house dust mite immunotherapy

House dust mite (HDM) immunotherapy is a treatment approved for house dust mite-induced allergic rhinitis, with or without conjunctivitis, in patients 12 to 65 years of age. HDM immunotherapy is a tablet that contains house dust mite allergen extracts from two types of house dust mites Dermatophagoides farinae and Dermatophagoides pteronyssinus. HDM immunotherapy is used in patients who test positive to skin testing with HDM allergen extracts or for IgE antibodies to Dermatophagoides farinae or Dermatophagoides pteronyssinus.

Allergic reactions are caused by the presence of allergen-specific immunoglobulin E (IgE) antibodies bound to immune cells, basophils and mast cells. IgE antibodies sensitize these immune cells, which release histamine and other inflammatory substances when exposed to these allergens, producing allergic reactions. HDM immunotherapy works by modulating the immune response to house dust mite allergens.

The complete mechanism of how HDM immunotherapy improves allergic symptoms is not clear. HDM immunotherapy may work by inducing a switch from T helper 2 cell response (Th2) to T helper 1 cell (Th1) response. Th2 response promotes inflammation while Th1 response produces anti-inflammatory activity. Switching of Th2 response to Th1 response results in several anti-inflammatory processes including:

• Decreased secretion of pro-inflammatory proteins (cytokines) interleukin-4 (IL-4) and interleukin-5 (IL-5)
• Increase in secretion of anti-inflammatory cytokine IL-10
• Production of IgG blocking antibodies that bind to the allergen, preventing IgE antibodies from allergen binding and producing an allergic reaction
• Proliferation of regulatory T-cells and cytokines that suppress inflammation
• Decrease in mast cells and eosinophils, which produce an allergic response

• Do not use HDM immunotherapy in patients with:
  • Hypersensitivity to any component in the formulation
  • History of severe systemic allergic reaction
  • Severe unstable or uncontrolled asthma
  • History of eosinophilic esophagitis
  • History of severe local reaction to any sublingual allergen immunotherapy
• HDM immunotherapy can cause severe and sometimes life-threatening local and systemic reactions such as throat and voice box swelling that can compromise breathing, and anaphylaxis. Severe allergic reactions may require prompt treatment.
  • Administer the initial dose of HDM immunotherapy under the supervision of an allergy disease specialist, with readily available facilities for managing severe allergic reactions. Monitor patients for at least 30 minutes following initial dose.
  • Instruct patients on the emergency use of auto-injectable epinephrine for severe allergic reactions, and advise them to discontinue HDM immunotherapy immediately and seek medical care as soon as possible after administration of epinephrine.
• Concurrent use of HDM immunotherapy with other allergen immunotherapies can increase the risk of adverse reactions.
• HDM immunotherapy may not be suitable for patients with certain medical conditions that may compromise the ability to survive a severe allergic reaction or increase the risk of adverse reactions with the use of epinephrine, such as:
  • Significantly impaired lung function
  • Severe mast cell disorder
  • Cardiovascular conditions including:
    • Irregular heart rhythm (arrhythmia)
    • Unstable angina
    • Recent heart attack (myocardial infarction)
    • Uncontrolled hypertension
    • Taking medications that can interfere with epinephrine
• HDM immunotherapy can cause local reactions in the mouth and throat which can compromise the upper airway. Consider discontinuing HDM immunotherapy in patients with persistent adverse reactions in the mouth and throat.
• HDM immunotherapy can cause allergic inflammation of the esophagus (eosinophilic esophagitis). Discontinue treatment and evaluate for eosinophilic esophagitis in patients with severe or persistent symptoms such as chest pain and difficulty swallowing.
• Withhold treatment in patients with acute asthma exacerbation. Consider discontinuing the treatment in patients who experience recurrent asthma exacerbations.
• In patients with oral wounds, such as those following dental surgery or tooth extraction, and oral inflammations such as oral lichen planus, thrush or mouth ulcers, interrupt HDM immunotherapy treatment until the oral cavity is completely healed.

Common side effects of house dust mite immunotherapy include:

• Throat irritation/tickle
• Throat swelling
• Itching (pruritus) in the ear 
• Itching in the mouth
• Swelling of the mouth
• Swelling of the uvula
• Swelling of the lips
• Swelling of the tongue
• Tongue pain
• Ulcer or sore on the tongue
• Ulcer or sore in the mouth
• Nausea
• Stomach pain
• Diarrhea
• Vomiting
• Taste alteration (dysgeusia)
• Abnormal prickling, tingling or burning sensations in the mouth (oral paresthesia)
• Oral pain
• Tongue itching
• Oral inflammation (stomatitis)

Less common side effects of house dust mite immunotherapy include:

