STANDARDIZED CAT PELT — felis catus dander injection, solution
Jubilant HollisterStier LLC
Allergenic extracts may potentially elicit a severe life-threatening systemic reaction, rarely resulting in death.1 Therefore, emergency measures and personnel trained in their use must be available immediately in the event of such a reaction. Patients should be instructed to recognize adverse reaction symptoms and cautioned to contact the physician’s office if symptoms occur.
This standardized extract may be more potent than regular extracts and therefore is not directly interchangeable with our non-standardized extracts, or other manufacturers’ products. Standardized pelt and hair extracts are manufactured from different source materials and are not interchangeable. Standardized cat extracts labeled in AU/mL are not interchangeable with extracts labeled in BAU/mL. See DESCRIPTION Section.
This product should never be injected intravenously.WARNINGS, PRECAUTIONS, ADVERSE REACTIONS and OVERDOSE Sections for further discussion.
Allergenic extracts for subcutaneous injection and prick or puncture for diagnosis are sterile solutions containing the extractables of the source material and components of the extraction fluid. Standardized Cat Pelt is available as an extract from acetone precipitated source material in two different extraction fluids described below.
Cat Pelt source material consists of hair and whole epidermis which have undergone an acetone precipitation process. AP™ Acetone Precipitated Cat Pelt is derived from precipitate formed when acetone is added to an aqueous extract.
Glycero-Coca’s: Contains 0.5% sodium chloride, 0.275% sodium bicarbonate, and 50% glycerin (v/v) as a preservative.
1. Bioequivalent Allergy Units. When originally licensed, standardized cat extracts containing 10 — 20 Fel d 1 units/mL were arbitrarily assigned 100,000 Allergy Units (AU)/mL. Subsequently, quantitative skin testing by the ID50 EAL method 23 was used to determine that standardized cat extracts containing 10 to 19.9 Fel d 1 units/mL should be assigned 10,000 AU/mL rather than 100,000 AU/mL. To avoid possible confusion about this change in allergy unit assignment, the nomenclature changed for cat extracts, and such products are labeled in Bioequivalent Allergy Units (BAU/mL).
Each lot of Standardized Cat Pelt extract is standardized by quantitating the Fel d 1 content based on standards on file with the Center for Biologics Evaluation and Research (CBER) of the U.S.
Food and Drug Administration. Test extracts are diffused in agar containing standard anti-serum to Fel d 1 and compared to the diffusion of a reference cat allergen preparation.2 The potency of the extract is expressed as units of Fel d 1 per mL, and extracts containing 10-19.9 Fel d 1 units per mL are labeled at 10,000 BAU/mL.
It has been recognized that there are differences in the levels of non Fel d 1 allergens among standardized cat extracts which utilize different source materials. Isoelectric focusing (IEF) patterns have been shown to be predictive of the presence of non Fel d 1 allergens. Therefore, each lot of Standardized Cat Pelt is compared by IEF to a Cat Pelt Extract Reference and a Cat Hair Extract Reference on file with the CBER. The labeled name of the cat extract (i.e., Cat Hair Extract or Cat Pelt Extract) must be supported by matching the IEF profile of the corresponding reference.
2. Concentrate. Concentrate label terminology applies to allergenic extract mixtures where the individual allergens being combined vary in strength or the designation of strength.
|50%||Short Ragweed 1:20 w/v|
|25%||Std. Cat Pelt 10,000 BAU/mL|
|25%||Std. Mite D. farinae 10,000 AU/mL|
Should the physician choose to calculate the actual strength of each component in the “Concentrate” mixture, the following formulation may be used:
|Actual Allergen Strength in concentrate Mixture||=||Allergen Manufacturing Strength||x||% Allergen in Formulation (by volume or parts)|
Active ingredients are the allergen(s) noted on the vial label. Preservative is 50% (v/v) glycerin. Glycerinated extracts contain 0.5% sodium chloride, 0.275% sodium bicarbonate and 50% glycerin (v/v) as a preservative.
13 The mechanisms by which hyposensitization is achieved are not completely understood. It has been shown that repeated injections of appropriate allergenic extracts will ameliorate the intensity of allergic symptoms upon contact with the allergen.6, 7, 8, 9 Clinical studies which address the efficacy of immunotherapy are available. The allergens which have been studied are cat, mite, and some pollen extracts.10, 11, 12, 13, 14, 15 IgE antibodies bound to receptors on mast cell membranes are required for the allergic reaction, and their level is probably related to serum IgE concentrations. Immunotherapy has been associated with decreased levels of IgE, and also with increases in allergen specific IgG “blocking” antibody. The histamine release response of circulating basophils to a specific allergen is reduced in some patients by immunotherapy, but the mechanism of this change is not yet clear. The relationships among changes in blocking antibody, reaginic antibody, and mediator-releasing cells, and successful immunotherapy need study and clarification.
3, 16, 17, 18 Allergenic extracts are indicated for use in diagnosis and immunotherapy of patients presenting symptoms of allergy (hay fever, rhinitis, etc.) to specific environmental allergens. The selection of allergenic extracts to be used should be based on a thorough and carefully taken history of hypersensitivity, and confirmed by skin testing.19, 20
The use of mixed or unrelated antigens for skin testing is not recommended since, in the case of a positive reaction, it does not indicate which component of the mix is responsible for the reaction, while, in the case of a negative reaction, it fails to indicate whether the individual antigens at full concentration would give a positive reaction. Utilization of such mixes for compounding a treatment may result, in the former case, in administering unnecessary antigens and, in the latter case, in the omission of a needed allergen.
