Biological activity of diethyldithiocarbamate (Ditiocarb, Imuthiol) in an animal model of retrovirus-induced immunodeficiency disease and in clinical trials in patients with HIV infection. The Ditiocarb Study Group.

Diethyldithiocarbamate (Ditiocarb) is a drug with diverse biological activities suggesting that it may have multiple, clinical uses. Thus, it is an inhibitor of such enzymes as cytochrome P450, it is a chelating agent for nickel and cadmium, it is a free-radical scavenger and finally, it is an immunomodulator. As such, it can restore the immune responses of immunosuppressed mice. In the murine retrovirus-induced immunodeficiency disease (LP-BM5 in C57 black 10 mice), it can prevent the development of disease when given from the day of virus inoculation until 2 weeks after virus inoculation. In addition, it can reverse disease manifestations including lymphadenopathy when started as late as 10 weeks after virus inoculation. Associated with these effects is a reduction in mortality from 100 percent to between 0 and 10 percent. When drug is stopped however, disease progression resumes. In man, Ditiocarb has been used in a series of open, non-randomized as well as randomized prospectively-controlled clinical trials in patients with HIV infection. Three randomized placebo-controlled studies have been conducted. In the largest of these, involving 389 patients, Ditiocarb was shown to be safe, non-toxic and effective. Thus, there was a 62 percent reduction in new opportunistic infections (OI) in all of the treated patients, a 50 percent reduction in ARC patients and an 82 percent reduction in AIDS patients. When new and recurrent OI and other events indicating progression were taken together, there were 17 events in 193 treated patients and 42 events in 196 placebo control patients. Statistically significant reductions in these events were seen in ARC patients, AIDS patients and all patients.(ABSTRACT TRUNCATED AT 250 WORDS)