• Canker sore (aphthous ulcer)
• Redness of the mouth (oral erythema)
• Tongue discomfort
• Lip pruritus
• Salivary gland enlargement
• Swallowing difficulty (dysphagia)
• Allergic inflammation of esophagus (eosinophilic esophagitis)
• Indigestion (dyspepsia)
• Gastroesophageal reflux disease (GERD)
• Ear pain
• Ear discomfort
• Eye pruritus
• Eye swelling
• Acute sinus inflammation (sinusitis)
• Mouth and throat pain (oropharyngeal pain)
• Voice box swelling (laryngeal edema)
• Nasal discharge (rhinorrhea)
• Enlargement of tonsils (tonsillar hypertrophy)
• Throat tightness
• Dry throat
• Sneezing
• Cough
• Upper respiratory tract infection
• Chest discomfort
• Chest pain
• Non-cardiac chest pain
• Hives (urticaria)
• Skin itching
• Flushing
• Skin redness (erythema)
• Joint pain (arthralgia)
• Neck pain
• Severe systemic allergic reaction (anaphylaxis)

Call your doctor immediately if you experience any of the following symptoms or serious side effects while using this drug:

• Serious heart symptoms include fast or pounding heartbeats, fluttering in your chest, shortness of breath, and sudden dizziness;
• Severe headache, confusion, slurred speech, severe weakness, vomiting, loss of coordination, feeling unsteady;
• Severe nervous system reaction with very stiff muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, and feeling like you might pass out; or
• Serious eye symptoms include blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights.

This is not a complete list of all side effects or adverse reactions that may occur from the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may also report side effects or health problems to the FDA at 1-800-FDA-1088

Tablet, sublingual (SL)

• 12 SQ-HDM
• SQ is a method of standardization of biological potency, major allergen content, and complexity of allergen extract; HDM is abbreviation for house dust mite

Adult and Pediatric

Allergic Rhinitis

• Sublingual allergy immunotherapy (SLIT) tablet indicated for dust mite-induced allergic rhinitis with or without conjunctivitis, confirmed by in vitro testing for IgE antibodies to Dermatophagoides farinae or Dermatophagoides pteronyssinus house dust mites, or skin testing to licensed house dust mite allergen extracts, in people aged 12-65 years
• 1 tablet SL once daily
• Safety and efficacy not established in children below 12 years and adults above 65 years

Overdose

Overdose of house dust mite immunotherapy may cause systemic allergic reactions or severe local allergic reactions. Symptoms of hypersensitivity reactions include swelling under the skin and in mucous tissue (angioedema), difficulty breathing, changes in voice and feeling of fullness in the throat. Overdose is treated with supportive care as deemed necessary, including administration of epinephrine.

Inform your doctor of all medications you are currently taking, who can advise you on any possible drug interactions. Never begin taking, suddenly discontinue, or change the dosage of any medication without your doctor’s recommendation.

• House dust mite immunotherapy has no listed severe, serious, moderate or mild interactions with other drugs.

The drug interactions listed above are not all of the possible interactions or adverse effects. For more information on drug interactions, visit the RxList Drug Interaction Checker.

It is important to always tell your doctor, pharmacist, or health care provider of all prescription and over-the-counter medications you use, as well as the dosage for each, and keep a list of the information. Check with your doctor or health care provider if you have any questions about the medication.

• Animal reproductive studies did not reveal drug-related adverse outcomes with the use of house dust mite immunotherapy during pregnancy. Available data on house dust mite immunotherapy use in pregnant women is inadequate to determine drug-associated risks to the fetus.
• In general, allergy immunotherapy may be continued if a patient tolerating the treatment well becomes pregnant during treatment, however, allergy immunotherapy is not usually initiated in a pregnant woman.
• There is no information on the presence of house dust mite allergen extract in breastmilk, or its effects on milk production and the breastfed infant. Decision to breastfeed should be based on the mother’s clinical need for house dust mite immunotherapy, benefits of breastfeeding to the infant, and potential risk to the infant from exposure to the drug or underlying maternal condition.

• Take house dust mite immunotherapy exactly as prescribed.
• Discontinue house dust mite immunotherapy and contact your physician immediately if you experience severe allergic reactions. Symptoms may include rash, hives, itching, flushing, vomiting, diarrhea, abdominal pain, chest discomfort, cough, bronchospasm, shortness of breath, rapid heart rate, low blood pressure, dizziness and fainting.
• Follow instructions for use of epinephrine for immediate treatment of severe hypersensitivity reactions and seek medical help as early as possible.
• Report to your physician if you experience severe and persistent adverse reactions in your mouth, throat or esophagus.
• Discontinue house dust mite immunotherapy and seek medical help immediately if you have asthma and have difficulty breathing or are unable to control your asthma.
• Store house dust mite allergen extract safely out of reach of children.
• In case of overdose, seek immediate medical help or contact Poison Control.