Standardized Short Ragweed Pollen

Standardized Short Ragweed Pollen Manufacturers

• Antigen Laboratories, Inc.
  

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  Standardized Short Ragweed Pollen | Antigen Laboratories, Inc.

  

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  DOSAGE AND ADMINISTRATION
      Refer to “STORAGE” section for proper storage condition for allergenic extract.
      Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.  Some allergenic extracts naturally precipitate.
      Physicians undertaking immunotherapy should be concerned with patient’s degree of sensitivity.  The initial dilution of allergenic extract, starting dose, and progression of dosage must be carefully determined on the basis of the patient’s history and results of skin tests.  (See “INDICATIONS AND USAGE” section.)  Strongly positive skin tests may be risk factors for systemic reactions.  Less aggressive immunotherapy schedules may be indicated for such patients.
      PRICK-PUNCTURE TESTING:  To identify short ragweed sensitive individuals and as a safety precaution, it is recommended that a prick or puncture test be performed prior to initiating very dilute intradermal testing.  Prick (puncture) testing is performed by placing a drop of extract on skin and puncturing skin through the drop with a small needle such as a bifurcated vaccinating needle.  The most satisfactory sites on the back for skin testing are from posterior axillary fold to 2.5 cm from the spinal column, and from the top of the scapula to the lower rib margins.  The best areas on the arms are the volar surfaces from the axilla to 2.5 or 5 cm above the wrist, skipping the anticubital space.  A positive reaction is approximately 10-15 mm erythema with 2.5 mm wheal.
      Smaller, less conclusive reactions may be considered positive in conjunction with a definitive history of symptoms on exposure to allergen.  Less sensitive individuals can be tested intradermally with appropriately diluted extract.  (See Intradermal Testing.)
      A positive control using histamine phosphate identifies patients whose skin may not react due to medications, metabolic or other reasons.  A negative diluent control would exclude false-positive reactions due to ingredients in diluent or patients who have dermatographism.
   
  

  SERIAL DILUTIONS
  APPROXIMATE AU/ml RESULTING FROM 1:5 DILUTION
  OF ALLERGENIC EXTRACT CONCENTRATE DILUTION # DILUTION EXPONENT
  100,000 AU/ml
  No. 1
  5-1
  20,000
  No. 2
  5-2
  4,000
  No. 3
  5-3
  800
  No. 4
  5-4
  160
  No. 5
  5-5
  32
  No. 6
  5-6
  6.4
  No. 7
  5-7
  1.28
  No. 8
  5-8
  0.256
  No. 9
  5-9
  0.0512
  No. 10
  5-10
  0.01024
  No. 11
  5-11
  0.002048
  

  
  

  SERIAL DILUTIONS
  APPROXIMATE AU/ml RESULTING FROM 1:10 DILUTION
  OF ALLERGENIC EXTRACT CONCENTRATE
  DILUTION #
  DILUTION EXPONENT
  100,000 AU/ml
  No. 1
  10-1
  10,000
  No. 2
  10-2
  1,000
  No. 3
  10-3
  100
  No. 4
  10-4
  10
  No. 5
  10-5
  1
  No. 6
  10-6
  0.1
  No. 7
  10-7
  0.01
  No. 8
  10-8
  0.001
  No. 9
  10-9
  0.0001
  No. 10
  10-10
  0.00001
  

  
      INTRADERMAL TESTING: Upper or lower arm is the usual location for skin testing. A sterile, disposable syringe and needle is used for each extract tested.  Intracutaneous test dilutions should be made with aqueous diluent.  Three-fold, five-fold or ten-fold dilutions may be prepared from stock concentrates. (1) Start testing with the most dilute allergenic extract concentration.  (2) A volume of 0.01-0.02 ml should be injected slowly into the superficial skin layers making a small bleb (superficial wheal).  (3) An initial skin test with 0.001 AU/ml (10-8 or 5-11 dilution) is considered safe for patients with suspected short ragweed sensitivity.  Reactions to skin testing are graded 0 to 4+ according to size of wheal and erythema produced (refer to chart below).  The reactions should be read after fifteen minutes.
  
  

  GRADE
  mm ERYTHEMA
  mm WHEAL
  0
  less than 5
  less than 5
  +
  5-10
  5-10
  1+
  11-20
  5-10
  2+
  21-30
  5-10
  3+
  31-40
  10-15
  or with pseudopods
  4+
  greater than 40
  greater than 15
  or with many pseudopods
  

  
      If after twenty minutes no skin reaction is observed, continue testing using increments of the concentration until a reaction of 5-10 mm wheal and 10-30 mm erythema is obtained, or a concentration of 5-2 or 10-1 has been tested.  A positive control of histamine phosphate and a negative control of 50% v/v glycerine diluted with diluent to 5-2 (1:25) or 10-1 (1:10) dilution, should be included in interpretation of intradermal testing.1
      INTRADERMAL TESTING--SKIN ENDPOINT TITRATION: Patient’s degree of sensitivity and the initial dose of allergen to be used in immunotherapy can be quantitated using five-fold dilutions of allergenic extract for intracutaneous testing.  A concentration of 0.001 AU/ml (5-11 dilution) is a safe initial dilution.  A sequence of 5-fold dilutions of an allergen are injected intracutaneously (0.01-0.02 ml) to form 4 mm diameter superficial wheals.  After 15 minutes the endpoint is determined by noting the dilution that first produces a wheal and erythema 2 mm larger than dilutions that produce a 5 mm or negative wheal.  The endpoint dilution is used as a starting dose concentration for immunotherapy.
      Normally, immunotherapy can be started with 0.15 ml of the dilution of allergenic extract causing the endpoint reaction.  In any allergenic patient, a safe starting dose can be determined by finding the first dose by intradermal skin testing producing a 1+ reaction or the dilution producing the skin endpoint.
      Increasing doses of 5-20% increments can be administered providing initial or preceding dose is tolerated without significant local reactions.  The rate of increase in dosage in the early stages of treatment with highly diluted extracts is usually more rapid than the rate of increase possible with more concentrated extracts.  This schedule is intended only as a guide and must be modified to the reactivity of the individual patient.  Physicians must proceed cautiously in the treatment of highly sensitive patients who develop large local or systemic reactions.
      Some patients may tolerate larger doses of the allergenic extract depending on patient response.3
  Because diluted extract tends to lose activity on storage, the first dose from a more concentrated vial should be the same or less than the previous dose.4,7
      Dosages progressively increase according to the tolerance of the patient at intervals of one to seven days until, (1) the maintenance dose is reached (the “optimal” tolerated dose for each individual); (2) the patient achieves relief of symptoms; (3) induration at the site of injection is no larger than 50 mm in 36 to 48 hours.  Maintenance dose may be continued at regular intervals perennially.  It may be necessary to adjust the progression of dosage downward to avoid local and systemic reactions during ragweed pollen season.
      The usual duration of treatment has not been established.  A period of two or three years on immunotherapy constitutes an average minimum course of treatment.
      Clinical studies indicate the “optimal” immunotherapy dose of 2000 AU/ml (range of 1000-4000 AU/ml) consistently provides clinical relief for short ragweed sensitive patients.  Physician should be forewarned that peak dose in this range is more commonly associated with severe systemic reactions than doses below 1000 AU/ml.  Dose may need adjusting downward for extremely sensitive patients or during periods of increased pollen exposure.  Patients unable to tolerate target dose should be treated with lower immunizing dose.1,17
  

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