Sulfadiazine sodium

Sulfadiazine is a sulfonamide antibiotic that inhibits the growth of Gram-positive and Gram-negative bacteria.^1,2,3,4 It inhibits dihydropteroate synthase (DHPS), which converts a pteridine and 4-aminobenzoic acid to dihydropteroate, an intermediate in folate biosynthesis.¹ Sulfadiazine inhibits recombinant P. carinii DHPS (IC₅₀ = 0.19 μM). It is active against clinical isolates of M. tuberculosis (MIC₉₀ = 10 mg/L) and of N. meningitidis (MICs = 5-2,000 mg/L).^2,3 Sulfadiazine is also active against A. pleuropneumoniae, S. choleraesuis, S. typhimurium, P. multocida, S. equi, and S. suis (MIC₉₀s = <0.5 mg/ml for all) when used in combination with trimethoprim .⁴ In vivo, sulfadiazine (40 mg/kg per day) increases survival in a mouse model of lethal T. gondii infection when administered in combination with pyrimethamine .⁵ Formulations containing sulfadiazine have been used in the treatment of rheumatic fever and various infections, and, in a dual treatment with pyrimethamine, to treat toxoplasmosis.

1.Hong, Y.-L., Hossler, P.A., Calhoun, D.H., et al.Inhibition of recombinant Pneumocystis carinii dihydropteroate synthetase by sulfa drugsAntimicrob. Agents Chemother.39(8)1756-1763(1995) 2.Ameen, S.M., and Drancourt, M.In Vitro Susceptibility of Mycobacterium tuberculosis to Trimethoprim and Sulfonamides in FranceAntimicrob. Agents Chemother.57(12)6370-6371(2013) 3.Wiggins, G.L., McLaughlin, J.V., Bickham, S.T., et al.Susceptibility of Neisseria meningitidis strains from the civilian population to sulfadiazine, penicillin, and rifampinAppl. Microbiol.20(6)893-898(1970) 4.Salmon, S.A., Watts, J.L., Case, C.A., et al.Comparison of MICs of ceftiofur and other antimicrobial agents against bacterial pathogens of swine from the United States, Canada, and DenmarkJ. Clin. Microbiol.33(9)2435-2444(1995) 5.Martins-Duarte, ?.S., de Souza, W., and Vommaro, R.C.Toxoplasma gondii: The effect of fluconazole combined with sulfadiazine and pyrimethamine against acute toxoplasmosis in murine modelExp. Parasitol.133(3)294-299(2013)