What is the Extent of Safety and Efficiency of Drug Desensitization on Patients with Allergic Reactions?

1
What is the Extent of Safety and Efficiency of
Drug Desensitization on Patients with Allergic
Reactions?

• Cindy Law
• Dr. Mary Lee-Wong

2
What are Allergies?

• An abnormal sensitivity to an allergen that is
  inhaled, eaten, or touched
• An overreaction of a hypersensitive immune system
  
• Misidentification of a harmless substance as
  harmful

3
Common Types of Allergies

• Allergic rhinitis
• Food
• Medication
• Insect stings
• Latex
• chemical

4
Allergies and the Immune System

• B-lymphocytes T-lymphocytes
• Lymphocytes identifies a foreign invader
• Foreign antigens cause production of antibodies
• 5 types of immunoglobulins

5
Mast Cells and Basophils
6
Allergy Cascade
7
Anaphylaxis

• Severe allergic reaction prominent in dermal and
  systemic signs
• Common causes are food, medication, insect
  stings, and latex
• symptoms may begin in as little as five to 15
  minutes to up to two hours after exposure to the
  allergen

8
EpiPen

• epinephrine is a synthetic version of a naturally
  occurring hormone also known as adrenaline
• causes rapid constriction of blood vessels,
  reversing throat swelling, relaxing lung muscles
  to improve breathing, and stimulating the
  heartbeat.

9
Allergy Tests

• Scratch test
• Diluted extract of the possible allergen to the
  back or arm
• Scratching the skin with the needle
• Blood tests

10
Places and Symptoms of Reactions

• The sensitized immune system produces antibodies
  against allergens which cause the release of
  histamines into bloodstream

11
Treatments

• Avoidance
• Medication
• Immunotheraphy
• The injections help the immune system to produce
  fewer IgE antibodies, while also stimulating the
  production of a blocking antibody IgG

12
Drug Desensitization

• Drug Desensitization allows safe delivery of an
  antibiotic to a patient which has an IgE
  medicated sensitivity to the drug by
  administering it in small doses until a full
  therapeutic dose is clinically tolerated
• The procedure entails risk of acute allergic
  reactions, including death

13
Drug Desensitization Protocols

• 1.    Skin test patient to determine degree of
  sensitivity    a.    Dilute available drug
  solutions/suspension to 1/3 mg/ml.    b.   
  Prepare three tenfold dilutions.    c.   
  Perform prick-puncture testing with 11000
  dilution    d.    If negative, serial
  intradermal tests (0.02 ml 2-4mm bleb in
  duplicate) up to and including 3 mg/ml stock
  discontinue testing when gt8 m wheal is observed. 
  Test is positive if both duplicate wheals
  increase significantly (gt2-3 mm) 20 min after
  placement compared with diluent control.2.   
  Prepare sufficient quantities of drug
  solution/suspension for desensitization regimen
  in half-log 10 dilutions (threefold and tenfold
  dilutions from       concentrate 1-3 mg/ml).

14
Protocol Contd

• 1.    Establish baseline monitoring of patient in
  medical setting appropriate for patient's
  clinical conditions and the nature and severity
  of the prior reaction.       Start a secure
  intravenous infusion.2.    Starting dose If
  skin test negative and test is unvalidated, begin
  with 0.1 ml of 1/3 microgram/ml
  solution/suspension if skin test positive, begin
  100-fold below the dose producing a midpint (5-8
  mm wheal) reaction.3.    Route oral by
  ingestion or ng tube in 30 ml water parenteral
  by intradermal (lt0.2 ml), SC (0.2-0.6 ml), or
  intramuscular (gt0.6 ml) injection.

15
Protocol Contd

• 4.    Dosing interval 15-20 min for parenteral
  doses 20-30 min for oral dosing.  Repeat dose
  for mild systemic reaction drop back two doses
  (tenfold) for moderate reactions, further for any
  reactions producing hemodynamic changes.5.   
  Dose escalation half-log 10 (-threefold)
  increments e.g., 1 ?g, 3 ?g, 10 ?g, 30 ?g, 100
  ?g, etc.6.    If IV therapy is indicated, begin
  infusion to deliver a dose equivalent to the last
  oral/parenteral dose slowly over 1 hour. Double
  the infusion rate every       hour until target
  therapeutic dosing is achieved.

16
Penicillin Drug Desensitization
17

• Background
• A 32 year old female is pregnant and is diagnosed
  with syphilis
• Penicillin is the ideal antibiotic to treating
• The mother is allergic to penicillin
• Her obstetric history included one vaginal
  delivery at term and four subsequent spontaneous
  abortions at 12 to 16 weeks.

18
Bibliography

• .Sullivan TJ. Drug Allergy. In Midleton E, Jr.
  ed. Allergy, principles, and practice. 4th ed.
  St. Louis CV Mobsby Co, 1993 1725-1746
• .Ohman JL, Jr. Clinical and immunologic responses
  to immunotherapy. In Lockey RF, Bukantz SC, eds.
  Allergen immunotheraPY. New York Marcel Decker,
  Inc, 1991 209-232
• .Yunginger JW. Insect Allergy. In Midleton E,
  Jr, ed. Allergy, principles, and practice. 4th
  ed. St. Louis CV Mobsby Co, 1993 1511-1514
• .Patterson R, De Swarte RD, Greenberger PA, et
  al. Drug Allergy and protocols for mangement of
  drug allegies. N Engl Reg Allergy Proc 1986 7
  325.
• .In The extra pharmacopoeia. 29th ed. London
  The Pharmaceutical Press, 1989, 1189-1195
• .Monaghan MS, Glasco G, et al. Safe
  administration of iron dextran to patient who
  reacted to the test dose. South Med J 1994
  87(10) 1010-1012
• .Fishbane S, Ungureanu VD, Maesaka JK, et al. The
  Safety if intravenous iron dextran in
  hemodialysis patients. Am J Kidney Dis 1996
  28(4) 529-534
• .Novey HS, Pahl M, Haydik Y, Vaziri ND,
  Immunologic studies of anaphylaxis to iron
  destran in patients on renal dialysis. Ann
  Allergy 1994 72(3) 224-228
• .Patterson R, De Swarte RD, Greenberger PA, et
  al. Drug Allergy and protocols for managements
  to drug allergies. Allergy Proc (Spanish
  edition) 19959(2)13
• .Bridges KR, Bunn HF. Anemias with distributed
  iron metabolism. In Isselbacher KJ, Braunwald E,
  Wilson JD, et al, eds. Harrisons. Principles of
  internal medicine. 13th ed. McGraw-Hill, 1994
  1721-1723

19
Special Thanks to

• Harlem Children Society
• Dr. Sat
• Dr.Mary Lee-Wong
• Beth Israel Medical Center