Standardized Mite

Glycerinated extracts contain:

There are no known absolute contraindications to hyposensitization therapy. See precautions section for pregnancy risks.

      A patient should not be treated with allergens unless a history of symptoms and a positive skin test reaction have been demonstrated. Allergenic extracts should only be administered to patients that show symptoms of allergy or asthma. The physician must determine if the benefits outweigh the risks in using these products for treating these patients.

Patients who are taking non-selective beta blockers may be more reactive to allergens given for testing or treatment and may be unresponsive to the usual doses of epinephrine used to treat allergic reactions.

See WARNINGS at the beginning of the instruction sheet.

Extracts standardized using the Allergy Unit may be more potent than extracts based on weight to volume or PNU methods of expressing potency. Comparative skin tests can be performed to determine the relative potency before initial use of new extracts. DO NOT GIVE ALLERGY INJECTIONS INTRAVENOUSLY. Subcutaneous injections are recommended. Injections may produce large local reactions that may be painful to the patient. DO NOT GIVE FULL STRENGTH INJECTIONS UNTIL THE COMPARATIVE STRENGTH IS DETERMINED. After inserting the needle, but before injecting extract, withdraw the plunger slightly. If blood appears in the syringe, re-insert the needle at another site. Careful selection of dose and injection should prevent most systemic reactions.

GENERAL:

The dosage should be reduced 50-75% from the previous dose when starting a patient on a new lot of Standardized Mite extract from the same manufacturer or from a different manufacturer. When changing from a non-Standardized Mite extract to a Standardized Mite extract the dose should be based upon comparative skin testing or the patient should be treated as though beginning treatment for the first time. 
A separate sterile tuberculin type syringe should be used with each patient to prevent cross contamination of extracts. This will also prevent transmission of disease such as serum hepatitis, AIDS and other infectious diseases. Aseptic technique should always be used when injections of allergenic extracts are administered.

INFORMATION FOR PATIENTS:

Because most serious reactions following the administration of allergenic extracts occur within 20 minutes of the injection, the patient should remain under observation for this period of time. The size of the local reaction should be recorded because increasingly large local reaction may precede a subsequent systemic reaction with increasing dosage. The patient should be instructed to report any unusual reactions to the attention of the physician. In particular, this includes swelling and/or tenderness at the injection site or reactions such as rhinorrhea, sneezing, coughing, wheezing, shortness of breath, nausea, dizziness or faintness.

DRUG INTERACTIONS:

Patients who are taking non-selective beta blockers may be more reactive to allergens given for testing or treatment and may be unresponsive to the usual doses of epinephrine used to treat allergic reactions. Antihistamines can significantly inhibit the immediate skin test reactions. Patients should be free of such medication for at least 48 hours before testing.

CARCINOGENESIS, MUTAGENESIS, IMPAIRMENT OF FERTILITY:

Long term studies with extracts have not been conducted in animals to determine their potential for carcinogenesis, mutagenesis, or impairment of fertility.

PREGNANCY:

Pregnancy Category C. Animal reproduction studies have not been conducted with allergenic extracts. It is also not known whether allergenic extracts can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Allergenic extracts should be given to a pregnant woman only if clearly needed.

Controlled studies of hyposensitization with moderate to high doses of allergenic extracts in pregnant women have failed to demonstrate any risk to the mother or fetus. (6) 

However, with histamines known ability to contract uterine muscles any reaction which would release significant amounts of histamine such as hyposensitization overdose should be avoided. The physician must weigh the benefits of immunotherapy against the risk of anaphylactic reactions that could result in harm to the mother and/or fetus. 

Hyposensitization should be used during pregnancy only if clearly necessary and administered cautiously. If a women is on maintenance dose, the occurrence of pregnancy is not an indication to stop injection therapy.

NURSING MOTHERS:

It is not known if allergenic extracts are excreted in human milk therefore caution should be exercised when extracts are administered in nursing women.

PEDIATRIC USE:

Standardized Mite extract has not been studied in children, so the safety in children has not been established. Doses of allergenic extracts for children are generally the same as those for adults. The extracts may cause some pain or discomfort when injected. The maximum tolerated dose may be less than the adult dose due to the smaller size of the child. Therefore the volume of the dose may need to be adjusted from the adult schedules provided.

DIAGNOSTIC SKIN TESTING:

      Puncture tests performed on 15 highly sensitive patients with 2 separate lots of 10,000 AU/ml Mite Extract (D. farinae) showed a mean sum of diameter wheal of 15.93mm ± 4.92 and a mean sum of diameter erythema of 63.70mm ± 16.46. Puncture tests performed on 10 highly sensitive patients with 10,000 AU/ml Mite Extract (D. pteronyssinus) showed a mean sum of diameter wheal of 17.00mm ± 3.39 and a mean sum of diameter erythema of 84.80mm ± 5.80. Intradermal skin test results in highly sensitive patients is shown below using the same lots as used in the puncture tests above. 

