This case illustrates a novel screening protocol for linezolid-induced toxic optic neuropathy.PURPOSE
To present a case report and analysis of linezolid-induced optic neuropathies in adult patients to develop screening recommendations.CASE REPORT
A case report of optic neuropathy from extended use of linezolid illustrates its potential effects on vision. We conduct a retrospective analysis of 39 reported cases to derive a recommended screening protocol for linezolid-induced toxic optic neuropathy in adult patients. Of 39 reported adult cases, 32 presented with optic neuropathy within 90 to 365 days of treatment. Within this subset, the duration of linezolid dosage to first symptoms is 235 ± 71 days. Seven outliers either experienced optic neuropathy within the first 28 days or between 600 and 1125 days. Of the 33 cases that quantified visual recovery, 30 reported final binocular visual acuity equivalent to 20/40 or better when the medication was discontinued from 0 to 268 days after symptom onset. Recovery potential was reported over a period of 2 weeks to approximately 6 months after cessation. To evaluate the effect of cumulative dose, the data were separated into patients taking 600 mg twice daily and those at 600 mg once daily. At the higher dosage, a mean of 180 ± 96 days with a mean cumulative dosage of 216 ± 115 g was noted at first symptom, whereas at lower dosage, a mean of 201 ± 102 days was noted with a mean cumulative dose of 138 ± 69 g.CONCLUSIONS
We recommend screening adult patients within 1 month after initiating linezolid, followed by a subsequent evaluation every 30 to 60 days beginning 3 months from initiation. Substantial visual recovery is reported when linezolid is discontinued. Toxicity appears to be correlated to duration of treatment, rather than cumulative dose.