Q: Which antibiotic is suggested in the management of Abdominal Aortic Aneurysm (AAA)?


Answer: Doxycycline

Historically, it was postulated that AAA expansion may be due to the result of Chlamydia pneumoniae infection, and antibiotics were suggested to attenuate their expansion. Though some animal models and small studies have shown possible positive impact but so far evidence is extremely weak for its use as a standard of care in humans.


References:

1. Chung AW, Yang HH, Radomski MW, van Breemen C. Long-term doxycycline is more effective than atenolol to prevent thoracic aortic aneurysm in marfan syndrome through the inhibition of matrix metalloproteinase-2 and -9. Circ Res 2008; 102:e73.

2. Preoperative treatment with doxycycline reduces aortic wall expression and activation of matrix metalloproteinases in patients with abdominal aortic aneurysms. J Vasc Surg 2000; 31:325.

3. Baxter BT, Pearce WH, Waltke EA, et al. Prolonged administration of doxycycline in patients with small asymptomatic abdominal aortic aneurysms: report of a prospective (Phase II) multicenter study. J Vasc Surg 2002; 36:1. 

4. Petrinec D, Liao S, Holmes DR, et al. Doxycycline inhibition of aneurysmal degeneration in an elastase-induced rat model of abdominal aortic aneurysm: preservation of aortic elastin associated with suppressed production of 92 kD gelatinase. J Vasc Surg 1996; 23:336. 

5. Clinical trial of doxycycline for matrix metalloproteinase-9 inhibition in patients with an abdominal aneurysm: doxycycline selectively depletes aortic wall neutrophils and cytotoxic T cells. Circulation 2009; 119:2209. 

6. Meijer CA, Stijnen T, Wasser MN, et al. Doxycycline for stabilization of abdominal aortic aneurysms: a randomized trial. Ann Intern Med 2013; 159:815.