Extrapyramidal side effects of antiemetics presenting as psychiatric illness.

Although extrapyramidal side effects of two commonly used antiemetics, metoclopramide and prochlorperazine, are well known, it may be difficult for even the experienced practitioner to distinguish some of these extrapyramidal reactions from such psychiatric symptoms as anxiety, depression, or catatonia. Certain patient groups have increased susceptibility to these extrapyramidal reactions, including patients under 30, those with AIDS, those with renal disease, oncology patients, and possibly women. Physicians should maintain a high index of suspicion for depression, anxiety, or catatonia if their patients are taking antiemetics. These symptoms may be extrapyramidal side effects of the antiemetic rather than indications of a primary mental disorder.