Adenosine causes short-lasting vasodilation and headache but not migraine attacks in migraine patients: a randomized clinical trial.

Migraine is a common disabling disease with a complex pathophysiology. Headache is a frequent side effect after intravenous adenosine administration, although adenosine receptor antagonist, caffeine, relieves migraine headache. These observations suggest a possible involvement of adenosine signaling in headache and migraine pathophysiology. In a randomized, double-blinded, placebo-controlled, crossover study, 18 participants diagnosed with migraine without aura received 120 µg/kg per minute adenosine or placebo over 20 minutes. Headache intensity, migraine-associated symptoms, vital signs, the diameter of the superficial temporal artery (STA), blood flow velocity in the middle cerebral artery (V MCA ), and facial skin blood flow were measured at baseline and every 10 minutes until 2 hours after infusion start. The primary end point was the difference in the incidence of migraine attacks after adenosine infusion compared with placebo. Eighteen participants completed the study. We found no difference in the incidence of migraine after adenosine infusion (7 of 18, 39%) compared with placebo (3 of 18, 17%) ( P = 0.29). Fourteen participants reported headache after adenosine infusion (14 of 18, 78%) compared with placebo (6 of 18, 33%) ( P < 0.01). Adenosine increased heart rate ( P < 0.001), facial skin blood flow ( P < 0.05), and STA diameter (AUC T0-20min , P = 0.01) and decreased V MCA (AUC T0-20min , P < 0.001) compared with placebo. Adenosine induced headache accompanied by a short-lasting (<30 minutes) dilation of intracerebral and extracerebral arteries. The nonsignificant migraine induction might be because of the presence of several adenosine receptors with counteracting signaling, highlighting the need of more selective modulators to dissect the implication of adenosine in migraine.