Sulfadiazine sodium belongs to the class of sulfonamide antibiotics that are used for veterinary purposes worldwide, mainly in pig production. Sulfadiazine sodium also used for toxoplasmosis[1][2].

In this study, the effectiveness of Sulfadiazine sodium and Pyrimetamine for the treatment of mice during acute infection with different atypical T. gondii strains was evaluated. Swiss mice were infected with seven T. gondii strainsl. The infected mice were treated with 10-640mg/kg per day of Sulfadiazine sodium, 3-200mg/kg per day of Pyrimetamine, or a combination of both drugs with a lower dosage. A descriptive analysis was used to assess the association between susceptibility to sodium and/or Pyrimetamine and the genotype. The TgCTBr4 and TgCTBr17 strains (genotype 108) presented lower susceptibility to sodium or Pyrimetamine treatment. The TgCTBr1 and TgCTBr25 strains (genotype 206) presented similar susceptibility to PYR but not sodium treatment. The TgCTBr9 strain (genotype 11) was the only strain with high susceptibility to treatment with both drugs [1].

[1]. Kopmann C, et al. Abundance and transferability of antibiotic resistance as related to the fate of sulfadiazine in maize rhizosphere and bulk soil. FEMS Microbiol Ecol. 2013 Jan;83(1):125-34. [2]. Silva LA, et al. Efficacy of sulfadiazine and pyrimetamine for treatment of experimental toxoplasmosis with strains obtained from human cases of congenital disease in Brazil. Exp Parasitol. 2019 Jul;202:7-14.