On these GEITP pages, we deal with gene-environment interactions, and a major subset of this topic is gene-drug interactions: efficacy, therapeutic failure, dose-dependent adverse drug reactions (ADRs), and dose-independent ADRs. All of these categories constitute the TRAIT (phenotype). The patient’s response to each drug can be affected by his genotype (DNA sequence differences), epigenetic effects (DNA-methylation, RNA interference, histone modifications & chromatin remodeling), endogenous influences (e.g. renal function, cardiovascular status, etc.), environmental factors (e.g. cigarette smoking, drug-drug interactions, diet, occupationally hazardous chemicals, etc.), and (still largely unappreciated) possible contributions from each patient’s microbiome (gut bacteria, which actually comprises ~90% of all the DNA in us).
This article just appeared today on Medscape and is worthwhile sharing immediately for two reasons. First, fluoroquinolones have become a very popular choice of antibiotic for all kinds of infections. Second, the (dose-INDEPENDENT) ADRs of fluoroquinolones are now realized to be, in some cases, extremely serious –– although the percentage of patients in whom such drug toxicity occurs, is still being calculated.
Thinking of a Fluoroquinolone? Think Again
Sarah Kabbani, MD, MSc
July 16, 2016
Medscape Editor’s Note: Since this commentary was prepared, the US Food and Drug Administration (FDA) has strengthened its black box warning for fluoroquinolones to require a separate warning about the drug’s potential mental side effects (disturbances in attention, disorientation, agitation, nervousness, memory impairment, and delirium), and to add a warning about the risk for coma with hypoglycemia. They reiterate their position that because the risk for serious side effects generally outweighs the benefits –– for patients with acute bacterial sinusitis, acute bacterial exacerbation of chronic bronchitis, and uncomplicated urinary tract infections –– fluoroquinolones should be reserved for use in patients with these conditions who have no alternative treatment options.
Hello. I am Sarah Kabbani, a medical officer with the Division of Healthcare Quality Promotion at the Centers for Disease Control and Prevention. Over the next few minutes, I will provide you with important information on fluoroquinolone-prescribing-and-use data, and why appropriate fluoroquinolone prescribing is an important patient safety issue.
Fluoroquinolones are the third most commonly prescribed outpatient antibiotic class in the United States in adults, with an estimated 115 prescriptions per 1000 persons annually. In 2016, the FDA issued a black box warning (its strongest warning) to stress serious and disabling adverse events associated with systemic fluoroquinolone use, including damage to tendons, muscles, joints, nerves, and the central nervous system.
A new study published in Clinical Infectious Diseases reports that fluoroquinolones are commonly prescribed for conditions when antibiotics are not needed at all, or when fluoroquinolones are not the recommended first-line therapy. In medical offices and emergency departments, about 5% of all fluoroquinolones prescribed for adults are completely unnecessary, and about 20% of all fluoroquinolone prescriptions do not adhere to recommendations about the use of fluoroquinolones as a first-line therapy.
Fluoroquinolones are not recommended for such conditions as uncomplicated urinary tract infections and respiratory conditions, including viral upper respiratory tract infections, acute sinusitis, and acute bronchitis. According to another study, published in JAMA Internal Medicine, only 52% of patients received the recommended first-line antibiotic therapy for three common infections — otitis media, sinusitis, and pharyngitis.
CDC recognizes that the majority of healthcare providers are familiar with antibiotic prescribing guidelines, but many providers admit that they or their colleagues often choose an antibiotic that is not the recommended first-line therapy. Specifically, fluoroquinolones, with their well-documented efficacy, a broad spectrum of activity covering many common pathogens, and favorable pharmacokinetics, are perceived to be safer than other antibiotics, despite the serious adverse events associated with systemic fluoroquinolone use. These characteristics of fluoroquinolones may have led to overprescribing. Additionally, healthcare providers often cite patient satisfaction as a reason for prescribing an antibiotic when no antibiotic is recommended.
Improving antibiotic prescribing is important for preventing serious adverse events and potentially life-threatening Clostridium difficile infections. Based on the FDA’s warning, fluoroquinolones should be used only in patients with acute bacterial sinusitis, acute bacterial exacerbation of chronic bronchitis, or uncomplicated urinary tract infections when no other treatment options are available. It’s important to follow clinical guidelines when prescribing any antibiotic due to the serious potential adverse events.
Prescribing the right antibiotic, at the right dose, for the right duration, and at the right time helps optimize patient care and fight antibiotic resistance. CDC encourages healthcare providers, health systems, and regulators to view appropriate antibiotic prescribing as an important patient safety issue. For more information on antibiotic prescribing and use, please visit CDC’s Antibiotic Prescribing and Use.