Oralair, Grastek, and Ragwitek for Grass and Ragweed Allergies

Sublingual immunotherapy (SLIT) is a form of immunotherapy that is used for treating certain allergies. It is a method of preventing an immune reaction to an allergen by placing the allergen extract, in the form of liquid drops or a dissolvable tablet, under the tongue.

SLIT is an alternative to allergy shots and it has been used for many years in Europe and other areas around the world. SLIT was approved by the U.S. Food and Drug Administration (FDA) in 2014, Several different sublingual allergens are used to prevent symptoms of allergic rhinitis and allergic conjunctivitis.

Oralair and Grastek were approved for the treatment of grass pollen allergy, and Ragwitek was approved for the treatment of ragweed pollen allergy.  Odactra is a sublingual immunotherapy tablet approved to treat dust mite allergy.

Man taking a walk in the fall
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Oralair, Grastek, and Ragwitek are all taken in the same fashion. They are taken once daily, starting several months prior to their desired effect, and continuing until the end of the pollen season.

Your first dose should be taken under medical supervision and you can expect to be monitored for at least 30 minutes afterward.

To take each dose:

  • Place the tablet under your tongue to allow it to dissolve
  • Don't swallow for at least one minute afterward
  • Don't eat or drink for at least five minutes after that

It takes time to obtain benefit from SLIT—typically several weeks to several months. SLIT works by changing the way your immune system reacts to allergens over time to prevent allergy symptoms.

SLIT does not treat the immediate symptoms of allergies. For the treatment of your nasal allergy symptoms, your doctor will prescribe medicine, such as an oral antihistamine or nasal antihistamine spray.

You might also be prescribed an epinephrine auto-injector. You should have this available during your allergy season and learn how to use it in the event of anaphylaxis. If you experience acute, life-threatening allergy symptoms, you would need to use epinephrine—antihistamines don't act quickly enough and are not strong enough to reverse life threatening allergy symptoms.

Oralair for Grass Pollen-Induced Allergic Rhinitis

Oralair is a mixture of five different grass allergens in a single sublingual tablet. It is indicated for the treatment of grass pollen allergic rhinitis and allergic conjunctivitis in people five to 65 years of age.

The manufacturer recommends that Oralair be started 4 months prior to the grass pollen season and taken every day until the grass pollen season is over. Grass season often starts in April or May.

Research trials showed that Oralair decreased allergy symptoms and reduced the need to use allergy medication by an average of 30-40% when compared to placebo.

Common side effects included throat irritation and swelling, mouth and ear itching, and coughing.

Grastek for Grass Pollen-Induced Allergic Rhinitis

Grastek is timothy grass allergen in a sublingual tablet. It is indicated for the treatment of grass pollen allergic rhinitis and allergic conjunctivitis in people five to 65 years of age.

The manufacturer recommends that Grastek be started at least 12 weeks prior to the grass pollen season and taken every day until the grass pollen season is over. Grastek can be taken continuously for three consecutive years.

Studies showed that Grastek reduces allergy symptoms and allergy medication use by an average of 20-35% when compared to placebo.

Ragwitek for Ragweed Pollen-Induced Allergic Rhinitis

Ragwitek is ragweed allergen in a sublingual tablet. It is indicated for the treatment of ragweed pollen allergic rhinitis and allergic conjunctivitis in people 18 to 65 years of age.

The manufacturer recommends that Ragwitek be started at least 12 weeks prior to the ragweed pollen season and taken every day until the ragweed pollen season is over. Ragweed season generally starts in August, depending on the geographic location.

Studies showed that allergy symptoms and allergy medication use decreased in people allergic to ragweed when compared to placebo.

Common side effects included throat irritation and swelling, mouth and ear itching, tongue itching, and numbness in the mouth.

Beyond those allergens, which are standardized in their major allergen content, it is unlikely that other allergens will become available in a sublingual tablet form. However, sometimes allergists offer sublingual drops, which are currently not FDA approved, to be used under the tongue. Many are approved to be injected as an allergy shot to treat allergies caused by a variety of other pollens, mold spores, and animal dander.

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  2. Pleskovic N, Bartholow A, Gentile DA, Skoner DP. The Future of Sublingual Immunotherapy in the United StatesCurrent Allergy and Asthma Reports. 2015;15(8). doi:10.1007/s11882-015-0545-x

  3. Food and Drug Administration. Odactra label. March 2020.

  4. Köberlein J, Mösges R. Oralair®: a causal treatment for grass pollen-induced allergic rhinoconjunctivitisImmunotherapy. 2013;5(1):13-21. doi:10.2217/imt.12.147

  5. Scaparrotta A, Attanasi M, Petrosino MI, Di Filippo P, Di Pillo S, Chiarelli F. Critical appraisal of Timothy grass pollen extract GRAZAX in the management of allergic rhinitisDrug Des Devel Ther. 2015;9:5897–5909. Published 2015 Nov 3. doi:10.2147/DDDT.S70432

  6. Nelson HS. Ragweed allergy immunotherapy tablet MK-3641 (Ragwitek®) for the treatment of allergic rhinitisExpert Review of Clinical Immunology. 2018;14(12):1003-1011. doi:10.1080/1744666x.2018.1538788

Additional Reading
  • Grastek Package Insert

  • Oralair Package Insert

  • Ragwitek Package Insert