EFFECTIVENESS AND TOLERABILITY OF PROLONGED LINEZOLID THERAPY FOR CHRONIC OSTEOMYELITIS

Abstract

Although linezolid has been used in the therapy of osteoarticular infections (OI), there is little information about its effectiveness and safety in prolonged therapy for OI.

Therefore the aim of our study was to assess the effectiveness and tolerability in OI and retrospectively evaluate multi-resistant gram-positive OI treated with linezolid 600 mg bid orally.

Between January 2003 and January 2007, 20 patients (10 men, mean age: 65 years) with 23 episodes of OI (19 of them associated with implants including 16 prosthetic joints) were treated with linezolid. In all but one episode, vitamin B6 was administered. Five were diabetic and 1 had renal insufficiency. All but two cases had infections due to multi-resistant coagulase-negative staphylococci. The median duration of therapy was 12.3 weeks (range 4–36 weeks). In 9 episodes the implant was removed. At the end of the therapy, response was observed in 22/23 (95.6%) of the episodes, and at the follow-up 10 relapses occurred (median duration: 1 month) resulting in an overall successful rate of cure of 12/23 (52.2%). The cure rate in episodes with and without implant removal was 6/9 (66.7%) and 3/10 (30%), respectively, while in the cases without implant 3/4 (75%). Adverse events that required drug discontinuation were observed in 10 (43.5%) episodes: anemia in 6/10 (60%), gastrointestinal in 6/10 (60%), lactic acidosis in two, teeth pigmentation in two and optic neuritis in one. Risk factors associated with secondary effects were: older age, diabetes mellitus and renal insufficiency. One patient developed anemia after one month; linezolid was stopped and restarted with vitamin B6 and no anemia was observed after 9 months of therapy.

Linezolid may be useful in multi-resistant gram-positive OI, especially when the implant is removed. However, with prolonged therapy, side effects are common, thus close monitoring for severe complications is needed.