WASHINGTON—To fight the rising number of drug-resistant infections, doctors in Veterans Affairs (VA) hospitals are more frequently turning to last-resort antibiotics, known as polymyxins, which can cause serious kidney damage, according to a new study in the journal PLoS ONE. Their rising use also may increase bacterial resistance to these drugs, leaving doctors, in some cases, with no treatment options.
The peer-reviewed study looks at the use of polymyxins, which were discovered more than 50 years ago but went out of favor as better alternatives became available. The authors are physicians and researchers with the University of Utah and the VA Salt Lake City Health Care System.
"Because the drugs can produce such damaging side effects, doctors are typically quite reluctant to use polymyxins. We only reach for them when we have no other choice," said Dr. Makoto Jones, one of the authors.
Despite this common hesitation to prescribe these drugs, Dr. Jones and his colleagues found that their use increased by 25 percent between 2005 and 2010. The data was derived from detailed electronic records from individual patients at 127 VA centers over the five-year period. The paper also found a more than four-fold increase in use of another antibiotic called tigecycline, which is also prescribed to treat multidrug-resistant infections.
The authors note that use of these drugs in VA medical centers is still low overall, despite the increase seen in their study. There has not been a comparably comprehensive study of polymyxin and tigecycline use in non-VA hospitals.
"The absence of new safe and effective antibiotics to treat serious and life-threatening infections is a particular cause for concern," the authors wrote in the PLoS ONE article, entitled, "Drugs of Last Resort? The Use of Polymyxins and Tigecycline at U.S. Veterans Affairs Medical Centers, 2005-2010."
This study bolsters anecdotal evidence reported by physicians. According to a 2011 survey of 562 infectious diseases doctors conducted via the Emerging Infections Network and recently published in the journal Clinical Infectious Diseases, 64 percent have prescribed polymyxins within the past year. Sixty-three percent of respondents reported caring for a patient with an infection resistant to all available antibacterials and 56 percent observed that the number of these untreatable infections is increasing.[i] Most of the physicians surveyed in 2011 were from non-VA hospitals.
"We need policies to overcome the challenges stifling the development of new antibiotics," said Sharon Ladin, director of the Pew Health Group's Antibiotics and Innovation Project, which funded the study. "These hard-to-treat infections are a special threat for the many military personnel injured in combat, including those recently discharged veterans who suffer prolonged battles with superbugs."
The Pew Health Group's Antibiotics and Innovation Project is advocating for measures to incentivize the development of new antibiotics. It has called on Congress to include in its reauthorization of the Prescription Drug User Fee Act of 2012 the provisions that comprised the Generating Antibiotic Incentives Now Act (H.R. 2182, S. 1734), bipartisan legislation that would provide companies developing drugs to treat serious or life-threatening bacterial infections with an extra five years of exclusive rights to market those products.
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The Pew Health Group conducts rigorous research to form pragmatic policies that prevent unnecessary health risks. It is part of the The Pew Charitable Trusts, a nonprofit organization that applies a rigorous, analytical approach to improve public policy, inform the public and stimulate civic life. Learn more at www.pewhealth.org.
[i]Adam L. Hersh et al., “Unmet Medical Need in Infectious Diseases,” Clin Infect Dis. (2012) doi: 10.1093/cid/cis275