Tedizolid is the active moiety of the prodrug tedizolid phosphate, a next-generation oxazolidinone, with high potency against Gram-positive bacteria, including methicillin-resistant S aureus. It is FDA-approved at a dose of 200 mg orally or intravenously once daily for 6 days for the treatment of skin and soft tissue infection. Potential advantages over linezolid include increased potency against staphylococci and a longer half-life of 12 hours, allowing once-daily dosing. It may be associated with a decreased risk of marrow suppression; however, it has not been studied over a prolonged duration of therapy. It is thought to have a lower risk of serotonergic toxicity, but concomitant use with serotonin reuptake inhibitors has not been formally evaluated. Tedizolid is more highly protein-bound (70–90%) than linezolid (31%); there are no data on CSF penetration of tedizolid.
• Tetracycline Prevents bacterial protein synthesis by binding to the 30S ribosomal subunit Bacteriostatic activity against susceptible bacteria Infections caused by mycoplasma, chlamydiae, rickettsiae, some spirochetes • malaria • H pylori • acne Oral • mixed clearance (half-life 8 h) • dosed every 6 h • divalent cations impair oral absorption • Toxicity: Gastrointestinal upset, hepatotoxicity, photosensitivity, deposition in bone and teeth
Doxycycline: Oral and IV; longer half-life (18 h) so dosed twice daily; nonrenal elimination; absorption is minimally affected by divalent cations; used to treat community-acquired pneumonia and exacerbations of bronchitis • Minocycline: • Tigecycline:
IV; unaffected by common tetracycline resistance mechanisms; very broad spectrum of activity against Gram-positive, Gram-negative, and anaerobic bacteria; nausea and vomiting are the primary toxicities
MACROLIDES •ErythromycinPrevents bacterial protein synthesis by binding to the 50S ribosomal subunit Bacteriostatic activity against susceptible bacteria Community-acquired pneumonia•pertussis•corynebacterialandchlamydial infections Oral,IV•hepaticclearance(half-life1.5h)•dosedevery6h•cytochromeP450inhibitor•Toxicity: Gastrointestinal upset, hepatotoxicity, QTc prolongation
Clarithromycin: Oral; longer half-life (6 h) so dosed twice daily; added activity versus M avium complex, toxoplasma, and M leprae
Azithromycin: Oral, IV; very long half-life (68 h) allows for once-daily dosing and 5-day course of therapy of community-acquired pneumonia; does not inhibit cytochrome P450 enzymes
Telithromycin: Oral; unaffected by efflux-mediated resistance so is active versus many erythromycin-resistant strains of pneumococci; rare cases of fulminant hepatic failure • Linezolid Prevents bacterial protein synthesis by binding to the 23S ribosomal RNA of 50S subunit Bacteriostatic activity against susceptible bacteria Infections caused by methicillin-resistant staphylococci and vancomycinresistant enterococci Oral, IV • hepatic clearance (half-life 6 h) • dosed twice-daily • Toxicity: Duration-dependent bone marrow suppression, neuropathy, and optic co-administered with other serotonergic drugs (eg, selective serotonin reuptake inhibitors)