A Case of Disulfiram-Methylphenidate Interaction: Implications for Treatment

A 33-year-old man was hospitalized for a convulsive episode in an intensive care unit. He was diagnosed with alcohol abuse and was noted to have a past history of alcohol and other substance abuse since the age of 15. After 1 month, he was transferred to another clinical unit where he received a diagnosis of attention deficit disorder. During this stay, he was prescribed disulfiram (400 mg/day), without any noticeable adverse effect. The patient was later discharged, and after returning home he began treatment for the first time with OROS-methylphenidate (36 mg daily). After receiving his first dose of methylphenidate, he rapidly experienced a psychotic-like episode that lasted throughout the morning until the end of the afternoon. He denied any alcohol intake and described the experience as similar to acute cocaine intoxication with visual hallucinations. He discontinued methylphenidate, continued to receive disulfiram and vitamins, and recovered fully.

Two months later, in an outpatient follow-up visit, the patient’s diagnosis of attention deficit disorder was confirmed as the predominantly inattentive subtype according to DSM-IV criteria. His score on the screening portion of the Adult ADHD Symptoms Rating Scale (1) was 5 (out of a maximum of 6). His score on the 25-item Wender Utah Rating Scale was 59, strongly in favor of significant inattentive/hyperactive symptoms in childhood (2) . There was no clinical evidence of psychosis, anxiety, or depression. Three months following this assessment, the patient discontinued receiving disulfiram. He was then prescribed OROS-methylphenidate (36 mg/day). No adverse effect was reported in the weeks thereafter, and the dosage was increased to 54 mg/day over the following 3 months, without adverse effect or recurrence of the psychotic experience.