house dust mite allergen extract contains allergen extract from common household dust mites. Dust mite allergies can trigger breathing problems or skin reactions.

House dust mite allergen extract is used to help your body develop an immunity to dust mites, and reduce symptoms such as sneezing, itching, and eye redness. This medicine is for use in adults up to age 65.

House dust mite allergen extract may also be used for purposes not listed in this medication guide.

You should not use house dust mite allergen extract if you have uncontrolled asthma, or if you have a history of allergic reaction to an allergen or pollen extract medicine, or an allergic reaction that affected your esophagus.

You may not be able to use house dust mite allergen extract if you have breathing problems, heart disease, or high blood pressure, or if you use certain medicines.

House dust mite allergen extract may cause a severe allergic reaction. Your doctor will give you the first dose and watch you closely to make sure you do not have a reaction.

Your doctor may perform an allergy skin test or blood test to make sure you are allergic to the specific allergen contained in house dust mite allergen extract.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Your doctor will give you the first dose and watch you closely for at least 30 minutes, to make sure you do not have an allergic reaction.

House dust mite allergen extract is a sublingual tablet that dissolves under your tongue. Do not chew this tablet or swallow it whole.

To take the sublingual tablet:

• Remove a tablet from the package only when you are ready to take the medicine.

• Use dry hands to remove the tablet and place it in your mouth.

• Place the sublingual tablet under your tongue and allow it to dissolve completely.

• Do not swallow for at least 1 minute. Do not eat or drink anything for at least 5 minutes.

Wash your hands after handling the sublingual tablet.

A child using house dust mite allergen extract should be supervised by an adult while taking this medicine.

Your doctor may also prescribe epinephrine (Epi-Pen) to keep with you in case you ever have an allergic reaction to house dust mite allergen extract.

If you need oral surgery or dental work, or if you have a mouth injury or infection, you may need to stop using this medicine until your mouth heals. Tell your doctor if the sublingual tablets cause any mouth irritation.

Store tablets in the blister pack at room temperature, away from moisture and heat.

You should not use house dust mite allergen extract if you've had an allergic reaction to similar allergen or pollen extract medicines, or if:

• you have severe or uncontrolled asthma;

• you have had an allergic reaction that affected your esophagus (the tube that connects your mouth and stomach) and caused heartburn or trouble swallowing; or

• you are younger than 18 years or older than 65 years.

Tell your doctor if you have ever had:

• mouth sores, swollen gums, or other wounds or irritations inside your mouth;

• breathing problems;

• heart disease;

• uncontrolled high blood pressure;

• if you take an antidepressant or migraine headache medicine; or

• if you take medicine to treat heart problems, high blood pressure, or a prostate disorder.

It is not known whether this medicine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

It may not be safe to breast-feed while using this medicine. Ask your doctor about any risk.

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Ask your doctor before starting any new medicine or treatments, including allergy shots.

House dust mite allergen extract may cause a severe allergic reaction. Stop taking the medicine and get emergency medical help if you have any of these signs of an allergic reaction:

• severe dizziness or a light-headed feeling (like you might pass out);

• fast heart rate;

• stomach pain, vomiting, diarrhea;

• hives, itching, flushing (warmth, redness, or tingly feeling);

• cough, chest tightness, wheezing, trouble breathing; or

• swelling of your face, lips, tongue, or throat.

If you stop taking house dust mite allergen extract after having an allergic reaction, do not start taking the medicine again without your doctor's advice.

House dust mite allergen extract may cause serious side effects. Call your doctor at once if you have:

• severe mouth or throat irritation;

• breathing problems; or

• choking feeling, chest pain, trouble swallowing.

Common side effects of house dust mite allergen extract may include:

• pain, swelling, itching or sores in your mouth or on your tongue;

• throat irritation;

• altered sense of taste;

• cough, sore throat, sinus pain;

• nausea; or

• itching in your ears.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Other drugs may affect house dust mite allergen extract, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.