RESUMEN
This study was undertaken to evaluate the effect of treatment with prednisone or verapamil on plasma met-enkephalin (ME), neutrophil met-enkephalin containing peptides (NMECP) and free and conjugated plasma catecholamines (CA) in cluster headache (CH) patients. After obtaining a basal sample, patients were randomly selected to be treated with either verapamil (n = 5) or prednisone (n = 5). A second blood sample was obtained 10 days after starting treatment. At this time all patients were free of symptoms. ME (0.49 +/- 0.10 pmol/mL) and NMECP (35.1 +/- 2.4 pmol/mg protein) levels after prednisone treatment were significantly higher (P < 0.05) than in basal conditions (0.29 +/- 0.08 pmol/mL and 27.14 +/- 2.4 pmol/mg protein), while no differences were found in catecholamine levels. No differences in ME, NMECP or CA were found during verapamil treatment. Our results suggest that in CH the two drugs act through different mechanisms. The relief of the bout obtained with prednisone may be related to the opioid system stimulation observed in these patients.