title: A radioimmunoassay for the antimalarial drug chloroquine.
abstract: We describe a 3H-based RIA for the antimalarial drug chloroquine (CLQ), the most commonly used antimalarial drug. In the assay a monoclonal antibody is used that is directed against 4-amino-7-chloroquinoline conjugated to keyhole limpet hemocyanin by the glutaraldehyde method. Besides CLQ, this antibody also recognizes with good affinity the 4-aminoquinoline homologs, hydroxychloroquine and amodiaquine. No extraction step or sample preparation is required, and the method can detect as little as 10 micrograms/L, the lower concentration in plasma of humans who are taking CLQ as a preventive measure. The between-assay CV is less than or equal to 10%, the within-assay CV less than or equal to 3%. Results correlate with those by liquid chromatography (r2 = 0.96). The speed and simplicity of the RIA method make it useful in evaluating the CLQ concentrations in acutely toxic patients.
mesh_terms: D000911:Antibodies, Monoclonal; D002738:Chloroquine / Q000097:blood*; D002851:Chromatography, High Pressure Liquid; D003429:Cross Reactions; D006801:Humans; D011863:Radioimmunoassay / Q000379:methods
chemical_list: D000911:Antibodies, Monoclonal; D002738:Chloroquine