Sublingual immunotherapy (SLIT)

Sublingual immunotherapy (SLIT) is an alternative form of allergy immunotherapy which involves administering allergens in a liquid or tablet under the tongue. Like subcutaneous immunotherapy (SCIT) the amount of allergen administered is gradually increased, until there is a maintenance phase, then completion of treatment.(1) “SLIT is similar to SCIT in terms of effectiveness of controlling allergy symptoms, and both have been shown to provide long term improvement even after the treatment has ended.”(1)

“SLIT is similar to SCIT in terms of effectiveness of controlling allergy symptoms, and both have been shown to provide long term improvement even after the treatment has ended.”(1)

With SLIT, the immune system of the gastrointestinal tract tolerates the allergen, in gradually higher doses. When the body then has real world exposure to the allergy source – for example pollen or cat dander – it does not generate symptoms such as congestion and sneezing.(2)

SLIT may be preferred for children who don’t like needles, as well as patients with transportation issues, and patients with high copays (who would be responsible for making a payment at each shot appointment).(3)

Some Contraindications to SLIT

  • Eosinophilic esophagitis
  • Patient’s inability to communicate effectively with physician
  • Pregnancy
  • Cardiovascular disease
  • Patient’s use of a beta-blocker(4)

Use of SLIT in the U.S. has grown steadily in recent years. A 2011 survey of members of the American College of Allergy, Asthma & Immunology found that 11.4% of providers used SLIT, which was up from 5.9% in 2007.(5) A 2018 survey by the same organization received responses from 268 allergists, with 73% reporting they used SLIT in their practices.(4)

The Food and Drug Administration has approved four SLIT tablets. The four tablet formulations approved are two for different kinds of grass pollen, one for short ragweed, and one for dust mites.(1)

The FDA has not approved drops, and therefore SLIT drops are considered an out-of-pocket expense for patients. A study published in the International Forum of Allergy and Rhinology comparing the cost of SCIT AND SLIT concluded: “When loss of productivity and travel expense are added into the cost of SCIT, SLIT might be comparable in cost and more convenient for the patient. Although the lack of insurance coverage for SLIT currently makes it more expensive than SCIT, we have found that the financial gap is much smaller than initially thought, especially when indirect costs and plans with less than 80% coverage or high weekly co-pay are factored into the equation.”(6)

Edge Pharma offers SLIT compounded treatment sets, as well as SLIT metered dropper bottles for providers choosing to compound in-house. In addition, our Xtract Immunotherapy software provides full support for providers offering SLIT. Xtract’s Prescribe and Mix modules aid the formulating and compounding of SLIT in the clinic, and the Outsource functionality makes outsourcing the compounding to Edge effortless.

(1) American Academy of Allergy, Asthma & Immunology, SLIT Treatment For Allergic Rhinitis Nothing to Sneeze About,
(2) More, D. M.D., verywellhealth, What You Need to Know About Sublingual Immunotherapy,
(3) Sapporta, D. M.D., BioMed Research International, Sublingual Immunotherapy: A Useful Tool for the Allergist in Private Practice,
(4) Boyles, S. Allergy & Immunology, SLIT a Hit Among Allergists,
(5) Cox, L. M.D. The Journal of Allergy and Clinical Immunology, Sublingual Immunotherapy: Historical Perspective and Practical Guidance,
(6) Seiberling, K. M.D., Heibert, J., et. all., Medical Management Design, Cost of Allergy Immunotherapy: Sublingual vs. Subcutaneous Administration,