Drug Allergies Flashcards
(26 cards)
What is a type-2 reaction
Occurs in minutes - days
Examples: hemolytic anemia, thrombocytopenia
Type 3 reaction
Immune complex rxn
Ex: drug induced lupus, serum sickness
Type 4 rxn
Delayed hypersensitivity (48h-wks after)
Ex: PPD tb skin test
Type A reaction
Dose dependent and predictable
Ex: doxazosin 1 mg qhs titrated up to 4 mg to decrease type a rxn of orthostatic hypotension
Type B reaction
Idiosyncratic (not predictable) drug rxn
Where should side effects/adverse events/allergies be reported
FDA medwatch program (FDA’s adverse event reporting system - FAERS) exception: VACCINES - reported in VAERS
what is used to determine if a drug is the cause of a rxn?
The Naranjo Scale
Drugs associated with photosensitivity
SULFA ANTIBIOTICS TETRACYCLINES NSAIDs Amiodarone Chloroquine Oral/topical retinoids Coal tar Quinine Fluoroquinolones Griseofulvin Tarcolimus Thiazides and loop diuretics St. John's wort Cyclosporine Tigecycline Voriconazole
Drugs that can cause Stevens johnsons syndrome or toxic epidermal necrolysis
Sulfamethoxazole Allopurinol Carbamazepine Clindamycin Oxcarbazepine Phenobarbital Ethosuximide Lamotrigine Phenytoin/fosphenytoin Clopidogrel Ticlopidine Quinine Abacavir Nevirapine Letrozole Hydrochloroquine Piroxicam Minocycline/doxycycline Taigabine Zonisamide
Common drugs that cause drug rxn with eosinophilia and systemic symptoms (DRESS)
Ethosuximide
Carbamazepine
Phenytoin/fosphenytoin
Minocycline/doxycycline
Drugs that can cause thrombotic thrombocytopenic purpura (TTP)
Cloud often Ticlopidine Sulfamethoxazole Quinine Acyclovir/valacyclovir/famciclovir
Treatment for SJS and TEN
Stop offending agent Can use corticosteroids in SJS BUT CONTRAINDICATED IN TEN ANTIBIOTICS CONTROL PAIN WITH OPIOIDS Fluid/lytes
Symptoms/signs of TEN And SJS
Severe exposive mucosal erosions
High temp
Damage to organs
SJS can lead to TEN
DRESS symptoms
Skin eruptions
Fever, hepatic/renal dysfunction
Lymphadenopathy
DRESS treatment
Stop offending agent
Symptoms may worsen for a period of time
TTP symptoms
Purpura and petechiae
TTP tx
Emergent plasma exchange
What two drug classes cause most drug allergies
Penicillins and sulfonamides
Treatments of drug reactions
Non breathing difficulty - stopping causative agent (sometimes)
Antihistamines - decrease swelling and rash
Steroids - severe swelling (needs injection)
NSAIDS - decrease swelling
Epinephrine - reverses bronchoconstriction
Epi pen instructions
Jab into outer thigh at a 90 degree angle (through clothes if necessary)
Count to 5 slowly
Remove injector and rub area
If needle is showing you received the dose, if not inject again
If needed used second pen the opposite outer thigh
Take 2 antihistamine tablets
What is a type-1 reaction
Immediate
Severity- minor to death
Beta lactam allergy - what to avoid
Pcns ALL
potential cephalosporin allergy also: cephalosporin and carabapenem
Ppl with sulfa allergies should avoid
Sulfamethoxazole Sulfapyridine Sulfadiazine Sulfisoxazole Look at book for more info!
Side effects of true allergy to NSAIDS
Urticaria
Angioedema
+/-anaphylaxis
On exam even avoid COX2 selectives but used clinically
