Which antibiotic class is associated with an increased risk of abdominal aortic aneurysm rupture?

Which antibiotic class is associated with an increased risk of abdominal aortic aneurysm rupture?

• A. Azithromycin
• B. Doxycycline
• C. Amoxicillin
• D. Fluoroquinolones

Answer: (D)

The main idea is that fluoroquinolones have a noteworthy, though not fully understood, association with weakening of the aortic wall, leading to an increased risk of abdominal aortic aneurysm rupture or dissection, especially in older patients or those with known aneurysms. This class includes drugs like ciprofloxacin and levofloxacin. Why this is the best answer: Fluoroquinolones can affect connective tissue by influencing collagen synthesis and degradation and may upregulate matrix metalloproteinases, which weaken the aortic wall. Regulatory agencies have issued warnings about ruptures or dissections with these antibiotics, and clinicians are advised to avoid them in patients with known aortic aneurysm when suitable alternatives exist. That risk profile is not shared by the other antibiotics listed. Brief context on the others: Azithromycin, doxycycline, and amoxicillin do not have a demonstrated, clinically significant association with abdominal aortic aneurysm rupture. Doxycycline is sometimes studied for aneurysm biology (e.g., MMP inhibition) but not linked to increasing rupture risk; azithromycin and amoxicillin have no established connection to aneurysm rupture in standard practice.

The main idea is that fluoroquinolones have a noteworthy, though not fully understood, association with weakening of the aortic wall, leading to an increased risk of abdominal aortic aneurysm rupture or dissection, especially in older patients or those with known aneurysms. This class includes drugs like ciprofloxacin and levofloxacin.

Why this is the best answer: Fluoroquinolones can affect connective tissue by influencing collagen synthesis and degradation and may upregulate matrix metalloproteinases, which weaken the aortic wall. Regulatory agencies have issued warnings about ruptures or dissections with these antibiotics, and clinicians are advised to avoid them in patients with known aortic aneurysm when suitable alternatives exist. That risk profile is not shared by the other antibiotics listed.

Brief context on the others: Azithromycin, doxycycline, and amoxicillin do not have a demonstrated, clinically significant association with abdominal aortic aneurysm rupture. Doxycycline is sometimes studied for aneurysm biology (e.g., MMP inhibition) but not linked to increasing rupture risk; azithromycin and amoxicillin have no established connection to aneurysm rupture in standard practice.