TWSb is a water soluble trivalent organic antimonial of a new type, 50 times less toxic than tartar emetic (mouse), applicable by intramuscular and intravenous injection. In laboratory animals TWSb is therapeutically active in Trypanosoma congolense and T. brucei trypanosomiasis, in Litmosoides carinii filariasis and in Manson's schistosomiasis.
Seventy clinical cases of active schistosomiasis mansoni have been treated with various intensive intravenous and semi-intensive intramuscular dosage schedules. A one-to-three-day intensive treatment with TWSb has an immediate blocking effect on egg deposition. Immature eggs, numerous before treatment, were conspicuously absent in all of 35 cases submitted to rectal biopsy 2 to 21 days after treatment.
In 58 clinical cases of active schistosomiasis mansoni, TWSb permitted a safe 1-to-3-day intensive intravenous treatment with doses totaling 1.1 to 2.3 grams, resulting in 53 (91 per cent) presumptive cures, controlled up to 12 months after the treatment by rectal biopsy and feces examination. Five (9 per cent) of these 58 cases relapsed during the second to sixth post-treatment month. These 5 therapeutic failures received treatment with doses well within the tolerated range, i.e., with doses which can be safely increased.
Side effects of the intensive treatment were limited to alimentary vomiting, transitory benign skin rashes and rheumatoid pains toward the end of the treatment.
The detoxification of antimony realized in TWSb is particularly evident in electrocardiogram and blood pressure studies demonstrating that even massive doses have no significant cardiovascular effect. The following points suggest TWSb as a medication suited for the public health treatment of schistosomiasis:
the rapid treatment within 2 days;
the rapid blocking of egg deposition, probably within the first two post-treatment days;
the safety of the treatment;
the high presumptive cure rate of better than 90 per cent.