Cayman Sulfamethoxazole-d4

Sulfamethoxazole-d₄ is intended for use as an internal standard for the quantification of sulfamethoxazole (Item No. ) by GC- or LC-MS. Sulfamethoxazole is a sulfonamide antibiotic. It inhibits growth of E. coli (MIC = 10 μg/mL) and clinical isolates of methicillin-resistant S. aureus (MRSA; MICs = 25-50 μg/mL).^, Sulfamethoxazole, in combination with trimethoprim (Item No. ) at a ratio of 20:1, inhibits growth of MRSA in vivo in mice (MIC = 0.8 μg/mL; ED₅₀s = 6.4 and 9.6 mg/kg for two MRSA strains). In a mouse model of urinary tract infection with E. coli, a combination of sulfamethoxazole and trimethoprim decreases recurrent infection when administered for 10 days. Sulfamethoxazole acts by inhibiting dihydropteroate synthase (DHPS), which converts pteridine and 4-aminobenzoic acid (PABA; Item No. ) to dihydropteroate, an intermediate in folate biosynthesis. It inhibits recombinant P. carinii DHPS (IC₅₀ = 23 nM; K_i = 7.5 nM) and folate biosynthesis in situ by 48.6%. Formulations containing sulfamethoxazole and trimethoprim have been used to treat bronchitis, prostatitis, and urinary tract infections among other infectious conditions.

WARNING This product is not for human or veterinary use.