Oral fluoroquinolone use and risk of peripheral neuropathy

OBJECTIVE: To quantify the risk of peripheral neuropathy (PN) with oral fluoroquinolone (FQ) use. METHODS: We conducted a case-control study within a cohort of men aged 45 to 80 years in the United States followed from 2001 to 2011. Cases were defined as those with the first physician visit diagnosis of PN, polyneuropathy, or drug-induced polyneuropathy. Four controls were matched to each case by age, follow-up, and calendar time using density-based sampling. As a sensitivity analysis, we also quantified the risk of PN with finasteride use, a drug that is not expected to increase the risk of PN. Rate ratios (RRs) for current users of FQs were computed using conditional logistic regression, which was adjusted for chronic renal failure, chronic liver disease, hypothyroidism, postherpetic neuralgia, and the use of nitrofurantoin and metronidazole. RESULTS: We identified 6,226 cases and 24,904 controls. Current users of FQs were at a higher risk of developing PN (RR = 1.83, 95% confidence interval CI 1.49-2.27). Current new users had the highest risk (RR = 2.07, 95% CI 1.56-2.74). No risk was observed for current users of finasteride (RR = 1.21, 95% CI 0.97-1.51). CONCLUSIONS: Current users, especially new users of FQs, are at a higher risk of developing PN. Despite the increase in the use of FQs, clinicians should weigh the benefits against the risk of adverse events when prescribing these drugs to their patients.