Distribution of [14C] bemegride in tissues after intravenous injection.

The distribution and excretion of bemegride labelled at the alpha carbon atoms with (14)C were studied in mice, rats, and guinea-pigs. These studies were supplemented by others made by colorimetric and absorptiometric methods on unlabelled bemegride in the body fluids of rabbits and dogs. Bemegride passed rapidly from plasma to all tissues, including brain, muscle, and fat. In addition it passed readily into the cerebrospinal fluid and the aqueous humour and to the foetus. It persisted in the tissues for longer than 24 hr., to some extent preferentially in the central nervous system. Approximately two-thirds of the dose was excreted in the bile, faeces, and urine within 24 hr. The glutarimide ring of bemegride was not completely degraded biologically.