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House dust mite allergen extract (By mouth)

Dermatophagoides Farinae Extract, Dermatophagoides Pteronyssinus Extract

Treats hay fever caused by house dust mites.

Brand Name(s):


There may be other brand names for this medicine.

When This Medicine Should Not Be Used:

This medicine is not right for everyone. Do not use it if you have a severe and poorly controlled asthma, or a history of eosinophilic esophagitis or allergic reaction (including allergic reaction caused by taking other allergen immunotherapy).

How to Use This Medicine:


  • Your doctor will tell you how much medicine to use. Do not use more than directed.
  • You must take your first dose of this medicine in a doctor's clinic or hospital. This is done to observe you for at least 30 minutes for possible allergic reactions. If the first dose is well tolerated, then you can take this medicine at home.
  • To use: Take the tablet out from the blister with dry hands. Place the tablet under your tongue where it will dissolve within 10 seconds. Avoid swallowing for at least 1 minute.
  • Wash your hands after handling the tablet.
  • Do not eat or drink any liquid for 5 minutes after taking the medicine.
  • Your doctor will give you a medicine called epinephrine. This is to be used to relieve a severe allergic reaction. Your doctor will give you instructions on how to use it properly.
  • This medicine should come with a Medication Guide. Ask your pharmacist for a copy if you do not have one.
  • Missed dose: Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.
  • Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep the medicine in the original package until use to protect from moisture.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • Some medicines can affect how house dust mite allergen extract works. Tell your doctor if you are using any of the following:
    • Chlorpheniramine, digoxin, diphenhydramine, or levothyroxine
    • Blood pressure medicine
    • Diuretic (water pill)
    • Ergot medicine
    • MAO inhibitor
    • Medicine to treat depression

Warnings While Using This Medicine:

  • Tell your doctor if you are pregnant or breastfeeding, or if you have heart disease, heart rhythm problems, high blood pressure, a recent heart attack, or lung disease. Tell your doctor if you have any sores in your mouth or throat, oral thrush, or wounds in your mouth after dental surgery.
  • Your doctor will check your progress and the effects of this medicine at regular visits. Keep all appointments.
  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
  • Chest pain, fast or uneven heartbeat
  • Lightheadedness, dizziness, fainting
  • Sores or ulcers in the mouth or throat
  • Trouble breathing or swallowing

If you notice these less serious side effects, talk with your doctor:

  • Change in taste
  • Diarrhea, nausea, stomach pain

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Last Updated: 5/1/2020

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites.

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