Mental changes associated with tocainide, a new antiarrhythmic.
A case is reported in which tocainide, a relatively new cardiac antiarrhythmic for oral use, is believed to have caused a delirium. The patient had been admitted to a coronary intensive care unit for the treatment of ventricular arrhythmia and had developed confusion, impairment in concentration and severe anxiety. Her EEG was compatible with metabolic encephalopathy. The clinical picture varied with the use of tocainide so closely that it appeared to be the most likely cause of the delirium. Other factors were taken into consideration but did not seem to adequately disprove this impression. Tocainide has been known to cause minor, transient and treatable side effects in the form of gastrointestinal and central nervous symptoms--mainly nausea, tremor and dizziness. There have also been three case reports of paranoid psychoses. It is suggested that psychiatrists be aware of the above complications as they may have occasion to see patients taking tocainide, especially in consultation-liaison work. A table with the more common side effects and their frequencies is included.