SAFETY AND TOLERABILITY OF SUBLINGUAL IMMUNOTHERAPY IN CLINICAL TRIALS AND REAL LIFE

FCAAIA Notes: We have posted several articles about the safety and efficacy of sublingual immunotherapy (SLIT) for aeroallergen sensitivity.  In recent weeks, the FDA has approved sublingual tablets for grass and ragweed immunotherapy, affirming older European data proving that these treatments are better than placebo.  The total monthly dose is dramatically higher than that given by injection. In order to achieve these doses, the tablet must be placed under the tongue everyday and be allowed to melt for 10 seconds. There are a few studies comparing SLIT with conventional subcutaneous allergen immunotherapy (allergy shots, SCIT).  Those studies show that SCIT is more effective than SLIT.

Of great importance, SLIT tablets are not available in the United States for other allergens. European studies of SLIT using multiple allergens show that it is less effective than for just single allergens.  Perhaps that is because of the inconvenience of delivery.  Suppose you are allergic to 6 trees, 6 molds, cat, dog, dust mites, grass, and 6 weeds (total of 22 allergens).  If you had to put each of 22 tablets under your tongue for 10 seconds once a day, it would take 4 minutes to take your doses every day.  It is unlikely anybody would do that!

There are many practitioners who encourage their patients to use “allergy drops.” That method has never been shown to be more effective than placebo.  The Latin phrase “Argumentum ad populum” means “Argument to the people”. The phrase falsely concludes that if many people believe something to be so, it must be. However, popular belief dose not make something true. Elvis is no longer alive. Nonetheless, for patients allergic to just grass and/or ragweed who also have serious enough symptoms to require immunotherapy, SLIT is an option to consider.

(Source: http://www.medscape.com/viewarticle/813722_1   January 7, 2014.  For Medscape articles: User name: FCAAIA, Password: Allergies)

Abstract

Purpose of review Sublingual immunotherapy (SLIT) is effective in allergic rhinitis and asthma. Apart from its efficacy, safety is crucial as this treatment is usually self-administered at home. Tolerability also plays a pivotal role, as mild local reactions, although not life-threatening, may represent a risk for treatment withdrawal and can therefore negatively affect clinical outcomes. The present study addresses this issue by reviewing double-blind, placebo-controlled, randomized trials and real-life studies.

Recent findings The number of life-threatening SLIT-related reactions is negligible. SLIT-related adverse events are not always consistently reported nor uniformly classified in published studies. However, systemic reactions are rare and side effects mostly consist of mild, self-limiting local reactions. No treatment-related risk factors for adverse events have been clearly defined, as far as type of allergen, dose or schedule.

Summary SLIT provides an optimal safety profile both in children and in adults. Apart from life-threatening reactions, the lack of standardization of adverse events reporting may account for the wide variability of the prevalence of side effects in clinical trials and in real-life setting. It can lead to a possible underestimation of adverse events, concerning, in particular, local reactions. Since poor tolerability may affect adherence and cause treatment discontinuation, adopting shared strategies in order to recognize, grade and manage adverse events is mandatory.

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