Diclofenac Increases Beta-Endorphin Plasma Concentrations:

Plasma and ventricular cerebro-spinalfluid (CSF) Beta-endorphin concen­ trations were evaluated after chromatographic separation inpatients carrying a ventricular shunt before and after theadministration ofdiclofenac or placebo. In the same subjects the ventricularCSF concentrations ofthe serotonin and the catecholamine metabolites 5-hydroxyindole-acetic acid(5-HIAA), homovanillic acid(HVA) and MOPEG were also evaluated. Plasma, but not ventricular, Beta-endorphin concentrations increased significantly after diclofenac, while placebo was ineffective. No significant changes in ventricular 5-HIAA, HVA or MOPEG levels were observed. These data suggest a rolefor Beta-endorphin in the analgesic effectofdiclofenac.