[Demonstration of drug-specific IgE and IgG antibodies using RIA: clinical importance as shown with nomifensin (Alival)].

Serum samples from 41 patients who developed adverse reactions during therapy with nomifensine were screened by RAST-based immunoassay for specific IgE and IgG antibodies against nomifensine and three of its metabolites. The results were compared with those of 10 patients without side effects and with 8 non-treated controls. Nomifensine-specific IgE antibodies were found in none of the subjects. However, all patients treated with nomifensine (with and without side effects) had specific IgG antibodies. The antibody cross-reacted in all cases with the metabolites. The titers did not discriminate clearly between the different side reactions and only partially between the presence or absence of a side reaction. The finding of specific anti-drug IgG antibodies warrants more detailed investigation of immunological mechanisms, to determine the clinical relevance of these antibodies and identify patients at risk for serious side effects.