Arefa MD's Morning Report: Penicillin Allergy, Overprescribing Levothyroxine, Final USPSTF Statin Recommendations

Arefa Cassoobhoy, MD, MPH


December 02, 2016

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Hello. I'm Dr Arefa Cassoobhoy, a practicing internist and a medical editor for Medscape and WebMD. Welcome to our weekly brief on recent medical news and findings.

Penicillin Allergies: Real or Not?

We first look at penicillin allergies. While about 10% of the US population reports a penicillin allergy, a recent study in the inpatient setting found that only about 1 in 10 of those labeled penicillin allergic were actually allergic. And this incorrect label in the electronic medical record (EMR) is dangerous. It's associated with higher rates of hospitalizations and Clostridium difficile, methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant enterococci (VRE). In the same study, 34% of the patients on antibiotics were switched by their medical team to a more narrow-spectrum penicillin or cephalosporin once their penicillin allergy label was removed.

A recent survey of clinicians found widespread misunderstanding about penicillin allergies. A sizeable number of respondents—42%—did not know that a penicillin allergy can resolve over time. Over 80% of clinicians never or rarely consulted an allergist or immunologist to confirm a reported penicillin allergy.

So if the EMR says that your patient is allergic to penicillin, consider a deeper dive to determine whether the allergy is real. It might avoid unnecessary broad-spectrum antibiotic use in their future.

Overprescribing Levothyroxine

Next, clinicians are being urged to reevaluate their use of levothyroxine in patients with presumed hypothyroidism. There's evidence that the drug is being overprescribed. In fact, it's the most prescribed drug in the United States, and prescriptions have risen significantly in recent years.

Yet, an editorial by authors at the Mayo Clinic explains that there's been no real increase in the incidence of hypothyroidism. They blame the rise on earlier recommendations to treat subclinical increases in thyroid-stimulating hormone (TSH) levels even in the absence of symptoms.

They suggest that prescribing levothyroxine to treat subclinical hypothyroidism should be considered on a patient-by-patient basis—and then only after at least two elevated TSH levels, measured 3-6 months apart. Patients with nonspecific symptoms and normal thyroid function tests do not benefit from therapy.

USPSTF: Final Recommendations for Use of Statins in Primary Prevention

Finally, the US Preventive Services Task Force has finalized its recommendations for prescribing statins to help prevent cardiovascular disease.

The key points are:

  • Low- to moderate-dose statins should be considered for adults aged 40 -75 years who do not have a history of cardiovascular disease but who have one or more risk factors, such as dyslipidemia, diabetes, hypertension, or smoking.

  • Consider statins for those who have a 10% or higher risk for a heart attack or stroke based on their 10-year American College of Cardiology/American Heart Association cardiovascular risk equations.

  • Some patients with a 7.5%-10% risk for an event in the next 10 years may benefit.

The Task Force also concludes that there's not enough evidence to recommend starting statins in adults 76 years or older. It should also be noted that these guidelines are not for patients who are extremely high-risk, such as those with familial hypercholesterolemia or those with LDL levels over 190.

For Medscape and WebMD, I'm Dr Arefa Cassoobhoy.

Follow Dr Cassoobhoy on Twitter at @ArefaMD


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