Abstract
1. The disposition of 14C-guanazole has been examined in the mouse, rat and dog.
2. Guanazole is rapidly excreted in the urine of mice and rats after parenteral administration with 90% of the dose found in mouse urine 2 to 3 h following parenteral administration. Excretion of guanazole by the anaesthetized dog is slower than that by the mouse or rat with 80% appearing in the urine within 6h.
3. No evidence was found for the metabolism of guanazole and apparently this antitumour agent is excreted unchanged in these three species.
4. The rapid excretion of guanazole offers an explanation for its greater antitumour activity when given frequently rather than on a once a day schedule.