Allergenic Extract, Cricket

Allergenic extract is intended for use by physicians or under the guidance of physicians who are experienced in the administration of allergenic extracts for diagnosis and the emergency care of anaphylaxis. This extract is not directly interchangeable with other allergenic extracts. Patients should be instructed to recognize adverse reaction symptoms and cautioned to contact the physician's office if reaction symptoms occur. As with all allergenic extracts, severe systemic reactions may occur.In certain individuals, especially in steroid-dependent/unstable asthmatics, these life-threatening reactions may result in death.Patients should be observed for at least 20 minutes following testing. Emergency measures, as well as trained personnel, should be immediately available in the event of a life-threatening reaction.

This product should not be injected intravenously. See the "WARNINGS", "PRECAUTIONS", "ADVERSE REACTIONS" and "OVERDOSAGE" sections.

Sensitive patients may experience severe anaphylactic reactions resulting in respiratory obstruction, shock, coma and/or death.

Report serious adverse events to MedWatch, 5600 Fishers Lane, Rockville, MD 20852-9787, phone 1-800-FDA-1088.

Patients receiving beta-blockers may not be responsive to epinephrine or inhaled bronchodilators.Respiratory obstruction not responding to parenteral or inhaled bronchodilators may require theophylline, oxygen, intubation and the use of life support systems. Parenteral fluid and/or plasma expanders may be utilized for treatment of shock. Adrenocorticosteroids may be administered parenterally or intravenously. Refer to ''WARNINGS", "PRECAUTIONS" and "ADVERSE REACTIONS" sections below.

Studies indicate allergic individuals produce immunoglobulins of the IgE class in response to exposure to allergens. Subsequent exposure to the same allergen results in a complex of allergen with IgE antibody fixed on mast cells or basophil membranes. This cross-linking results in stimulation of mast cells which leads to release and generation of pharmacologically active substances that produce immediate hypersensitivity reaction.1

FOR DIAGNOSTIC USE ONLY. This product has not been shown by adequate data to be safe and effective for therapeutic use according to Federal Register Notice dated November 16, 1994, Vol. 59, No. 220. The following allergenic extracts are "For Diagnostic Use Only": Coffee (Coffea arabic), Cottonseed (Gossypium spp.), Flaxseed (Linum usitatissimum), Leafhopper (Cicadellidae), Miller Moth (Night Flying Lepidoptera), Cricket (Gryllidae) and Moth (Frenatae). These extracts are intended for diagnostic testing of patients whose histories indicate that upon natural exposure to the allergen, they experience allergic symptoms. Confirmation is determined by skin testing.

Do not administer in the presence of diseases characterized by bleeding diathesis. Individuals with autoimmune disease may be at risk of exacerbating symptoms of the underlying condition, possibly due to routine immunization. Children with nephrotic syndrome should not receive injections due to immunization exacerbating nephrotic diseases.

Allergenic extracts are not intended for diagnosing patients who do not manifest immediate hypersensitivity reactions to the allergenic extract when skin tested.

Extreme caution is necessary when using diagnostic skin tests in highly sensitive patients who have experienced severe symptoms or anaphylaxis by natural exposure or previous skin testing or treatment. IN THESE CASES THE POTENCY FOR SKIN TESTS MUST BE ADJUSTED TO THE PATIENT'S SENSITIVITY AND TOLERANCE. Refer to boxed “WARNINGS" and “OVERDOSAGE" sections.

Epinephrine 1:1000 should be available when a new lot of allergenic extract is utilized. Patient re-evaluation may be necessary. Injections should never be given intravenously. Adverse reactions to allergenic extracts are usually apparent within 20-30 minutes following skin testing. Patients should be observed for 20-30 minutes after skin testing.

General:

Sterile solutions, vials, syringes, etc. must be used. Aseptic technique should be observed in making dilutions for skin testing.

DO NOT INJECT INTRAVENOUSLY

Observe caution in making test injection to minimize adverse reactions. The usual precautions in administering allergenic extracts are necessary (refer to boxed "WARNINGS" and "OVERDOSAGE" sections). A disposable, sterile syringe and needle should be used for each individual patient to prevent transmission of serum hepatitis, Human Immunodeficiency Virus (HIV) and other infectious agents.

It cannot be overemphasized that, under certain unpredictable combinations of circumstances, anaphylactic shock is always a possibility. Other possible systemic reaction symptoms are, in varying degrees of severity: fainting, pallor, bradycardia, hypotension, angioedema, cough, wheezing, conjunctivitis, rhinitis, and urticaria.4,5

With careful attention to administration, such reactions occur infrequently, but it must be remembered that allergenic extracts are highly potent to sensitive individuals and overdose could result in anaphylactic symptoms. Therefore, it is imperative that physicians administering allergenic extracts understand and be prepared for the treatment of severe reactions.

Refer to "OVERDOSAGE" section for a description of the treatment of anaphylactic reactions.

Information for Patients:

Patients should remain under observation of nurse, physician, or other personnel trained in emergency measures for at least 20 minutes following testing. Any adverse reactions during or after leaving the office should be reported to the physician or their qualified personnel.

Carcinogenesis, Mutagenesis, Impairment of Fertility:

Long term studies in animals have not been conducted with allergenic extract to determine their potential for carcinogenicity, mutagenicity or impairment of fertility.

Pregnancy Category C:

Animal reproduction studies have not been conducted with allergenic extracts. It is not known whether allergenic extracts cause fetal harm during pregnancy or affect reproductive capacity. A systemic reaction to allergenic extract could cause uterine contractions leading to spontaneous abortion or premature labor. Allergenic extracts should be used during pregnancy only if potential benefit justifies potential risk to fetus.3

Nursing Mothers:

It is not known whether allergenic extracts are excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when allergenic extracts are administered to a nursing woman.

Pediatric Use:

Allergenic extracts have been used routinely in children, and no special safety problems or specific hazards have been found.7,8

Drug Interactions:

Antihistamines. Antihistamines inhibit the wheal and flare reaction. The inhibitory effect of conventional antihistamines varies from 1 day up to 10 days, according to the drug and patient's sensitivity. Long acting antihistamines (e.g., astemizole) may inhibit the wheal and flare for up to forty days.

Imipramines, phenothiazines, and tranquilizers. Tricyclic antidepressants exert a potent and sustained decrease of skin reactions to histamine that may last for a few weeks. Tranquilizers and antiemetic agents of the phenothiazine class have H1 antihistaminic activity and can block skin tests.2

Corticosteroids. Short-term (less than 1 week) administration of corticosteroids at the therapeutic doses used in asthmatic patients does not modify the cutaneous reactivity to histamine, compound 48/80, or allergen. Long-term corticosteroid therapy modifies the skin texture and makes the interpretation of immediate skin tests more difftcult.2

Theophylline. It appears that theophylline need not be stopped prior to skin testing. 2

Beta-adrenergic agents. Inhaled beta2 agonists in the routine doses for the treatment of asthma do not usually inhibit allergen-induced skin tests. However, oral terbutaline and parenteral ephedrine were shown to decrease the allergen-induced wheal.2

Cromolyn. Cromolyn inhaled or injected prior to skin tests with allergens or degranulating agents does not alter the skin whealing response.2

Other drugs. Other drugs have been shown to decrease skin test reactivity. Among them, dopamine is the best-documented compound.2