Background and Purpose— Fluoroquinolone use is associated with an increased risk of aortic aneurysm and dissection. We investigated this risk of arterial wall injury on intracranial arteries, given the similar pathophysiological mechanisms for aneurysm and dissection in both types of arteries. Methods— A case-time-control study was conducted using French National Insurance databases covering >60 million inhabitants. Cases were aged ≥18 years with first ruptured intracranial aneurysm and dissection between 2010 and 2015. For each case, fluoroquinolone use was compared between the exposure-risk window (day 30–day 1 before the outcome) and matched control windows (day 120–day 91, day 150–day 121, and day 180–day 151) and adjusted for time-varying confounders; potential time-trend for exposure was controlled using an age- and sex-matched reference group. Amoxicillin use was studied similarly for indication bias controlling. The potential excess of risk conveyed by fluoroquinolones was assessed by the ratio of OR for fluoroquinolones to that for amoxicillin. Results— Of the 7443 identified cases, 75 had been exposed to fluoroquinolones in the prior 180 days, including 16 in the 30-day at-risk window (385/97 cases exposed to amoxicillin, respectively). The adjusted OR for fluoroquinolones was 1.26 (95%CI, 0.65–2.41) and that for amoxicillin of 1.36 (95% CI, 1.05–1.78). Ratio of OR for fluoroquinolones to that for amoxicillin was estimated at 0.92 (95% CI, 0.46–1.86). Result was similar when extending outcome definition to unruptured events (ratio of OR for fluoroquinolones to that for amoxicillin, 0.97 [95% CI, 0.61–1.53]). Conclusions— This study did not evidence an excess of risk of intracranial aneurysm or dissection with fluoroquinolone use.< Leer menos