@article {Spector73, author = {S Spector}, title = {Disposition of drugs in man by radioimmunoassay.}, volume = {34}, number = {1}, pages = {73--76}, year = {1982}, publisher = {American Society for Pharmacology and Experimental Therapeutics}, 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.}, issn = {0031-6997}, URL = {https://pharmrev.aspetjournals.org/content/34/1/73}, eprint = {https://pharmrev.aspetjournals.org/content/34/1/73.full.pdf}, journal = {Pharmacological Reviews} }