After intravenous administration of DTIC-Dome, the volume of distribution exceeds total body water content suggesting localization in some body tissue, probably the liver. Its disappearance from the plasma is biphasic with initial half-life of 19 minutes and a terminal half-life of 5 hours. ¹ In a patient with renal and hepatic dysfunctions, the half-lives were lengthened to 55 minutes and 7.2 hours. ¹ The average cumulative excretion of unchanged DTIC in the urine is 40% of the injected dose in 6 hours. ¹ DTIC is subject to renal tubular secretion rather than glomerular filtration. At therapeutic concentrations DTIC is not appreciably bound to human plasma protein.

In man, DTIC is extensively degraded. Besides unchanged DTIC, 5-aminoimidazole -4 carboxamide (AIC) is a major metabolite of DTIC excreted in the urine. AIC is not derived endogenously but from the injected DTIC, because the administration of radioactive DTIC labeled with ¹⁴ C in the imidazole portion of the molecule (DTIC-2- ¹⁴ C) gives rise to AIC-2- ¹⁴ C. ¹

Although the exact mechanism of action of DTIC-Dome is not known, three hypotheses have been offered:

1. inhibition of DNA synthesis by acting as a purine analog
2. action as an alkylating agent
3. interaction with SH groups

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