
These symptoms often happen during the first few days of taking haloperidol. These include involuntary movements, such as hand tremor and shaking, stiff and slow movements, agitation or restlessness, and muscle spasms. Movement symptoms: Haloperidol may trigger extrapyramidal symptoms.This syndrome can damage your muscles and kidneys. If you experience these symptoms, stop taking haloperidol right away and get medical help. Symptoms may include fever, rigid or stiff muscles, changed mood, irregular pulse or blood pressure, fast or irregular heartbeat, and unexplainable sweating.

This occurs due to haloperidol’s interference with dopamine.

Neuroleptic malignant syndrome: Haloperidol may cause a severe reaction called neuroleptic malignant syndrome.
