TREATMENT OF TOXOPLASMOSIS

Screening tests of various kinds of compounds were carried out with the purpose of obtaining new drugs for toxoplasmosis. Compounds tested were 66 pyrimidine derivatives, 14 guanidine derivatives, 11 triazine derivatives, 12 sulfone derivatives, 1 amidine derivatives and 4 sulfadrugs. Mice inoculated with 100,000 Toxoplasmas of RH strain were used for the tests. The compounds to be tested were given intraperitoneally for five days successively, starting one day before the inoculation. The dose was 1/15 amount of LD50 of each compound. The effect of the compound was evaluated by difference in survival days between the test and the control animals. None of the derivatives of pyrimidine, guanidine, triazine, amidine and sulfa-drugs so far tested was proved to be more effective than pyrimethamine. The average survival period of the animals treated with pyrimethamine was twice as long as that of the control groups. Among the sulfone derivatives, 4-Nitro-4'-formylamino-diphenylsulfone and 4-Nitro-4'-acetoamino-diphenylsulfone seemed to be a little more effective than pyrimethamine regarding prolongation of the survival period. 4-Nitro-4'-formylamino-diphenylsulfone was most effective, i.e., 2 out of 6 mice treated with oral administration of this derivative were considered to be cured. By these results it was expected that 4-Nitro-4'-formylamino-difenylsulfone might be effective in treatments of human toxoplasmosis. (Author)