Overview
DESCRIPTION Mite extract is a sterile solution containing the extractables of mite whole bodies in 0.25% sodium chloride, 0.125% sodium bicarbonate, 50% glycerol by volume and 0.4% phenol as a preservative. The mites are grown on a medium of yeast and pork and are handled and cleaned in a manner to remove more than 99% of the food medium. The medium contains no material of human origin.
Mechanism of Action
CLINICAL PHARMACOLOGY The mechanism for the pharmacologic action of allergenic extracts used diagnostically is based on the liberation of histamine and other substances when the allergen reacts with IgE antibody attached to mast cells. The mechanism of the therapeutic effect is not well understood and further research is required to substantiate current hypotheses. Mites belonging to the genus Dermatophagoides are found in approximately 80% of house dust samples throughout the world (2,3). D. farinae is common in much of the United States (3), although D. pteronyssinus is predominant in certain coastal regions and both species are commonly found in homes (4,5). The diagnosis of mite allergy is established by the allergy history and skin test reactivity (6,7).
Indications
- 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).
Common Doses
- 0.05 mL
- 0.2 mL
- 1.0 mL
- 9.0 mL
Dosage
DOSAGE AND ADMINISTRATION Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. The product should be discarded if discoloration or particles are observed. DIAGNOSTIC USE: Percutaneous Tests : The skin test concentration of 10,000 AU/mL in dropper vials is used for scratch or prick-puncture testing. Puncture tests performed with D. farinae extract on 5 persons sensitive to mite showed a mean diameter wheal of 8.8 mm ± 1.8 mm and mean diameter erythema of 39.2 mm ± 5.3 mm.
Black Box Warning
WARNINGS This product is intended for use by physicians who are experienced in the administration of allergenic extracts or for use under the guidance of an allergy specialist. The initial dose must be based on skin testing as described in the dosage and administration section of this insert. Patients being switched from alum-absorbed or other types of precipitated extracts or non-standardized extracts to this extract should be started as though they were coming under treatment for the first time.
Contraindications
- CONTRAINDICATIONS Injections of mite extract should not be administered in the presence of diseases characterized by a bleeding diathesis. Immunotherapy should not be started in patients until a specific diagnosis of Type I allergy to mite is made by a physician based on skin testing with this product. Other contraindications include: EXTREME SENSITIVITY TO MITE: Determined from previous anaphylaxis following skin testing, immunotherapy, or natural exposure.
Side Effects
- ADVERSE REACTIONS Adverse systemic reactions usually occur within minutes and consist primarily of allergic symptoms such as generalized skin erythema, urticaria, pruritus, angioedema, rhinitis, wheezing, laryngeal edema and hypotension. Less commonly, nausea, emesis, abdominal cramps, diarrhea and uterine contractions may occur. Severe reactions may cause shock and loss of consciousness. Fatalities have occurred rarely (11). Systemic reactions occur with varying frequency in different clinics.
Interactions
- No major interactions listed on the FDA label. Always consult a healthcare professional.