Pharmacosafety of fluoroquinolone and macrolide antibiotics in the clinical care of patients with myasthenia gravis

Abstract

Introduction/Aims Anecdotal case reports have suggested a potential association of fluoroquinolones and macrolides with myasthenia gravis (MG) exacerbation, prompting warnings against the use of these drugs in this population. However, large‐scale and reliable population‐based data that demonstrate this association are lacking. This study aims to examine the association between outpatient treatment with fluoroquinolones or macrolides and MG‐related hospitalization. Methods A retrospective cohort study consisting of adult MG patients was conducted using a large de‐identified healthcare claims database. Antibiotic prescription claims were identified, and MG‐related hospitalizations were assessed at 15, 30, and 90 days after the date of prescription. We used mixed effects survival regression with log‐logistic distribution and independent covariance matrix to estimate odds ratios (ORs) of hospitalization for each potentially exacerbating antibiotic using beta‐lactam as the reference and adjusting for covariates. Results Among 1556 MG patients receiving 894 fluoroquinolone prescriptions, 729 macrolide prescriptions, and 1608 beta‐lactam prescriptions during the study period, there was no difference in 15, 30, or 90‐day odds of MG‐related hospitalization between fluoroquinolone or macrolide users compared to prescribed beta‐lactams. However, estimates were higher for fluoroquinolones than macrolides, even after covariate adjustment (adjusted OR [aOR] 4.60, 95% confidence interval [CI] 0.55‐38.57 for fluoroquinolones and OR 0.56, 95% CI 0.32‐0.97 for macrolides, respectively, at 15 days). Discussion Fluoroquinolone and macrolide antibiotics are prescribed frequently to patients with MG. While statistical imprecision precludes a definitive conclusion, elevated ORs for fluoroquinolones raise the possibility of an underpowered association that merits further investigation.

Overview of Side-Effects of Antibacterial Fluoroquinolones: New Drugs versus Old Drugs, a Step Forward in the Safety Profile?

“…Recently, a retrospective cohort study included myasthenia gravis patients who received 894 prescriptions with FQs. In this study, Pham Nguyen et al [ 259 ] could not confirm the FQs’ association with myasthenia gravis exacerbation. Thus, the potential of FQs to cause the worsening of myasthenia gravis should not be excluded, and more studies are needed.…”

Fluoroquinolone-Associated Movement Disorder: A Literature Review

“…The black box warnings for all FQNs include the description of serious adverse reactions, such as tendinitis, tendon rupture, peripheral neuropathy, and central nervous system effects [ 17 ]. Additionally, FQNs should be avoided in patients with myasthenia gravis due to possible exacerbation of muscle weakness [ 18 ]. Interestingly, the inclusion of central nervous system side effects was described after many studies with enoxacin (second-generation FQN) showing a decrease in the seizure threshold [ 19 ].…”