Contezolid acefosamil sodium (MRX-4), a new and orally active oxazolidinone , is an antibiotic in study for complicated skin and soft tissue infections (cSSTI) caused by resistant Gram-positive bacteria. Contezolid acefosamil sodium (MRX-4) markedly reduces potential for myelosuppression and monoamine oxidase inhibition (MAOI) In Vitro Contezolid (MRX-I) is highly potent against all Grampositive clinical isolates of staphylococci, streptococci, and enterococci, including MDR organisms such as MRSA, methicilline-resistant Streptococcus epidermidis (MRSE), penicillin-resistant Streptococci (PRSP), and VRE. MCE has not independently confirmed the accuracy of these methods. They are for reference only. In Vivo Oral absorption of Contezolid (MRX-I) occurrs rapidly in mouse, rat, and dog, with peak plasma concentrations observed at 0.5−2.6 h postdose. In mouse, rat, and dog, respectively, PK parameters are determined as follows: dose-normalized C max /dose was 524, 1065, and 259 ng/mL/(mg/kg); dose-normalized AUC 0−t /dose was 1654, 3703, and 1664 ng•h/mL/(mg/kg); T 1/2 is 1, 1.5, and 3 h; and the oral bioavailability is 69%, 109%, and 37%. Contezolid (MRX-I) exhibits no obvious toxicity. Contezolid (MRX-I, 100 mg/kg, once daily) significantly reduced the bacterial load in lungs compared to the untreated early and late controls. MCE has not independently confirmed the accuracy of these methods. They are for reference only. Animal Model: BALB/c mice infected intranasally with M. tuberculosis Erdman. Dosage: 100, 50 (twice), 25 (twice) mg/kg. Administration: Gavage, once or twice daily, five days per week for four weeks. Result: Significantly reduced the CFU recovered from the lungs compared to the early and late control mice (P 0.05). Animal Model: Rats. Dosage: 20, 100, and 200/300 mg/kg/day. Administration: Orally twice daily. Result: No mortality was observed. Form:Solid IC50& Target:Oxazolidinone