Paranoid psychosis after a single parenteral dose of indomethacin administered for headache diagnosis: A case and review of the literature

Indomethacin is a non-steroidal anti-inflammatory used to diagnose and treat hemicrania continua and paroxysmal hemicrania. Treatment can be complicated by gastrointestinal adverse effects; less commonly reported are idiosyncratic neuropsychiatric adverse effects with indomethacin. A 50-year-old male with lateralized brief attacks of headache associated with cranial autonomic symptoms was administered a single 200 mg dose of intramuscular indomethacin. Within an hour, he developed acute psychosis, with paranoid delusions and verbal and physical aggression lasting 5 h, followed by recovery to baseline. We used search terms “indomethacin psychosis,” “indomethacin psychiatric,” “indomethacin side effects,” “non-steroidal anti-inflammatory psychosis,” and “non-steroidal anti-inflammatory psychiatric” within PubMed to identify previous reports and literature in this area. Neuropsychiatric adverse effects of indomethacin have been reported since 1965 in a dose-dependent manner, usually with oral courses. They may be more common in the elderly, postpartum women and postoperative patients. Neuropsychiatric adverse effects should be considered in headache medicine, particularly in at-risk groups when indomethacin is administered. Patients, particularly those at highest risk, should be counseled about the risk of neuropsychiatric side effects on indomethacin which may be dose-dependent and are generally reversible on stopping the drug.