Hemicrania continua: Indomethacin induced myoclonus.

Myoclonus has been described rarely as an adverse effect with some non-steroidal anti-inflammatory drugs, but never with indomethacin. Indomethacin is a common nonsteroidal anti-inflammatory drug used for various primary headache disorders, including hemicrania continua. We present a rare case of a 45-year-old male with hemicrania continua who developed myoclonus from indomethacin. These movements resolved completely following discontinuation of indomethacin. The disturbance on the serotonergic and GABAergic systems may be associated with indomethacin induced myoclonus. Clinicians and patients should be mindful with this potential side effect with indomethacin.