Diaziquone (NSC-182986) is a water-soluble synthetic azacyclic benzoquinone that enhances penetration of the blood-brain barrier, has antitumor activity, and is used in the treatment of extreme renal failure.

Diaziquone (5000 ng/mL) is associated with prolonged aplasia and rare instances of bone marrow necrosis, but only mild extramedullary toxicity. One- and three-hour treatments produced little cytotoxicity for hematopoietic versus marrow stromal cells. After six-hour treatments with this dose, marrow was depleted of CFU-Mix, BFU-E, and CFU-GM, but produced CFU-GM in LTMCs, indicating an ongoing input of CFU-GM from a surviving pre-CFU-Mix population. Diaziquone (150 ng/mL; 3 to 7 days) elimination of the latter may be inferred from the absence of CFU-GM in the LTMCs exposed.[4]

Diaziquone (0.1 mg/day; injection; 4 days) applied topically in Vanicream, Plastibase, or DMSO inhibited tumor growth at day 20 by 66, 86, and 43%, respectively, and cured animals of the skin tumor at a dose of 0.5 mg/day. Diaziquone administered i.p. at 0.5 mg/day for 4 days was lethal to rats, and at 0.1 mg/day it produced 93% inhibition of tumor growth at day 20. Diaziquone was applied topically at 0.1 mg/day for 4 days in Plastibase-cured rats of advanced tumors when treatment was begun 12 days after injection of tumor cells. The area under the plasma radioactivity time curve over 5 h for a single 0.64-mg dose of topically applied [ring-14C]diaziquone in DMSO was 0.01% that of the same dose of [ring-14C]diaziquone administered i.p. in non-tumored rats. The decrease in WBC count following topical application of diaziquone at a dose of 0.1 mg/day for 4 days, compared to the same dose of diaziquone administered i.p., was 62% in Vanicream, 81% in Plastibase and 33% in DMSO. Topical diaziquone was non-toxic to normal skin in the rat and in the domestic pig. It is concluded that topical application of diaziquone offers a therapeutic advantage over systemic treatment for metastatic cancer of the skin.[2]