Ragweed pollen allergy: SLIT safe and effective alternative to injections

Medication Delivered Under the Tongue May Be Alternative to Allergy Shots

An oral allergy treatment administered in drops under the tongue is a safe and effective alternative to injections for adults who are allergic to ragweed pollen, according to a study published today in the Journal of Allergy and Clinical Immunology by allergic disease specialist at Allegheny General Hospital.  

Widely used in Europe, but not yet approved by the U.S. Food and Drug Administration, sublingual allergen immunotherapy (SLIT) can be a more convenient and tolerable treatment approach that leads to greater patient compliance, said David Skoner, MD, director of AGH's Division of Allergy, Asthma and Immunology and a co-lead investigator in the study.  

"The study's findings mark a step forward in gaining approval for sublingual administration of allergy medication," said Dr. Skoner, "We believe a large number of patients would greatly benefit from having access to this new oral treatment to ease their symptoms."

"The sublingual method so far has been safe, and the adherence rate should be better because no injections are involved and the medication is administered at home," said co-investigator Deborah Gentile, MD, Director of Research in AGH's Division of Allergy, Asthma and Immunology.

The AGH study, "Sublingual Immunotherapy in Patients with Allergic Rhinoconjunctivitis Caused by Ragweed Pollen," involved 115 patients in Pittsburgh, Madison, Wisc., Iowa City and Evansville, Ind. They were randomly assigned to a medium or high dose of standardized glycerinated short ragweed pollen extract or to a placebo.  Participants kept diaries to monitor their symptoms over the course of 17 weeks during the ragweed pollen season.

The frequency of daily symptoms, as well as the need for additional medication to treat symptoms, both dropped significantly for those taking the high-dose medication, versus those taking a placebo. The frequency of adverse events was similar between the placebo and treatment groups.

The researchers concluded that SLIT was safe and can reduce symptoms in ragweed-sensitive patients, though more trials are needed to definitively establish the method's efficacy.

Shortcomings of previous trials with the sublingual method included small patient populations, high withdrawals and short treatment duration. Questions remaining on SLIT include treatment schedules, optimal doses and cost-effectiveness.