PT  - JOURNAL ARTICLE
AU  - Eisenbrandt, L. L.
AU  - Adler, T. K.
AU  - Elliott, H. W.
AU  - Abdou, I. A.
TI  - THE ROLE OF THE GASTRO-INTESTINAL TRACT IN THE EXCRETION OF C<sup>14</sup>-LABELED METHADONE BY RATS
DP  - 1950 Feb 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 200--205
VI  - 98
IP  - 2
4099  - http://jpet.aspetjournals.org/content/98/2/200.short
4100  - http://jpet.aspetjournals.org/content/98/2/200.full
SO  - J Pharmacol Exp Ther1950 Feb 01; 98
AB  - Based on the determination of radioactivity after a subcutaneous injection of C14-labeled methadone*·HBr into rats, it was found that gastric excretion does not play a significant role in the elimination of the drug. The accumulation of radioactivity in the stomach is a result of regurgitation from the small intestine. The presence of radioactivity in the small intestine itself is a result of the inflow of radioactive bile. Radioactivity makes its appearance in the bile within ten minutes after a subcutaneous injection and becomes increasingly concentrated resulting in an increasing minute output as time progresses. As much as 17 per cent of an injected dose of 5 mgm./kgm. can be recovered from the bile during a period of three hours. An amount representing 1.5 per cent of a subcutaneous dose is readily reabsorbed from the small intestine within this period. In one pregnant rat, considerable amounts of radioactivity were found in the fetuses and placentae.