Extrapyramidal Side Effects

Excerpt

Extrapyramidal side effects, also referred to as medication-induced movement disorders, are common adverse drug reactions caused by antipsychotic medications and other dopamine D2 receptor-blocking agents. These effects were first described in 1952 after chlorpromazine was recognized to produce side effects resembling Parkinson disease. Acute manifestations include dystonia, akathisia, tremor, and parkinsonism, whereas chronic manifestations include tardive dyskinesia, tardive akathisia, and tardive dystonia. Extrapyramidal symptoms may be hyperkinetic or hypokinetic (parkinsonian) movement disorders, with varying pathophysiology. These symptoms may arise due to medication use, but they can also occur without any medication exposure. Extrapyramidal symptoms are debilitating and interfere with social functioning and communication, motor tasks, and activities of daily living. As a result, individuals may experience an impaired quality of life, treatment nonadherence, increased morbidity, caregiver burden, and increased utilization of healthcare resources.

Movement disorder specialists contend that the term extrapyramidal is outdated and discourages accurate diagnosis. They argue that it is more helpful to describe the observed clinical motor phenomena, pursue the differential diagnosis, ascertain whether the symptoms are related to a primary motor disorder or are medication-induced, and manage accordingly.

The spectrum of acute symptoms in extrapyramidal symptoms is distressing and can include painful torticollis, oculogyric crisis, slurred speech, drooling, and trouble chewing or swallowing. If left untreated, acute symptoms may cause dehydration, infection, pulmonary embolism, rhabdomyolysis, respiratory stridor, and obstruction.