Standardized Mite Dermatophagoides farinae

1 INDICATIONS AND USAGE Greer Standardized Mite ( Dermatophagoides farinae and/or Dermatophagoides pteronyssinus ) Extracts are allergenic extracts indicated for: skin test diagnosis of mite allergy treatment of patients with mite-induced allergic asthma, rhinitis and conjunctivitis. For immunotherapy, patients must show hypersensitivity to Dermatophagoides farinae ( D. farinae ) or Dermatophagoides pteronyssinus ( D. pteronyssinus ) based on their clinical history, allergen exposure history, and skin test reactivity. Greer Standardized Mite Extracts are allergenic extracts indicated for: Diagnosis of skin test reactivity to dust mite allergen (1) Treatment of mite-induced allergic asthma, rhinitis and conjunctivitis in patients that show hypersensitivity to dust mites based on clinical history, allergen exposure history, and skin test reactivity (1)

2 DOSAGE AND ADMINISTRATION Do not inject intravenously. Greer Standardized Mite extracts are diluted with sterile diluent for allergenic extracts when used for intradermal testing or subcutaneous immunotherapy. Dosages vary by mode of administration, and by individual response and tolerance. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. Greer Standardized Mite Extracts should be a light brown solution that is free of particulate matter. If particulate matter is observed then the solution should be discarded. 2.1 Diagnostic Testing For diagnosis of a patient with a suspected allergy to either species of dust mite ( D. farinae or D. pteronyssinus ), diagnostic skin testing should include the standardized mite mixture or the single-species mite extracts. If a skin test with the standardized mite mixture elicits a positive reaction, then the single-species mite extracts can be used to determine the degree of sensitivity to each, and to guide in the selection of extracts and their concentration for immunotherapy, if indicated. A positive skin test reaction to any allergen must be interpreted in light of the patient's history of symptoms, the time of year, and known exposure to environmental allergens. 2.1.1 Percutaneous Skin Testing For percutaneous (scratch, prick, or puncture) testing, use 10,000 Allergy Units/mL Greer Standardized Mite Extract stock concentrate in dropper vials. If patient is suspected of having exquisite sensitivity, such as anaphylaxis, to certain foods and drugs, initiate percutaneous testing with several serial 10-fold dilutions of the usual test concentration. For scratch tests, scarify the skin, and then apply one drop of the extract to the scratch. For prick tests, place one drop of extract on the skin and pierce through the drop into the skin with a slight lifting motion. For puncture tests, place one drop of extract on the skin and pierce through the drop perpendicular to the skin. When using percutaneous test devices, follow the directions provided with the test devices. Include a positive control to detect false negative responses to skin testing, which may occur if serum levels of antihistamines remain from prior medication administration [see Drug Interactions (7.2)]. A glycerinated histamine phosphate diluted to 10 mg/mL (6 mg/mL histamine base) may be used as the positive control. Include a negative control to detect false positive responses, which can occur when the patient has a non-specific reaction to the diluent. A 50% glycerosaline solution may be used as the negative control. Read skin tests 15-20 minutes after exposure. Record the induration (wheal) and erythema (flare) response by noting the longest diameter of each, or by the sum of the longest erythema diameter and the mid-point orthogonal diameters of erythema (ΣE). Percutaneous testing devices often have their own grading systems, as these devices may cause different degrees of trauma to the skin and deliver different volumes of allergenic extract. Follow grading instructions for the device used. 2.1.2 Intradermal Skin Testing Intradermal tests are commonly used when the reaction to percutaneous testing is negative or equivocal but the patient has a strong clinical history of symptoms triggered by exposure to a specific allergen. Because immediate systemic reactions are more common with intradermal testing, prescreening with percutaneous testing is a practical safety measure. 1 Dilute the stock concentrate with sterile diluent. Use saline with human serum albumin (HSA), buffered saline, or saline. If prescreening is not done, or if patients are expected to be high risk, precautions should be observed since some patients have experienced anaphylaxis and death. Patients who do not react to percutaneous skin testing should be tested intradermally at a starting dose of 0.02 to 0.05 mL of a 50 Allergy Units/mL extract dilution…

