title: Disposition of drugs in man by radioimmunoassay.
abstract: The disposition of morphine and clonidine was investigated by means of radioimmunoassay. After the administration of a single i.v. dose of morphine (10 mg/70 kg) to 10 men who had not received other drugs for two weeks preceding the study, a multiphasic decline in serum concentrations of morphine occurred. Detectable blood concentrations of morphine, or a metabolite, or of both, persisted for up to 96 hours after a single i.v. dose. The radioimmunoassay for clonidine is capable of detecting as little as 10 pg of clonidine. The antibody fails to bind 2,6-dichlorophenylguanidine, a known metabolite of clonidine, while the other metabolite, 4-hydroxyclonidine, was as potent as clonidine in displacing labeled clonidine from the antibody. The disposition of clonidine ion plasma and tissues could be monitored by radioimmunoassay.
mesh_terms: D001665:Binding Sites; D003000:Clonidine / Q000097:blood / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D008297:Male; D009020:Morphine / Q000097:blood; D004364:Pharmaceutical Preparations / Q000097:blood*; D011863:Radioimmunoassay
chemical_list: D004364:Pharmaceutical Preparations; D009020:Morphine; D003000:Clonidine