Avoidance of allergens is to be advocated if possible, but cannot always be attained, e.g., allergy to cat dander in kennel owners and employees, cat breeders, research workers, veterinarians, etc.
There are no known absolute contraindications to immunotherapy. See PRECAUTIONS for pregnancy risks.
Patients with cardiovascular diseases or pulmonary diseases such as symptomatic asthma, and/or those who are receiving cardiovascular drugs such as beta blockers, may be at higher risk for severe adverse reactions. These patients may also be more refractory to the normal allergy treatment regimen. Patients should be treated only if the benefit of treatment outweighs the risks. 1
Any injections, including immunotherapy, should be avoided in patients with a bleeding tendency. Since there are differences of opinion concerning the possibility of routine immunizations exacerbating autoimmune diseases, immunotherapy should be given cautiously to patients with autoimmune diseases and only if the risk from exposure is greater than the risk of exacerbating the autoimmune process.
See WARNINGS at the beginning of this instruction sheet. Allergenic extract should be temporarily withheld from patients or the dose adjusted downward if any of the following conditions exist: (1) severe symptoms of rhinitis and/or asthma; (2) infection or flu accompanied by fever; or (3) exposure to excessive amounts of clinically relevant allergen prior to a scheduled injection. Do not start immunotherapy during a period of symptoms due to exposure. Since the individual components of the extract are those to which the patient is allergic, and to which s/he will be exposed, typical allergic symptoms may follow shortly after the injection, particularly when the antigen load from exposure plus the injected antigen exceeds the patient’s antigen tolerance.
IF THE PREVIOUS EXTRACT WAS NON-STANDARDIZED OR WAS STANDARDIZED AND LABELED IN ALLERGY UNITS PER mL (AU/mL): This standardized extract may be more potent than non-standardized extracts. Initiate therapy as though patient had not been receiving immunotherapy, or determine initial dose by skin test using serial dilutions of the extract. See PRECAUTIONS and DOSAGE AND ADMINISTRATION Sections.
IF CHANGING TO A DIFFERENT LOT OF EXTRACT: Even though it is the same formula and concentration, the first dose of the new extract should not exceed 50% of the last administered dose from the previous extract.
IF THE EXTRACT PREVIOUSLY USED WAS FROM ANOTHER MANUFACTURER: Since manufacturing processes and sources of raw materials differ among manufacturers, the interchangeability of extracts from different manufacturers cannot be insured. The starting dose of the extract therefore should be greatly decreased even though the extract is the same formula and dilution. Initiate therapy as though patient had not been receiving immunotherapy, or determine initial dose by skin test using serial dilutions of the extract. See DOSAGE AND ADMINISTRATION and ADVERSE REACTIONS Sections.
IF A PROLONGED PERIOD OF TIME HAS ELAPSED SINCE THE LAST INJECTION: Patients may lose tolerance for allergen injections during prolonged periods between doses. The duration of tolerance is an individual characteristic and varies from patient to patient. In general, the longer the lapse in the injection schedule, the greater dose reduction required. If the interval since last dose is over four weeks, perform skin tests to determine starting dose.
IF THE PREVIOUS EXTRACT WAS OUTDATED: The dating period for allergenic extracts indicates the time that they can be expected to remain potent under refrigerated storage conditions (2° — 8°C). During the storage of extracts, even under ideal conditions, some loss of potency occurs. For this reason, extracts should not be used beyond their expiration date. If a patient has been receiving injections of an outdated extract, he may experience excessive local or systemic reactions when changed to a new, and possibly more potent, extract. In general, the longer the material has been outdated, the greater the dose reduction necessary for the fresh extract.
IF CHANGING FROM ALUM-ADSORBED TO AQUEOUS OR GLYCERINATED EXTRACTS: When the patient previously has been receiving alum-adsorbed or alum-precipitated extract, the safest course is to start over as though the patient had not been receiving immunotherapy. See DOSAGE AND ADMINISTRATION and ADVERSE REACTIONS in product instructions. IF ANY OTHER CHANGES HAVE BEEN MADE IN THE EXTRACT CONCENTRATE FORMULA: Changes other than those listed above may include situations such as a redistribution of component parts or percentages, a difference in extracting fluid (i.e., change from non-glycerin extracts to 50% glycerin extracts), combining two or more stock concentrates, or any other change. It should be recognized that any change in formula can affect a patient’s tolerance of the treatment. The usual 1/2 of the previous dose for a new extract may produce an adverse reaction: extra dilutions are recommended whenever starting a revised formula. The greater the change, the greater the number of dilutions required.
Proper selection of the dose and careful injection should prevent most systemic reactions. It must be remembered, however, that allergenic extracts are highly potent in sensitive individuals, and that systemic reactions of varying degrees of severity may occur, including urticaria, rhinitis, conjunctivitis, wheezing, coughing, angioedema, hypotension, bradycardia, pallor, laryngeal edema, fainting, or even anaphylactic shock and death. Patients should be informed of this, and the precautions should be discussed prior to immunotherapy. (See PRECAUTIONS below.) Severe systemic reactions should be treated as indicated in the ADVERSE REACTIONS Section. Refer to boxed WARNINGS Section.
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