Calls for further research into family of antibiotics to reduce risk of serious side effects

A review of the international use of a commonly prescribed family of antibiotics has found discrepancies in the safety data issued by regulatory bodies.

Fluoroquinolones are medicines that act against an extensive range of disease-causing bacteria, and for decades have been widely used as treatment for acute respiratory infections and urinary tract infections (UTIs).

In some rare cases, fluoroquinolones have been associated with serious side effects, including tendon ruptures, nervous system and psychiatric problems, aortic dissections and aneurysms.

As a result, many regulatory agencies recognize that the antibiotics potentially have a permanent toxicity. The U.S. Food and Drug Administration, European Medicines Agency, and UK's Medicines and Healthcare products Regulatory Agency (MHRA), all advise doctors not to prescribe them as a first line therapy or unless absolutely necessary.

However, a new study examining the global approach to fluoroquinolones has revealed some countries have not restricted its use.

Dr. Robert Baldock, from the School of Pharmacy and Biomedical Sciences at the University of Portsmouth, said, "What we found that was quite striking is that Australia, New Zealand, Japan and Canada don't have these warnings for disabling effects for fluoroquinolones.

"And so, what this paper does is examine the evidence that was used to make these policies in the first place, and as a result calls for a global harmonization of the safety warnings."

The paper, published in Expert Opinion on Drug Safety, is part of a collaborative project between several institutions including the University of Portsmouth, York College of Pennsylvania, University of South Carolina, and the City of Hope Comprehensive Cancer Center in Duarte, California.

It provides a clear picture of how fluoroquinolones are used globally, and provides a framework for regulatory agencies to address patient reports of serious side effects.

"As adverse reactions can be diverse and underreported, one of the challenges is identifying the number of serious adverse events there are, or have been," added Dr. Baldock.

"So many patients who report chronic fatigue, pain or psychiatric problems either remain undiagnosed or misdiagnosed, often with things like chronic fatigue syndrome.

"If regulatory bodies can resolve this issue, it could lead to more robust and universal safety data."

The authors also recommend manufacturers sponsoring pilot research to identify what causes a patient to suffer serious side effects after taking fluoroquinolones.

Dr. Cecilia Bove, from the Department of Biological Sciences at York College of Pennsylvania, added, "What we need is a strategy to mitigate these risks. And in doing so, we need the research to uncover the molecular causes of those adverse reactions to the antibiotics.

"With this information, we can determine strategies to mitigate the symptoms, and provide more data against the over-prescription of these drugs. That way we can continue to use fluoroquinolones and benefit from their bacteria-fighting capabilities when other strategies are not sufficient."