In light of these results, the FDA issued an alert reminding healthcare professionals that linezolid is not approved for the treatment of catheter-related infections or infections caused by Gram-negative organisms, and that more appropriate therapy should be instituted whenever a Gram-negative infection is confirmed or suspected. Specific populations
In adults and children over the age of 12, linezolid is usually given every 12 hours, whether orally or intravenously. In younger children and infants, it is given every eight hours. No dosage adjustments are required in the elderly, in people with mild-to-moderate liver failure, or in those with impaired kidney function. In people requiring hemodialysis, care should be taken to give linezolid after a session, because dialysis removes 30–40% of a dose from the body; no dosage adjustments are needed in people undergoing continuous hemofiltration, although more frequent administration may be warranted in some cases. According to one study, linezolid may need to be given more frequently than normal in people with burns affecting more than 20% of body area, due to increased nonrenal clearance of the drug.Linezolid is in U.S. pregnancy category C, meaning there have been no adequate studies of its safety when used by pregnant women, and although animal studies have shown mild toxicity to the fetus, the benefits of using the drug may outweigh its risks. It also passes into breast milk, although the clinical significance of this (if any) is unknown.
Studies of the compounds structure–activity relationships led to the development of several subclasses of oxazolidinone derivatives, with varying safety profiles and antimicrobial activity. Two compounds were considered drug candidates: eperezolid (codenamed PNU-100592) and linezolid (PNU-100766). In the preclinical stages of development, they were similar in safety and antibacterial activity, so they were taken to Phase I clinical trials to identify any difference in pharmacokinetics. Linezolid was found to have a pharmacokinetic advantage—requiring only twice-daily dosage, while eperezolid needed to be given three times a day to achieve similar exposure—and therefore proceeded to further trials. The U.S. Food and Drug Administration (FDA) approved linezolid on 18 April 2000. Approval followed in Brazil (June 2000), the United Kingdom (January 2001), Japan and Canada (April 2001), Europe (throughout 2001), and other countries in Latin America and Asia.As of 2009, linezolid was the only oxazolidinone antibiotic available. Other members of this class have entered development, such as posizolid (AZD2563), ranbezolid (RBx 7644), and radezolid (RX-1741). In 2014, the FDA approved tedizolid phosphate, a second-generation oxazolidinone derivative, for acute bacterial skin and skin structure infection. Society and culture
Economics
Linezolid was quite expensive in 2009; a course of treatment may cost one or two thousand U.S. dollars for the drug alone, not to mention other costs (such as those associated with hospital stay). With the medication becoming generic the price has decreased.