When do you consider intramuscular indomethacin for the assessment of trigeminal autonomic cephalalgias?

Indomethacin as a preventive treatment should only be considered for paroxysmal hemicrania and hemicrania continua. Both diagnoses are made based on the history. The diagnosis of paroxysmal hemicrania is based on the attack pattern: unilateral headaches lasting 10-30 minutes and occurring multiple times per 24 hours. A diagnosis of hemicrania continua is likely with a persistent, unilateral headache that responds well, although temporarily, to aspirin or an aspirin-like medication. Full resolution of the headache with a suitable dose of oral indomethacin (25-50 mg four times per day) confirms the diagnosis.

With both conditions, the benefit happens overnight, provided the indomethacin dose is adequate. Local autonomic symptoms are not requir...