Cat Hair

Studies have shown that skin tests with cat extract are useful in the diagnosis of cat allergy. As a rule, persons with cat allergy have positive skin reactions when tested with cat extract, and non-allergic individuals rarely react (7, 8, 9). However, the relationship between a positive skin test and the appearance of clinical symptoms after exposure to a cat is not absolute, i.e., some skin-test positive persons do not experience allergic symptoms after exposure (10). Failure to experience symptoms may be dose related, since it is known that cats vary significantly in the amount of Fel d1 they produce (11). The efficacy of cat extract immunotherapy in the treatment of bronchial asthma has been shown in two studies (12, 13) A reduction in bronchial sensitivity was observed in five patients with cat allergy, whereas no reduction was observed in placebo treated, cat-allergic patients.

Standardized Cat Hair Extract should not be used for immunotherapy in persons who do not have cat related allergic symptoms and a positive skin test to the extract.

Standardized Cat Hair Extract may cause local or severe life-threatening reactions when administered to highly sensitive individuals. Physicians who use this product should be familiar with the clinical use of allergenic extract and have the necessary emergency equipment and medications available to treat systematic allergic reactions See Precautions, Adverse Reactions and Overdosage . Standardized Cat Hair Extract should not be used interchangeably with Standardized Cat Pelt Extracts or previously standardized cat extracts labeled in Allergy Units per mL. Cat hair extracts labeled in BAU/mL made by other manufacturers should be tested for bioequivalency by serial titration skin testing before these products are used in patients who have previously received Allermed Standardized Cat Hair Extract. The dosage of Standardized Cat Hair Extract must be reduced when starting a patient on a new lot of Standardized Cat Hair Extract containing the same amount of Fel d1 units per mL. This is necessary due to a possible loss of potency during storage in the physician's office. The dose of the new lot of extract should not exceed 1/4 the last dose given from the old lot of extract. Any evidence of a strong local reaction or systemic reaction following the administration of Standardized Cat Hair Extract requires a reduction in dosage during the initial stages of immunotherapy, as well as during maintenance therapy.

GENERAL : Do not inject intravenously. After the needle is inserted subcutaneously, the plunger should be withdrawn slightly to check for the presence of blood in the syringe If blood is observed, a new injection should be prepared and given at another site, Observing the same precautions. The extract should be stored at 2°C-8°C. Dilutions of the 10,000 BAU/mL concentrate should be made with buffered saline containing human serum albumin for maximum stability. However, regardless of diluent type, diluted extract should be checked by skin test on a known cat-allergic individual if loss of potency is suspected. PREGNANCY CATEGORY C : Animal reproduction studies have not been conducted with Standardized Cat Hair Extract . It is also not known whether allergenic extract can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Standardized Cat Hair Extract should be given to a pregnant woman only if clearly needed. PATIENT INSTRUCTIONS : Patients should be instructed to remain in the physician's office for at least 20 minutes after skin testing and after each treatment injection, and immediately notify the physician if symptoms of a generalized reaction or shock occur. CARCINOGENESIS, MUTAGENESIS, IMPAIRMENT OF FERTILITY : Long term studies have not been conducted with Standardized Cat Hair Extract to determine their potential for carcinogenesis, mutagenesis, and impairment of fertility. NURSING MOTHERS : Data are not available on the secretion of Standardized Cat Hair Extract in human milk and it is not known what effect this might have on the nursing infant. PEDIATRIC USE : The dose of Standardized Cat Hair Extract recommended for children is the same as that used for adults, except in the injection of large doses of extract for treatment. In this case, the amount of extract given to a child may be modified so that the discomfort of the injection is minimized. DRUG INTERACTION : The skin test response to Standardized Cat Hair Extract in sensitive persons may be suppressed by previous treatment with antihistamines and drugs with antihistamine activity. Treatment with beta-blocking drugs may make patients refractory to the usual dose of epinephrine, in the event epinephrine is required to control an adverse allergic reaction. Caution should be observed in the following circumstances: EXTREME SENSITIVITY TO CATS : Determined from previous anaphylaxis following skin testing or natural exposure. AUTOIMMUNE DISEASE: Individuals with autoimmune disease may be at risk, due to the possibility of routine immunizations exacerbating symptoms of the underlying disease. MYOCARDIAL INFARCTION: Patients who have experienced a recent myocardial infarction may not be able to tolerate immunotherapy. As in all of the above circumstances, the benefit to risk ratio must be carefully evaluated Standardized Cat Hair Extract should be temporarily withheld from patients if any of the following conditions exist: (1) severe symptoms of rhinitis and/or asthma; (2) infection or flu accompanied by fever, and (3) exposure to excessive amounts of clinically relevant allergen prior to a scheduled injection.

Local Reactions From Skin Testing Large local reactions may result from skin tests with Standardized Cat Hair Extract. To help prevent this, a patient should be skin tested initially by the prick or scratch method. If a positive response is NOT observed, an intradermal skin test may be performed with a more dilute solution of the extract. Oral antihistamines and topical corticosteroids may be administered to relieve itching and swelling resulting from large skin test reactions. Local Reactions From Subcutaneous Injections The occurrence of a hive 5 to 15 minutes after the subcutaneous injection of extract is usually due to leakage of extract into the skin along the needle tract. Firm pressure (not rubbing) at the site of injection immediately after withdrawal of the needle will usually prevent this reaction. It does not require a reduction in dosage. However, a strong local reaction with erythema and edema which persists at the injection site for several hours indicates that too much extract has been given. Failure to note this response may result in a serious generalized reaction. Treatment should be altered as follows: Additional injections should not be given until all evidence of the reaction has disappeared. The next injection administered should be 50% of the last nonreacting dose or less, depending upon the size and severity of the local reaction. Subsequent injections should be continued at the reduced dosage unless the physician responsible for treatment believes that it is safe to increase the dose, and that possible clinical improvement would result from the administration of a larger dose of extract. Systemic Reactions Systemic reactions may range from a mild exacerbation of the patient's allergic symptoms to hives, anaphylactic shock, or even death from anaphylaxis. The reaction usually occurs 5 to 20 minutes after injection. As a rule, the more quickly a reaction develops, the more serious it is likely to become. Symptoms may include sneezing, coughing, itching, shortness of breath, abdominal cramps, vomiting, diarrhea, tachycardia, hypotension and respiratory failure in severe cases. The reaction is usually stopped by the subcutaneous injection of Epinephrine HCL 1:1,000 (See Overdosage below). The oral administration of antihistamines and the placement of a tourniquet proximal to the injection site are helpful adjuncts. In the event that additional measures are required, it may be necessary to treat the patient for BRONCHOSPASM with intravenous aminophylline, intravenous fluids and corticosteroids; for HYPOTENSION with vasopressors, volume repletion, isoproterenol and corticosteroids; for LARYNGEAL OBSTRUCTION with oxygen and tracheotomy and for CARDIAC ARREST with cardiopulmonary resuscitation and other appropriate measures.