What side effect is a client likely experiencing if they report feeling jittery after high doses of haloperidol?

If a client reports feeling jittery after receiving high doses of haloperidol, it is indicative of akathisia. Akathisia is a common side effect of antipsychotic medications, especially first-generation antipsychotics like haloperidol. It is characterized by an intense restlessness and an uncontrollable need to be in constant motion. Clients may describe this sensation as feeling jittery or unable to sit still, often leading to significant discomfort.

In the context of this medication, akathisia arises from the drug’s dopamine-blocking properties, which can disrupt normal motor activity. This effect is particularly noticeable at higher doses, where the likelihood of developing such a side effect increases.

Parkinsonism could cause muscle rigidity and bradykinesia but is less associated with the feeling of restlessness described. Neuroleptic malignant syndrome presents with severe muscle rigidity and autonomic disturbances, which are more acute and life-threatening, rather than the jitteriness experienced in akathisia. Tardive dyskinesia manifests with repetitive, involuntary movements, usually after long-term exposure to antipsychotics, and does not typically present with jitteriness either.

Understanding these distinctions helps clarify why akathisia is the most appropriate answer.