House Dust Mite, Dermatophagoides pteronyssinus

INDICATIONS AND USAGE Standardized mite extract is indicated for use in the diagnosis of patients with a history of allergy to mites or house dust and for the treatment of patients with a history of mite allergy who have established sensitivity to mites by diagnostic skin testing. The use of mite extract for the above purposes should be made only by physicians with special familiarity and knowledge of allergy as described in a standard allergy textbook (10).

WARNINGS Concentrated extract must be diluted with sterile diluent prior to first use on a patient for treatment or intradermal testing. All concentrates of allergenic extract are manufactured to assure high potency and therefore have the ability to cause serious local and systemic reactions, including death in sensitive patients (11). Patients should be informed of this risk and precautions should be discussed prior to initiating immunotherapy (see PRECAUTIONS below). 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; 3) exposure to excessive amounts of clinically relevant allergen prior to a scheduled injection. The dosage must be reduced when starting a patient on fresh standardized mite extract or when transferring a patient from non-standardized or modified extract to standardized extract, even though the labeled strength of the old and new vials may be the same. This is necessary due to a loss of extract potency during storage in the physician's office. The mite allergen content of old and new extract may be compared and adjusted by dosage reduction and/or dilution before the new extract is administered. The amount of new extract given should not exceed 25% of the last dose given from the old vial, assuming both extracts contain comparable amounts of mite allergen. Any evidence of a local or generalized reaction requires a reduction in dosage during the initial stages of immunotherapy, as well as during maintenance therapy. Beta-blocking drugs may make patients refractory to the usual dose of epinephrine, in the event epinephrine is required to treat an adverse allergic reaction.