UM School of Medicine Researchers Find No Benefit for Treatment Used to Avoid Surgery for Abdominal Aortic Aneurysm

Findings Could Lead to Changes in Practice for Life-Threatening Vascular Condition

A new landmark study by researchers at the University of Maryland School of Medicine (UMSOM) found that patients with a vascular condition, called abdominal aortic aneurysm, received no benefits from taking a common antibiotic drug to reduce inflammation. Patients who took the antibiotic doxycycline experienced no reduction in the growth of their aneurysm over two years compared to those who took a placebo, according to the study published today in the Journal of the American Medical Association (JAMA). The finding could lead doctors to stop prescribing the drug as a way to prevent small aneurysms from growing larger and bursting.

“This study provides strong evidence that doxycycline is of no benefit for patients with small abdominal aortic aneurysms in terms of preventing their growth. Health care providers should take note of the finding and stop using this as a prophylactic treatment,” said corresponding author Michael Terrin, MDCM, MPH, Professor of Epidemiology and Public Health at UMSOM. Researchers from the University of Nebraska Medical Center, the University of Wisconsin School of Medicine and Public Health and Vanderbilt University School of Medicine also had leadership roles in the study.

Abdominal aortic aneurysm is a swelling or ballooning that occurs in the major blood vessel (aorta) that supplies blood from the heart to the lower half of the body. It affects about 3 percent of older Americans, most commonly men and smokers. The condition can cause fatal internal bleeding if the aneurysm grows large enough to burst. Small aneurysms frequently cause no symptoms and are often detected when an abdominal ultrasound or CT scan is performed for other reasons. Doctors usually monitor the growth of the aneurysm and sometimes opt to prescribe doxycycline in an effort to forestall surgery in higher-risk patients. This practice was based on earlier research suggesting that certain antibiotics reduce inflammation that contributes to aneurysm growth.

The JAMA study involved 254 patients with small aneurysms who were randomly assigned to take either 100 milligrams of doxycycline twice daily or a placebo for two years; CT scans performed at the beginning of the study and on follow-up found no differences in aneurysm growth between those who took the drug and those who took the placebo. Study participants were mostly white and male with an average age of 71 years.

“Randomized clinical trials are essential when it comes to answering important clinical questions,” said Dean E. Albert Reece, MD, PhD, MBA, who is also Executive Vice President for Medical Affairs, UM Baltimore, and the John Z. and Akiko K. Bowers Distinguished Professor, University of Maryland School of Medicine. “This finding will help guide doctors to avoid an unnecessary treatment for a common condition associated with aging.” 

About the University of Maryland School of Medicine

Now in its third century, the University of Maryland School of Medicine was chartered in 1807 as the first public medical school in the United States. It continues today as one of the fastest growing, top-tier biomedical research enterprises in the world -- with 45 academic departments, centers, institutes, and programs; and a faculty of more than 3,000 physicians, scientists, and allied health professionals, including members of the National Academy of Medicine and the National Academy of Sciences, and a distinguished two-time winner of the Albert E. Lasker Award in Medical Research.  With an operating budget of more than $1.2 billion, the School of Medicine works closely in partnership with the University of Maryland Medical Center and Medical System to provide research-intensive, academic and clinically based care for nearly 2 million patients each year. The School of Medicine has more than $540 million in extramural funding, with most of its academic departments highly ranked among all medical schools in the nation in research funding. As one of the seven professional schools that make up the University of Maryland, Baltimore campus, the School of Medicine has a total population of nearly 9,000 faculty and staff, including 2,500 student trainees, residents, and fellows. The combined School of Medicine and Medical System (“University of Maryland Medicine”) has an annual budget of nearly $6 billion and an economic impact more than $15 billion on the state and local community. The School of Medicine faculty, which ranks as the 8th highest among public medical schools in research productivity, is an innovator in translational medicine, with 600 active patents and 24 start-up companies. The School of Medicine works locally, nationally, and globally, with research and treatment facilities in 36 countries around the world. Visit medschool.umaryland.edu