IMPORTANT NOTE: JAAPA CME activities consist of 2 articles. To obtain credit, you must also read
Ciliary injection: A differential diagnosis for the patient with acute red eye; the post-test will include questions related to both articles. AAPA Fellow members should complete and submit the post-test on the AAPA Web site by going to
www.aapa.org and searching for keyword
JAAPA post-tests. All others may complete and submit the post-test online at no charge at
www.mycme.com. To obtain 1 hour of AAPA Category I CME credit, PAs must receive a score of 70% or better on each test taken.
KEY POINTS
■ In July 2008, the FDA issued a black box warning for all fluoroquinolone antimicrobials. The action was in response to increased postmarketing reports of fluoroquinolone-induced tendinopathy and rupture. In addition, drug manufacturers are required to provide a patient medication guide that highlights the risk of this rare but potentially serious complication.
■ The exact mechanism of fluoroquinolone-induced tendinopathy is likely multifactorial and related to the physiology of the tendon itself, the affinity of fluoroquinolones for connective tissue, and the resulting increased apoptosis.
■ The risk of tendinopathy and rupture directly associated with the use of fluoroquinolone antimicrobials is increased approximately 3-fold in the average population and increases to at least 6-fold in patients older than 60 years who are also using corticosteroids.
■ Symptoms of fluoroquinolone-induced tendinopathy include pain, swelling, and inflammation of the tendon at one or multiple sites.
Patients should be instructed that if they experience any of these symptoms, they should stop the medication, avoid exercise, and report to their health care provider.
Fluoroquinolones are broad-spectrum antibiotics with bactericidal activity against a variety of aerobic and anaerobic organisms. They have been used to treat a wide range of bacterial infections in the United States since the 1980s. In July 2008, the FDA issued a black box warning in response to increased postmarketing reports of fluoroquinolone-induced tendinopathy and rupture. In addition, drug manufacturers are now required to provide a patient medication guide that highlights the risk of this rare but potentially serious complication.1 An increased understanding of which patients may be at greater risk and how to recognize the symptoms will enable clinicians to more effectively weigh the risks and benefits of prescribing these antimicrobials.
FLUOROQUINOLONES
The first quinolone compound was discovered inadvertently by George Y. Lesher, PhD, in 1962 when nalidixic acid was identified as a by-product of chloroquine synthesis.2 Subsequent research enhanced the understanding of its mechanism of action, which led to the prolific development of the fluoroquinolone antimicrobials.
Fluoroquinolones bind to the bacterial enzymes DNA gyrase (topoisomerase II) and topoisomerase IV, forming complexes that prevent supercoiling of the bacterial DNA, and ultimately hinder DNA replication within the bacterium.2 Fluoroquinolones are used increasingly to treat various respiratory, genitourinary (GU), gastrointestinal (GI), and skin infections. In 1988, fluoroquinolones were prescribed for 0.8 of every 100 persons annually. Just 10 years later, fluoroquinolone prescriptions increased to 5.5 per 100 persons annually.3 In addition, although the overall number of prescriptions for antibiotics in the United States did not significantly change between 1995 and 2002, the number of health care visits at which a fluoroquinolone antimicrobial was prescribed increased from 7 million to 22 million.4
The most commonly used fluoroquinolone antimicrobials in the United States today are ciprofloxacin, levofloxacin, moxifloxacin, and gemifloxacin (Table 1). Other fluoroquinolone antimicrobials were withdrawn after postmarketing reports of serious adverse events (gatifloxacin, because of dysglycemia; grepafloxacin, because of cardiovascular toxicity; and trovafloxacin, because of hepatotoxicity).5
