By Michael Raj and Dr. Janice Mann

Most of us, at some point in our lives, have been prescribed an antibiotic to treat an infection. And we’re lucky to have medications so readily available to treat infections that just a few generations ago were often fatal. But like most things in our modern lives, when it comes to antibiotics, we want them to act fast and be easy to take so we can get back to our busy routines. In fact, for antibiotics, we may think “the quicker, the stronger, the better” to cure what ails us, but there may be something amiss with that logic.

There are many different classes of antibiotics used to treat different types of bacterial infections. One class, called fluoroquinolones, is able to successfully treat a wide variety of infections and includes ciprofloxacin, moxifloxacin, levofloxacin, norfloxacin, and ofloxacin. They are often prescribed in Canada to treat urinary tract infections (also sometimes called bladder infections or UTIs) as well as to treat common respiratory infections like bronchitis or sinusitis. Fluoroquinolones are generally easy to take — requiring less frequent dosing than some other antibiotics — and they work well to clear these infections, making them a popular choice for health care providers. In fact, prescribing of this drug class increases each year.

But because a drug is easy to take and works well to treat an infection doesn’t always mean it’s the best choice. It’s also important to consider any potential harms that could result from taking the medication. And when it comes to fluoroquinolones, the list of possible side effects is lengthy, with a recent safety review by Health Canada finding that some of the side effects can even lead to disability long after the medication is finished. Side effects of fluoroquinolones can include tendonitis (inflammation of the tendons that join muscle to bone) or rupture of a tendon (a partial or complete tear of a tendon); effects on the nerves of the body, leading to symptoms such as chronic pain, anxiety, dizziness and confusion; an overly sensitive immune system; phototoxicity (a sunburn like reaction of the skin in response to light); and abnormal heart rhythms. These side effects can occur within hours to weeks after taking a fluoroquinolone and in rare cases may be permanent. Those most at risk appear to be children under the age of 18, adults over 60, and pregnant and nursing women.

So with these risks, and with other antibiotics available, why are fluoroquinolones still so widely used? To better understand this issue, CADTH — an independent agency that finds, assesses, and summarizes the research on drugs, medical devices, tests, and procedures — recently conducted a review to understand and explain the experiences and decision-making processes around the prescribing of antibiotics for specific types of infections. CADTH carefully searched the medical literature, reviewed clinical practice guidelines, and conducted a survey of primary care practitioners, including family physicians, nurse practitioners, and pharmacists.

MORE: TOPICAL NSAIDs: RIGHT WHERE IT HURTS

The review found that, in general, healthcare providers are aware of the risks posed by fluoroquinolones and the need to carefully balance the potential benefits of the medication with those risks. Family physicians, nurse practitioners, and pharmacists all voiced concern that fluoroquinolones may be over-prescribed and not always the appropriate choice. However, there are some factors that make it more likely for prescribers to choose fluoroquinolones — and patients saying that they are allergic to other antibiotics is an important one. Unfortunately, patients who believe they are allergic to other antibiotics often are not, and instead have experienced side effects of the medication that are normal, albeit unpleasant, such as an upset stomach. Determining whether a patient is truly allergic to other antibiotics can be a difficult and time-consuming task for health care providers, which makes fluoroquinolones seem like an attractive option for these patients. Another key reason for prescribing fluoroquinolones is the awareness of how effective they are in treating a wide variety of bacterial infections and uncertainty about whether the infection they are treating is resistant to other antibiotics. Along the same lines, fluoroquinolones are also chosen when other treatment options have already been tried. Health care providers may also opt for fluoroquinolones if they are concerned that a patient may not be able to successfully take an antibiotic that requires a more demanding schedule (that needs to be taken more often each day and for a longer period of time).

What do the findings of the CADTH review mean for patients, their health care providers and the Canadian health system?

As a patient, it’s important to be aware of the risks and benefits of taking fluoroquinolones if you have an infection and to discuss these with your health care provider. Knowing the difference between side effects and a true allergy to a particular antibiotic is important and can help ensure you’re receiving the antibiotic prescription that is best for you. Ask your health care provider for more information on this important issue. If you are taking a fluoroquinolone and experience any side effects, or if you have taken fluoroquinolones in the past and think you may be experiencing any long-term side effects of the medication, let your health care provider know.

Knowing the factors that may influence fluoroquinolone prescribing can help health care providers and the health care system address them. Health Canada has already reviewed the safety of fluoroquinolones, and is now recommending that the safety information for all fluoroquinolone products be updated and is working with manufacturers to do so. Evidence shows that policy changes, tailored education, and sharing information can all be effective in positively influencing antibiotic prescribing. Strategies to increase awareness of local antibiotic resistance patterns and of local, national, and international clinical practice guidelines may also help support optimal prescribing decisions.

Fluoroquinolones remain an important option for effectively treating some bacterial infections. But taking into consideration all of the important information and evidence before prescribing them will help ensure that we maximize the benefits of this medication while minimizing the risks.

For more information on CADTH and the review of FQ prescribing, visit www.cadth.ca, follow us on Twitter @CADTH_ACMTS, or contact a CADTH Liaison Officer in your region.

Michael Raj, BSc MHA is a consultant for CADTH’s Knowledge Mobilization and Liaison Program, and, Dr. Janice Mann BSc MD is a Knowledge Mobilization Officer at CADTH.