Baer J E, Jacob T A, Wolf F J
J Toxicol Environ Health. 1977 Mar;2(4):895-903. doi: 10.1080/15287397709529487.
The anthelmintic cambendazole is rapidly metabolized to at least 13 urinary metabolites. Radioactivity was found in liver for weeks after a single dose in cattle, but even at 3 days' withdrawal, cambendazole and metabolites previously identified in urine accounted for only a small fraction of liver radioactivity. The radioactivity was ubiquitously distributed in protein and nucleic acid fractions, and [14C] glutamic acid was identified, indicating incorporation of 14C into the endogenous pool. Part of the residual liver radioactivity at 7 days was convertible chemically to 5-nitrobenzimidazole, indicating a drug-related macromolecular residue. However, data from rats fed radiolabeled steer liver indicate that the residue is minimally bioavailable and therefore of substantially less toxicological concern than cambendazole itself.
驱虫药坎苯达唑迅速代谢为至少13种尿液代谢物。在牛单次给药后数周，肝脏中仍可检测到放射性，但即使在停药3天后，尿液中先前鉴定出的坎苯达唑及其代谢物仅占肝脏放射性的一小部分。放射性广泛分布于蛋白质和核酸部分，并且鉴定出了[14C]谷氨酸，表明14C已掺入内源性池中。7天时肝脏中残留的部分放射性可通过化学方法转化为5-硝基苯并咪唑，表明存在与药物相关的大分子残留物。然而，给大鼠喂食放射性标记的牛肝脏的数据表明，该残留物的生物利用度极低，因此与坎苯达唑本身相比，其毒理学关注程度要低得多。
