Safety of long-term use of linezolid: results of an open-label study.
OBJECTIVE
The objective of this study was to assess the long-term safety of linezolid in patients with chronic infections requiring treatment for ≥6 weeks. Enhanced monitoring for optic neuropathy was included to characterize the early development of this side effect and to identify ophthalmologic tests that might be valuable in early detection of this event.


METHODS
This was a multicenter, open-label, pilot study of patients aged ≥18 years on long-term linezolid therapy. Matched control patients were included for baseline assessment comparison. Patients were assessed at study entry, monthly while on treatment, at the end of treatment, and 30 days following the last dose. Aggregate ocular safety data were reviewed. Response to treatment was reported.


RESULTS
The study was terminated owing to slow enrollment. Twenty-four patients received linezolid; nine patients were included as matched controls. Linezolid was prescribed for a median of 80.5 days (range, 50-254 days). In patients with a reported clinical outcome, the majority were considered improved or cured. Common treatment-related adverse events (AEs) included anemia, peripheral neuropathy, polyneuropathy, vomiting, and asthenia, and were consistent with the known safety profile. Most AEs resolved or stabilized with discontinuation of treatment. Results of ophthalmologic tests in the one case adjudicated as probable linezolid-associated optic neuropathy revealed abnormal color vision, characteristic changes in the optic disk, and central scotomas in each eye.


CONCLUSIONS
In our small population, linezolid was generally well tolerated and AEs were consistent with the known safety profile. Extensive ophthalmologic testing of all 24 linezolid-treated patients identified one case adjudicated as probable, linezolid-associated optic neuropathy.
Section of Infectious Diseases, Medical College of Georgia, Georgia Regents University, Augusta, GA, USA.
Jose A
JA
Vazquez
UCLA Department of Ophthalmology, Jules Stein Eye Institute, Los Angeles, CA, USA.
Anthony C
AC
Arnold
Clinical Research, Global Innovative Pharmaceutical, Pfizer Inc., New York, NY, USA.
Robert N
RN
Swanson
Clinical Research, Global Innovative Pharmaceutical, Pfizer Inc., New York, NY, USA.
Pinaki
P
Biswas
Infectious Diseases Division, Santa Maria della Misericordia University Hospital, Udine, Italy.
Matteo
M
Bassetti
linezolid; optic nerve diseases; oxazolidinones; peripheral nervous system diseases; safety