Puncture tests with the mite growth medium as control were negative in 15 patients sensitive to mite.

      These products are used to determine a patient's sensitivity to specific antigens and aid in the diagnosis and treatment of atopic diseases. After a thorough history a decision can be made as to which allergens will be appropriate to use for testing. The recommended procedure is to initially perform puncture tests, then follow with intradermal tests. See recommended dosage below.

FREQUENCY OF ADMINISTRATION: 

The number of skin tests applied at one time will depend on the particular patient and their allergic history. These tests should be performed and observed in 15 to 20 minutes. Additional tests may be applied in sequence. Perform tests on the anterolateral aspect of the upper arm on an area that permits the effective application of a tourniquet proximal to the site of the test. The skin at the site of injection should be disinfected with rubbing alcohol before testing.

Puncture testing: Apply one drop (0.05ml) of extract to the skin. Pierce the drop of extract and skin using a sterile hypodermic needle or vaccinating needle. Maintain the needle perpendicular to the skin surface and rock the needle back and forth to produce a small hole without bleeding. Do not rotate or gouge the needle. Remove needle from skin and wipe excess extract from skin surface.

Scratch testing: Using a scarifier or needle, make a scratch 1/16 inch long on the epidermis penetrating the outer cornified area but being careful not to draw blood. Apply one drop (0.05ml) of allergen to the scratch.

Intradermal testing: Use a separate sterile syringe (tuberculin type equipped with a 27 gauge by 3/8 inch needle with intradermal bevel) for each antigen. The tests are made by injecting 0.02ml of allergen into the epidermis. If the test has been performed properly, the solution should raise a bleb 2 to 3mm in diameter. If the bleb does not appear, the injection was made too deeply.

A negative control consisting of the same solution that the extract was prepared in should be applied to one of the sites in the same manner as the tests being performed. For example, the negative intradermal control should contain 0.5% (v/v) glycerin, if a 100 AU/ml concentration mite is used for intradermal testing. Histamine phosphate should be used as a positive control for evaluation of skin testing. Histamine phosphate is available from other manufacturers. See their directions for use, for recommended dosage and interpretation of results.

A positive reaction usually develops in 15-20 minutes. The positive response is a wheal and flare reaction that is larger than the negative control and judged on the size of the reaction. Scratch or puncture tests may not elicit as large and well defined reaction as the intradermal. (5)

The following system is recommended (8):

IMMUNOTHERAPY:

The following are two methods of injection therapy:

1. Pre-seasonal in which treatment is begun three months before seasonal difficulty begins and brought to maintenance dose by injections four to seven days apart and discontinued after that season ends.
   
2. Perennial treatment is the recommended mode of therapy in which the patient is, by injection therapy, brought up to tolerated maintenance dose and remains at that dose until amelioration of allergic symptoms occurs. Injections may be given at intervals of 4 to 7 days.

Allergenic extracts must be diluted before use. Normally immunotherapy can be started with a 1 AU/ml dilution. If a patient appears to be extremely sensitive, dilutions of the antigen can further be made before injections are started. The following are suggested procedures for making a proper dilution series. Recommended diluents contain 0.9% sodium chloride and 0.4% phenol as a preservative. Allergenic extracts should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.

Perennial treatment may be started using the following dosage and dilution schedule. THIS SCHEDULE IS ONLY ILLUSTRATIVE AND HAS NOT BEEN SUBJECTED TO ADEQUATE OR WELL-CONTROLLED TRIALS TO DETERMINE EITHER ITS SAFETY OR EFFICACY.

Gradually increase the dose as outlined in the schedule. If you give a dose that causes a mild local reaction manifested by warmth or redness, repeat the same dose. If the reaction is severe or systemic (manifested as hives, asthma, or hay fever), drop back a dose in schedule and build again. If a severe local reaction or a systemic reaction is again encountered, this should be considered more than the maximum tolerance for this patient. The maintenance dose is the largest dose that relieves symptoms without producing local reactions. The size and interval of doses will vary and can be adjusted as necessary. The normal interval between doses is 4 to 7 days.

Bulk extract (stock concentrate) in 50% (v/v) glycerin containing 10,000 AU/ml is supplied in 10ml, 30ml, and 50ml vials. Scratch testing in 50% (v/v) glycerin containing 10,000 AU/ml is supplied in 2ml dropper vials. Intradermal testing (aqueous) containing 100 AU/ml is supplied in 5ml vials.

These extracts should be stored at 2 to 8 degrees Celsius. Excessive heating (above room temperature) and repeated freeze-thawing should be avoided. The dating period (expiration date) is shown on the vial label. Once extracts are diluted the shelf life decreases. Extracts should be re-ordered when out of date. Please allow a minimum of three (3) weeks for delivery due to the holding period for sterility testing.