Dopamine D2 receptor blockade and antimigraine action of flunarizine.
We studied in vivo the influence of flunarizine on dopamine D2 receptors and investigated whether dopamine D2 receptor blockade is involved in its antimigraine action. Eleven migraine patients, treated with flunarizine, 10 mg per day, underwent single photon emission computer tomography (SPECT) using [123I] labeled iodobenzamide, a ligand with high affinity and high specificity for D2 receptors. There was a reduction of the dopamine D2 receptor binding potential in all patients compared to age-matched controls. The efficacy of flunarizine in migraine prophylaxis failed to correlate with the degree of the dopamine D2 receptor blockade. The antimigraine action of flunarizine may not involve antidopaminergic mechanisms.
Department of Neurology, University of Vienna, Austria.
C
C
Wöber
T
T
Brücke
C
C
Wöber-Bingöl
S
S
Asenbaum
P
P
Wessely
I
I
Podreka
D000328:Adult; D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging / Q000187:drug effects; D065127:Dopamine D2 Receptor Antagonists; D005260:Female; D005444:Flunarizine / Q000009:adverse effects / Q000627:therapeutic use*; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D008881:Migraine Disorders / Q000188:drug therapy* / Q000503:physiopathology; D017448:Receptors, Dopamine D2 / Q000502:physiology; D015899:Tomography, Emission-Computed, Single-Photon
D065127:Dopamine D2 Receptor Antagonists; D007457:Iodine Radioisotopes; D017448:Receptors, Dopamine D2; D005444:Flunarizine