nurse is administering haloperidol to a client who has schizophrenia. For which of the following adverse effects should the nurse monitor?

Choice A rationale Gingival hyperplasia is an overgrowth of gum tissue, often associated with certain medications like phenytoin or cyclosporine. It is caused by an increase in the number of fibroblasts and collagen deposition in the gingiva. Haloperidol, an antipsychotic, primarily affects dopamine receptors in the brain and does not cause gingival hyperplasia. Choice B rationale Haloperidol is a first-generation antipsychotic that blocks D2 dopamine receptors in the brain. This blockade, particularly in the nigrostriatal pathway, can lead to extrapyramidal symptoms (EPS) such as acute dystonia, parkinsonism (including muscle rigidity, bradykinesia, and tremor), and akathisia. Muscle rigidity is a common manifestation of drug-induced parkinsonism. Choice C rationale Polyuria is the excessive production of urine, often a symptom of diabetes mellitus or insipidus. It results from impaired water reabsorption in the kidneys. While some medications can affect fluid balance, haloperidol's primary pharmacological action on dopamine receptors does not directly induce polyuria as a typical adverse effect. Choice D rationale Bruising, or ecchymosis, results from bleeding under the skin, often due to trauma or coagulation disorders. It is caused by extravasation of blood from capillaries into surrounding tissues. Haloperidol does not affect coagulation factors or platelet function and is not associated with increased bruising as a direct adverse effect.