5% of all hospital admissions are for a drug reaction
15% of all hospitalized patients have one or more adverse reactions
1-3% derm related is unknown
error in prescribing or patient taking wrong dosage
impaired renal function
accumulative effect over many years
most common; probably some inborn predisposition
Non-allergic secondary effects
cholasma from birth control pills, or moniliasis from antibiotic therapy, psoriasis exacerbation from beta blockers, exacerbation of hives with ASA
flu-like symptoms appearing a few hours after treatment of any stage of syphilis
assumed drug induced, a vasculitis in the skin prepared by endotoxin from existing infection -examples of localized Schwartzman would be purpura fulminans and septicemia secondary to acute meningococcemia
Immunologic reactions (small percentage)
Type I (IgE-dependent)
Mast cell release of histamine, vasoactive amines, ECF-A, leukotrienes (SRSA), and platelet-
III. Factors Concerned in Development of Sensitivity:
Age � more frequent in adults
Sex � no difference
Genetics � anaphylactoid reaction 2-3 times more common in atopic than non-atopic
Disease - approximately 50% of patients with infectious mononucleosis given ampicillin will develop drug eruption � also ampicillin should not be given to patients with lymphatic leukemia or gout, especially if they are on allopurinol
Administration � if allergic after parenteral injection, will also show allergy to oral administration
Onset of reaction � may be in minutes as in anaphylaxis, or even weeks after being off medication
Duration of sensitivity � unpredictable, so consider life long
Chemical relatives or cross sensitization � examples -common para-amino ring, also systemic and topical relationship -example sulfa
Drug interactions �example: anticoagulation and griseofulvin
Teratogenic effects of drugs or their use in pregnancy -example: staining of teeth with tetracycline
immune complex disease produced by deposition of circulating immunecomplexes in skin, kidney, or other organ, usually requires six days to develop (penicillin, sulfonamides, thiorreol, dyes, dilantin, etc.)
common offenders are penicillin, cephalosporins, opiates, dyes used in diagnostic radiology, local anesthetics, etc.
morbilliform or measles about one week after starting drug � like: barbiturates, penicillin, sulfonamides, chlorothiazides, chlorpromazines, tranquilizers, gold, streptomycin, etc. (symmetric, trunk, areas of pressure)
Toxic erythema or scarlet fever � like barbiturates, codeine, morphine, mercury, quinidine, atropine, etc.
Pityriasis Rosea � like
bismuth, gold, barbiturates, etc.
occupational hazard of physician, dentist, veterinarians, nurses (para-amino group) penicillin, streptomycin, local anesthetics, phenothiazines, sulfonamides, quinacrine, gold, etc.
Nummular eczema � like:
isoniazid, salicylic acid, and para-amino group meds, etc.
sharply delineated area of dermatitis recurring in same area on re-administration of drug, commonly occurring on buccal or genital mucosa, also palms and soles: phenolphthalein (Ex-Lax), antipyrine, salicylates, tetracycline, sulfonamides, barbiturates, quinine,vermouth, phenacetine, etc.
Erythema-multiforme (7-14 days after starting meds) -like:
penicillin, sulfonamides, phenothiazines, bromides, salicylates, chlorpropamide, thiazides, herpes infections, etc.