TREATMENT OF TRYPANOSOMIASIS. 27 



V. TREATMENT WITH A COMBINATION OF DRUGS. 



A number of investigators who have failed to secure good results 

 in the treatment of trypanosomiasis by single drugs have sought by a 

 combination of two or more to obtain better ones. Some encouragement 

 was given to this idea from the fact that in treating animals infected 

 with trypanosornata, which, for example, had been injected with certain 

 of the dyes or with arsenic compounds and in which dye fast or arsenic 

 fast strains of trypanosornata had developed, injections of antimony 

 seemed more successful owing to the fact that the parasites were not 

 antimony fast. Also, certain drugs which by themselves were inactive 

 against trypanosornata, for example, compounds of mercury or picric acid, 

 when used in combination were supposed to be effective. A large number 

 of experiments have been performed with these various combinations of 

 drugs, but usually with little more definite success than with the 

 remedies employed singly. The following may be mentioned among the 

 combinations of drugs which have been largely employed: (1) Atoxyl 

 'and various dyes; (2) atoxyl and bichloride of mercury; (3) atoxyl and 

 tartar emetic; (4) atoxyl and orpiment. 



TREATMENT WITH ATOXYL AND ARSENIC SULPHIDE ( ORPIMENT.) 



Laveran and Thiroux found that a combination of trisulphide of arsenic or 

 precipitated orpiment with atoxyl gave encouraging results in the treatment of 

 guinea pigs infected with trypanosomiasis. 



Thiroux and Teppaz treated four horses in this manner, apparently successfully, 

 as all were cured and under observation for six months. The authors state that 

 the animals were infected with a species of trypanosoma other than the one caus- 

 ing siirra. Two of the horses were treated with the sulphide alone, neither of 

 these being infected with the surra parasite. Both recovered. 



Holmes from India has also reported favorable results with the combined atoxyl 

 and orpiment treatment. Seven guinea pigs and two rabbits infected with trypa- 

 nosornata received atoxyl and orpiment. In no instance did the trypanosornata 

 reappear in the blood after the first injection of atoxyl. However, four of the 

 guinea pigs died during the period of observation — three months. In the three 

 which lived, four, six and seven doses of the drug, respectively, were given. Seven 

 ponies were also treated with atoxyl and orpiment, given alternately with an 

 interval of one day between each dose. In four, the author reports the treatment 

 to have been successful. Two of the animals of this series and four other ponies 

 not included in this series died of the treatment. One relapsed and was treated 

 with atoxyl, orpiment and tartar emetic for fifteen days and was stated to be 

 cured. Six other ponies were treated with a combination of atoxyl and tartar 

 emetic plus orpiment and sodium arsenate. In three of this series the results 

 were not successful. A number of animals showed relapses before they were cured. 

 The doses of orpiment employed were much smaller than those recommended by 

 Laveran and Thiroux, who administered up to 30 grams. The maximum dose 

 employed by Holmes was 3 grams of commercial arsenious sulphide of a light 

 yellow color. S. H. Gaiger has reported on the treatment of camel surra with red 

 and yellow orpiment. The results were entirely unsatisfactory. In one camel 

 treated with atoxyl and orpiment the result also was not successful. 



