April pearls – Penicillin Allergy, Testosterone Therapy and The Elbow Sign in Sleep Apnea

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April 11, 2014

Penicillin – Real allergy or not?  Ten percent of the US population reports having an allergy to penicillin. It turns out that when they are tested, less than a tenth of those people were truly allergic. According to a recent study this is an important point to clarify. Those with a stated allergy to penicillin were more likely to be given broader spectrum antibiotics. In turn, they had slightly longer hospital stays (on average by 0.6 days), and ended up with more resistant infections, including diarrhea due to Clostridium difficile (C. diff) and methicillin resistant staph infections (MRSA).

To avoid further problems around this issue, try to find out the details of the reaction – could the reaction have been to another medication given at the same time? I find that often it’s a relative who has had a reaction, and a parent tells the patient to avoid it, ‘just in case’. It’s not practical to try to test 10% of the population to verify a penicillin allergy. However, if there is an unclear history and the person is likely to receive frequent antibiotics, it is worth having an allergist skin test them. If there is no skin reaction, they can be given an oral challenge by an experienced allergist in a safe office environment. Not all allergists do this particular test, so it’s worth calling ahead to find out. There is some risk to the testing, but as noted above, there is some risk associated with unnecessarily believing you are penicillin-allergic.

Macy E and Contreras R. J Allergy Clin Immunol 2014 Mar. Solensky R. J Allergy Clin Immunol 2014 Mar. – See more at: http://www.jwatch.org/na33965/2014/03/27/penicillin-allergy-associated-with-longer-hospital-stays?query=topic_allergy#sthash.l5mDATjO.dpuf

On the increased use of testosterone replacement:  Over the past decade, prescriptions for testosterone therapy (TT) have quadrupled in the US. This is worth examining in view of numerous recent articles reporting an increased risk of heart disease in those using it.  In men under 65 with no history of heart disease, there was no significant increase in risk. But in the study group, 10% of those under 65 did have some cardiac history, and in that subgroup, there was a 2-3 fold increased risk of heart attacks. The over-65 population was at double the usual risk of heart attacks in the 90 days after starting TT. Interestingly, there was no increased risk in those taking sildenafil or tadalafil (Viagra or Cialis), which may be due to the rule that this class of medications (PDE5I) can not be prescribed to anyone taking nitrates, a medication for active heart disease. Not surprisingly, not as much risk is found in those studies funded by pharmaceutical companies.

The risk of heart attacks is likely due to the tendency of TT to increase blood pressure, clotting and red cell count. It also lowers HDL (the good lipid) which should be higher to protect the heart.

The current study of prescribing practices in the US and the UK shows that it is prescribed without proper testing at times. 5-10% of US men, but virtually no UK men, had NORMAL testosterone levels when starting TT; in some it was started for a complaint of fatigue. In both of the countries, half of the men starting TT did not have levels checked in the preceding 6 months. Heavy pharmaceutical company marketing, including direct-to-consumer ads, have contributed to inappropriate, and possibly risky, prescribing in light of the numerous reports suggesting an increased risk of heart attacks. Studies in larger and more diverse groups will need to be done so TT could be prescribed only to those in whom the benefits outweigh the risks of therapy.

Layton JB et al. Testosterone lab testing and initiation in the UK and the US, 2000-2011. J Clin Endocrinol Metab 2014 Mar; 99:835.

Have you been awakened by an elbow in your side?   Snoring is not just a noisy nuisance, it can be a sign of obstructive sleep apnea (OSA) that can lead to other health issues. OSA is a common condition in which a person stops breathing more than 5 times per hour, usually without being aware of it. In more severe situations, this may happen 30 or more times per hour.

This study evaluates the ‘elbow sign’ as a predictor of the diagnosis. It proposed a 2 question screening process: Does your bed partner ever poke or elbow you because you are snoring? And do they poke you because you stop breathing? In a group likely to have OSA, like obese men, age over 50 and BMI over 31, the ‘elbow sign’ makes it highly likely that the person has sleep apnea. The author proposes using this test as an alternative to a sleep study, for which the waiting time in his native Canada is 9 months, to go directly to treatment. In the US, the studies are much more readily available, with some home-based alternatives, but are expensive. Newer treatment machines (auto-titrating CPAP) can adjust to the proper pressure and avoid the cost of the initial test. More importantly having such a simple screening questionnaire can start the dialogue about this diagnosis.

These frequent episodes of decreased breathing and momentary awakenings often lead to decreased oxygen delivery to the brain and heart. They are associated with daytime fatigue, motor vehicle accidents, decreased productivity at work, high blood pressure, and increased risk for heart disease, irregular heart rhythms and stroke. There are many questionnaires that try to predict who might have sleep apnea and who should go for an overnight test in a sleep lab, but they are quite cumbersome. Perhaps the elbow sign can be a quick alternative.

Fenton et al. The Utility of the Elbow Sign in the Diagnosis of OSA Chest 2014; 145(3):518-524.