Tedizolid (Synonyms: DA 7157, TR-700)

Tedizolid is an oxazolidinone antimicrobial agent with MIC50 value of 0.5 μg/ml for MSSA, MRSA, VR E. faecium and VR E. faecalis and 0.25 μg/ml for MSSE, MRSE, PSSP and PRSP [1].

The resistant Gram-positive infection is a serious global health problem. For instant, the methicillin-resistant S. aureus (MRSA) has spread all over the world with rates ranging from 18 to 26 cases among 100,000 people. Besides that, there come out a serious of resistant strains such as the linezolid-resistant S. aureus (LRSA) and the vancomycin-resistant S. aureus (VRSA). Due to the unfavorable outcomes of the existed antibiotics, alternative treatments have been developed. Tedizolid is a synthetic antibiotic that works based on the inhibition of protein synthesis. It binds to the 50S ribosome and inhibits the formation of the 70S complex [1].

Tedizolid showed potent bacteriostatic activity against many resistant Gram-positive pathogens such as MSSA, MRSA, S. pyogenes and S. pneumoniae. For the enterococcal and staphylococcal isolates, tedizolid displayed more than 4-fold higher potency than that of linezolid. It also showed inhibitory effects on a panel of 169 linezolid-resistant staphylococcal isolates with 79.2% inhibition at concentration of ≤ 4μg/ml. The MIC values of tedizolid against linezolid-resistant staphylococci were in a range from 0.06 to 16 mg/L. Besides that, tedizolid was found to be the inhibitors of human monoamine oxidase with IC50 values of 8.7 and 5.7 μM for MAO-A and MAO-B, respectively [1, 2 and 3].

When treated in vivo, tedizolid was the active moiety converted from the pro-drug tedizolid phosphate. It was found that granulocytes could affect the antistaphylococcal effect of tedizolid. In neutropenic mice, the administration of tedizolid for 24 hours or 48 hours caused ED50 values of 25.2 and 35.7 mg/kg/day, respectively [1 and 4].

References:
[1] Kanafani Z A, Corey G R.  Tedizolid (TR-701): a new oxazolidinone with enhanced potency. Expert opinion on investigational drugs, 2012, 21(4): 515-522.
[2] Rodríguez-Avial I, Culebras E, Betriu C, et al.  In vitro activity of tedizolid (TR-700) against linezolid-resistant staphylococci. Journal of antimicrobial chemotherapy, 2012, 67(1): 167-169.
[3] Flanagan S, Bartizal K, Minassian S L, et al.  In vitro, in vivo, and clinical studies of tedizolid to assess the potential for peripheral or central monoamine oxidase interactions. Antimicrobial agents and chemotherapy, 2013, 57(7): 3060-3066.
[4] Louie A, Liu W, Kulawy R, et al.  In vivo pharmacodynamics of torezolid phosphate (TR-701), a new oxazolidinone antibiotic, against methicillin-susceptible and methicillin-resistant Staphylococcus aureus strains in a mouse thigh infection model. Antimicrobial agents and chemotherapy, 2011, 55(7): 3453-3460.