Oral drops may replace shots for allergy and asthma sufferers
Many allergy and asthma sufferers rely on injections to relieve their symptoms. Now, a large new study offers a pleasant article to a needle stick: oral drops. Researchers affiliated with Johns Hopkins University School of Medicine published their findings on March 27 in the Journal of the American Medical Association.
The researchers note that allergic rhinitis, characterized by nasal congestion and sneezing, affects up to 40% of the United States Population. To desensitize allergic individuals, subcutaneous injection immunotherapy (injections just below the skin) or sublingual immunotherapy (tablets placed under the tongue) may be administered.
However, in the US, sublingual immunotherapy is not approved by the Food and Drug Administration (FDA). However, some US physicians use water-based aqueous allergens, off-label for sublingual desensitization. An allergen is a substance that stimulates an immune response. The goal of desensitization therapy is to reduce allergic reactions by administering a very small dose of an allergen.
The objective of the new study was to systematically review the effectiveness and safety of aqueous sublingual immunotherapy for allergic rhinoconjunctivitis and asthma. The researchers accessed the following databases: MEDLINE, EMBASE, LILACS, and the Cochrane Central Register of Controlled Trial. The databases were searched through December 22, 2012. English-language randomized controlled trials were included if they compared sublingual immunotherapy with placebo, pharmacotherapy (medical therapy), or other sublingual immunotherapy regimens and reported clinical outcomes. Excluded were studies of sublingual immunotherapy that are unavailable in the United States and for which a related immunotherapy is unavailable in the United States.
Paired reviewers selected articles and extracted the data. The strength of the evidence for each comparison and outcome was graded based on the risk of bias (scored on allocation, concealment of intervention, incomplete data, sponsor company involvement, and other bias), consistency, magnitude of effect, and the directness of the evidence.
The investigators located 63 clinical studies with 5,131 participants that met the inclusion criteria. The participants' ages ranged from 4 to 74 years. Twenty studies (1,814 patients) enrolled only children. The researchers found that the risk of bias was medium in 43 studies (68%). Eight of 13 studies were found to have strong evidence (greater than 40% improvement) supportive of the improvement of asthma symptoms with sublingual immunotherapy improves asthma symptoms. They also found moderate evidence, which supported that sublingual immunotherapy use decreases rhinitis or rhinoconjunctivitis symptoms; 9 of 36 studies demonstrated greater than 40% improvement. Medication use for asthma and allergies decreased by more than 40% in 16 of 41 studies of sublingual immunotherapy with moderate grade evidence.
Moderate evidence supports that sublingual immunotherapy improves conjunctivitis symptoms (13 studies), combined symptom and medication scores (20 studies), and disease-specific quality of life (8 studies). Local reactions were frequent; however anaphylaxis (a sever, life-threatening allergic reaction) was not reported.
The authors wrote in conclusion: “the overall evidence provides a moderate grade level of evidence to support the effectiveness of sublingual immunotherapy for the treatment of allergic rhinitis and asthma, but high-quality studies are still needed to answer questions regarding optimal dosing strategies. There were limitations in the standardization of adverse events reporting, but no life-threatening adverse events were noted in this review.”
Reference: Journal of the American Medical Association