Psychic side effects of a chlorzoxazone and acetaminophen mixture; a case report

A mixture of chlorzoxazone, 250 mg, and acetaminophen, 300 mg (Parafon Forte) was administered in tablet form to a 21-year-old man. The patient had received no previous medication and had no history of food or drug allergies. Following ingestion of the tablets, the patient experienced headaches, spatial disorientation, a dream-like state, nausea, vomiting, peripheral paresthesias, and amnesia. Several of these symptoms have not been previously reported as side effects of this medication. The side effect symptoms appeared to be directly related to the ingestion of the mixture; all symptoms cleared 24 hours after the medication was discontinued.