Outside experts were unable to draw conclusions
The accuracy of the current study is “extremely limited” by its design, according to Dr. Karsten Knobloch, a sports medicine physician in private practice in Hanover, Germany, who has reported on the risk of drug-induced tendon disorders.
“This is a case series only, which is a very strict limitation; therefore, the ability to generalize the data is also very limited,” he said in an interview. “In my view, the study does not add substantial data to support that third-generation [fluoroquinolones] are safer than the prior ones.”
Thomas Lodise, PharmD, PhD, who is a professor at the Albany College of Pharmacy and Health Sciences in New York, pointed out another barrier to determining the value of the new research .
“Without knowing how many received moxifloxacin and descriptors of patients at baseline by each drug, it is hard to draw any definitive results from the paper,” Dr. Lodise noted.
Study design and execution had limitations
The authors acknowledged the limitations in the study design and execution. In particular, reliance on an administrative claims database means that the accuracy of diagnoses cannot be validated. Further, the study sample size may not have been sufficient to estimate the rupture risk for individual fluoroquinolones, they wrote.
Despite these and additional limitations, the findings have merit, according to the authors, who noted that the information may be useful in personalizing antibiotic therapy for individual patients.
“Fluoroquinolone-induced tendon injury is a rare event, and managing risk for even rare adverse events depends on each case,” Dr. Chinen explained. The findings of this study together with previous studies indicate that third-generation fluoroquinolones may be a safer option with respect to risk of Achilles tendon rupture for some patients who can’t be prescribed beta-lactam antibiotics and for some conditions, such as Legionella pneumophila, he said.
To increase internal and external validity of the results, further research including prospective cohort studies in broader populations are necessary, Dr. Chinen stressed.
The authors, Dr. Lodise, and Dr. Knobloch, who is owner of SportPraxis in Hanover, Germany, reported no conflicts.