Synovial fluid and plasma concentrations of tedizolid in patients with osteoarthritis infected with Staphylococcus aureus effectively determined with fluorescence detection

BACKGROUND: Tedizolid is a new oxazolidinone antibiotic with high potency for the treatment of infections caused by methicillin-resistant Staphylococcus aureus and other species. CASE PRESENTATION: Two patients with osteoarthritis (women aged 79 and 73 years, cases 1 and 2, respectively) infected with S. aureus were successfully treated with tedizolid after administration of 200 mg once daily via intravenous infusion. The synovial fluid and plasma concentrations of tedizolid during surgery in case 1 at day 7 were 2.1 and 1.6 µg/mL, respectively, yielding a ratio of synovial fluid/plasma of 130%. Those in case 2 at day 2 were 2.9 and 3.3 µg/mL, respectively, corresponding to a ratio of synovial fluid/plasma of 88%. CONCLUSIONS: These results imply very similar concentrations of tedizolid in the synovial fluid and plasma of osteoarthritis patients with acute S. aureus infection.