5 WARNINGS AND PRECAUTIONS 5.1 Serious Systemic Reactions All concentrates of Greer Standardized Mite Extracts have the ability during skin testing and immunotherapy to elicit serious systemic reactions including anaphylactic shock and death [see Adverse Reactions (6)]. A review of the literature indicates that the incidence of near-fatal reactions to immunotherapy, defined as severe respiratory compromise, hypotension, or both, and requiring emergency treatment with epinephrine, has been estimated as 5.4 events per million injections in a 10-year retrospective survey of allergists. 3 Fatalities from immunotherapy injections have been estimated to occur at a rate of approximately one death per 2.0 to 2.8 million injections in 4-, 10- and 12-year retrospective surveys of allergists. 4-6 Because of the danger of serious reactions, caution is required in testing and treating high risk patients and those with medical conditions that reduce their ability to survive a serious systemic adverse event. High-risk patients are defined as those patients: with labile or steroid-dependent asthma, particularly in those suffering an exacerbation of their symptoms at the time of extract administration; with extreme sensitivity to a particular allergen(s); who are currently using beta blockers; who are receiving an accelerated immunotherapy build-up schedule (e.g., rush immunotherapy); who are being changed from one allergenic extract to another; who are receiving high doses of allergenic extracts. High risk patients have had fatal reactions. In addition, patients not high-risk but on beta blockers have had fatal reactions because beta blockers interfere with beta adrenergics such as epinephrine used in treatment or anaphylaxis. Patients should be kept under observation for a minimum of 30 minutes after receiving allergenic extracts so that any adverse reaction can be observed and properly handled. 2 Medications to treat systemic reactions, as well as emergency equipment should be available for immediate use. Extracts must only be administered by persons who are aware of the risk of systemic reactions, including anaphylaxis; are capable of handling such reactions; and have the necessary drugs and equipment on hand to do so. 5.2 Patients on Beta Blockers Patients receiving beta blockers may be unresponsive to the usual doses of epinephrine used to treat serious systemic reactions, including anaphylaxis. Inhalant allergy immunotherapy should be approached with caution in patients taking beta blockers. The risks of anaphylaxis in these patients should be carefully weighed against the benefits of immunotherapy [see Drug Interactions (7.1)]. 5.3 Autoimmune Disease Immunotherapy should be given cautiously to patients with other immunologic diseases and only if the risk from exposure to the allergen is greater than the risk of exacerbating the underlying disorder. 2 All concentrates of Greer Standardized Mite Extracts can cause serious systemic reactions of varying degrees of severity, including anaphylactic shock and death, particularly in patients: With labile or steroid-dependent asthma (5.1) With extreme sensitivity to allergen(s) (5.1) Who are currently using beta blockers (5.2) Who are on an accelerated immunotherapy build-up schedule (5.1) Who are being changed from one allergenic extract to another (5.1) Who are receiving high doses of allergen extracts (5.1)

4 CONTRAINDICATIONS None. None (4)

7 DRUG INTERACTIONS 7.1 Beta Adrenergic Drugs Patients receiving beta blocker drugs may not be responsive to beta adrenergic drugs used to treat anaphylaxis 10 , and may wish to temporarily postpone treatment day of skin testing. All such decisions should be made in consultation with the physician [see Warnings and Precautions (5.2)]. 7.2 Antihistamines 1 Skin testing with allergenic extracts should not be performed within 2-3 days of first-generation H 1 -histamine receptor blockers (e.g., clemastine, diphenhydramine) and within 3 to 10 days of second-generation antihistamines (e.g., loratadine, terfenadine), except for astemizole, which requires an interval of 30-60 days between allergenic extract exposure and use. These products suppress histamine skin test reactions and could mask a positive response. 7.3 Topical Corticosteroids and Topical Anesthetics 1 Topical corticosteroids may suppress skin reactivity and should be discontinued at the skin test site for at least 2-3 weeks before skin testing. Topical local anesthetics may suppress flare responses and should be avoided at skin test sites. 7.4 Tricyclic Antidepressants 1 Tricyclic antidepressants can have potent antihistamine effects and will affect skin testing. Since use of tricyclics may alter skin test results, dosing for both skin testing and immunotherapy should be done with caution. If tricyclic medication has been recently discontinued, allow 7-14 days prior to skin testing to obviate the antihistamine effect. The risk of anaphylaxis in these patients should be carefully weighed against the risks and benefits of stopping tricyclics. 7.5 Other Drugs The suppressive action of other drugs should be considered and emphasizes the need for a histamine positive-control test. Patients who are receiving beta agonists may be unresponsive to the usual doses of epinephrine used to treat serious systemic reactions, including anaphylaxis (7.1) Patients should discontinue medications known to suppress the histamine response prior to skin testing including: antihistamines (7.2), tricyclics (7.4), and topical corticosteroids and topical anesthetics (7.3)

6 ADVERSE REACTIONS Systemic reactions consist primarily of allergic symptoms, such as generalized skin erythema, urticaria, pruritus, angioedema, rhinitis, wheezing, laryngeal edema, and hypotension. Additional symptoms that are not usually associated with allergy also may occur, such as nausea, emesis, abdominal cramps, and diarrhea. Serious reactions may cause shock, loss of consciousness, and even death. Based on published studies, 7,8 systemic reactions occur in less than 1% of patients receiving conventional immunotherapy to greater than 36% in some studies of patients receiving rush immunotherapy. Local reactions at the injections site are the most commonly occurring reactions (e.g., erythema, itching, swelling, tenderness, pain). Although most adverse systemic reactions occur within 30 minutes of injection (some within minutes of extract exposure), such reactions also can occur up to six hours after skin tests or immunotherapy [see Dosage and Administration (2.2)]. 9 Systemic reactions may be fatal or near fatal (6) Systemic reactions (e.g. generalized skin erythema, urticaria, pruritus, angioedema, rhinitis, wheezing, laryngeal edema, and hypotension) occur in 4-7% of patients The most common reactions are local reactions at the injection site (e.g., erythema, itching, swelling, tenderness, pain), occuring in 26% to 82% of patients (6) To report SUSPECTED ADVERSE REACTIONS, contact Greer Laboratories, Inc., at 1-855-274-1322 or the FDA at 1-800-FDA-1088 or www.fda.gov/medwatch