Are Fluoroquinolones Truly Associated with Increased Risk of Aortic Dissection?

BACKGROUND AND PURPOSE:

Recent observational studies have reported an association between fluoroquinolone and increased risk of aortic aneurysm or aortic dissection (AA/AD) | FDA has released a Drug Safety Communication addressing this risk
- However, previous studies did not consider the role of coexisting infections nor the effects of fluoroquinolones vs other antibiotics
Dong et al. (JAMA Intern Med)
- Estimated the risk of AA/AD associated with infections
- Assessed the comparative risk of AA/AD associated with fluoroquinolones vs other antibiotics with similar indication profiles

METHODS:

Nested case-control study (January 1, 2009, to November 30, 2015)
Data sources
- Nationwide population-based health insurance claims database
Exposures
- Infections and antibiotic use within a 60-day risk window before the occurrence of AA/AD
Study design
- Every incident case of AA/AD was matched with 10 control individuals based on age, sex, and follow-up duration using risk-set sampling
- Conditional logistic regression was used to estimate the odds ratios (ORs) comparing infections for which fluoroquinolones are commonly used vs no infection within a 60-day risk window before outcome occurrence | Adjustments made for baseline confounders and concomitant antibiotic use
- Fluoroquinolones were compared to other antibiotics with similar indication profiles within patients with indicated infections

RESULTS:

28,948 cases | 289,480 matched controls
- 71.37% male | Mean (SD) age 67.41 (15.03) years
There was an association between AA/AD and ‘any indication’ infection
- OR 1.73 (95% CI, 1.66 to 1.81)
However, fluoroquinolones were not associated with an increased AA/AD risk in patients with indicated infections when compared with
- Combined amoxicillin-clavulanate or combined ampicillin-sulbactam
  - OR 1.01 (95% CI, 0.82 to 1.24)
- Extended-spectrum cephalosporins
  - OR 0.88 (95% CI, 0.70 to 1.11)
Findings did not differ based on subgroup analysis

CONCLUSION:

Although fluoroquinolone use was associated with AA/AD, this association was no longer apparent when fluoroquinolones where compared to other antibiotics used for the same indication
A recent study by Gopalakrishnan et al. (JAMA Intern Med, 2020) reached similar conclusions
- Risk of AA/AD was slightly increased with fluoroquinolone use in pneumonia, compared to other antibiotics, but there was no association for patients with urinary tract infections
The results of these studies confirm the importance of adjusting for pre-existing infections when assessing antibiotic safety
The authors conclude

This study’s results emphasize the importance of considering coexisting infections while examining the safety of antibiotics using real-world data

Concern about AA/AD should not preclude patients with indicated infections from necessary treatment with fluoroquinolones