Overview
11 DESCRIPTION Spherusol ® is a sterile aqueous solution of extracts of C. immitis spherules. The multi-dose vial contains 0.9% sodium chloride and 0.014% sodium borate with 0.4% phenol as a preservative. Residual thimerosal from the manufacturing process is present at a concentration of ≤0.0001% (
Mechanism of Action
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action In individuals with a history of pulmonary coccidioidomycosis Spherusol ® is thought to elicit a cellular immune reaction to C. immitis , as evidenced by a delayed-type hypersensitivity (DTH) response to Coccidioidin (1,2,3,4) . The general mechanism of the DTH response is based on the interaction of antigen with CD 4 and CD 8 lymphocytes followed by the secretion of interleukins and other lymphokines from macrophage cells. The release of effector molecules causes endothelial cells lining the blood vessels to become permeable and allows fibrinogen to escape into the surrounding tissue where it is converted to fibrin.
Indications
- 1 INDICATIONS AND USAGE Spherusol ® is a skin test antigen indicated for the detection of delayed-type hypersensitivity to Coccidioides immitis in individuals with a history of pulmonary coccidioidomycosis. Spherusol ® is approved for use in individuals 18-64 years of age. The use of Spherusol ® to detect delayed-type hypersensitivity responses in a general population with unknown exposure to C. immitis has not been evaluated. Persons with acute or disseminated coccidioidomycosis may not develop a delayed-type hypersensitivity response to Spherusol ® .
Common Doses
- 0.1 mL
- 1.0 mL
Dosage
2 DOSAGE AND ADMINISTRATION A single 0.1 mL intradermal injection. Induration at injection site to be evaluated 48 hours after administration. ( 2.1 , 2.3 ) 2.1 Preparation for Administration Spherusol ® is a clear, colorless sterile solution for intradermal administration. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. If any of these conditions exists, the skin test antigen should not be administered. 2.2 Administration: Spherusol ® is administered as a 0.
Black Box Warning
WARNING The expected response to Spherusol ® is a local area of inflammation at the site of the skin test. The reaction is usually dime to quarter size reaching maximum diameter between 24 and 48 hours. Larger accelerated reactions can occur, which may require treatment with local cold compresses and anti-inflammatory medication. ( 2.3 , 6.1 ) Systemic reactions can occur with skin test antigens and in certain individuals these reactions may be life-threatening or cause death. Emergency measures and personnel trained in their use should be immediately available.
Contraindications
- 4 CONTRAINDICATIONS A severe allergic reaction (e.g., anaphylaxis) to Spherusol ® , or any component of Spherusol ® or other coccidioidin products is a contraindication to administration. Severe allergic reaction (e.g., anaphylaxis) to Spherusol ® , or any component of Spherusol ® or other coccidioidin products. ( 4 )
Side Effects
- 6 ADVERSE REACTIONS The most commonly reported local adverse reactions were itching and swelling (>75%) and pain (>15%) within 7 days of administration.( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Nielsen Biosciences, Inc. at (855) 855-1212 or Food and Drug Administration (FDA) at 1-800-332-1088 or www.vaers.hhs.gov . ( 6.3 ) 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a skin test antigen cannot be directly compared to rates in the clinical trials of another skin test...
Interactions
- 7 DRUG INTERACTIONS Corticosteroids and immunosuppressive agents may suppress the response to the skin test.( 7.1 ) 7.1 Corticosteroids and Immunosuppressives Corticosteroids and Immunosuppressive agents may suppress the response to the skin test. Pharmacologic doses of corticosteroids may suppress the response to skin test antigens after two weeks of therapy. The mechanism of suppression is thought to involve a decrease in monocytes and lymphocytes, particularly T-cells. The normal DTH response usually returns to pre-treatment levels within several weeks after steroid therapy is discontinued.