Immunoassays for the detection of nicergoline and its metabolites in humanplasma

In order to determine nicergoline pharmacokinetics after oral administratio n to humans, we have developed two radioimmunoassays, one directed against nicergoline and the other directed against known nicergoline metabolites. T he assays were validated according to the recommendations of international regulatory agencies and their limits of quantification were 40 and 10 pg/ml , respectively. In order to further validate the methods, a chromatographic separation of immunoreactive entities was performed with samples from heal thy volunteers who were given 15 mg of Sermion(R) (nicergoline orally admin istered). Chromatographic determination of assay specificity showed that th e metabolite radioimmunoassay recognised known nicergoline metabolites bur also a new metabolite. Using the antibodies directed against nicergoline, w e were unable to detect nicergoline in the human plasma, This suggests that nicergoline is absent in the circulation because of complete metabolism th rough its first-pass effect. (C) 2001 Elsevier Science B.V. All rights rese rved.