Key Points
ÎThe p-i concept (pharmacologic interaction with immune receptors) is a new classification of drug hypersensitivity in which a drug binds noncovalently to a T-cell receptor, which may lead to an immune response via interaction with a major histocompatibility complex receptor. (C)
ÎFrom a clinical standpoint, the most practical method of classifying drug reactions is by indicating the various tissue and organ systems affected. (D)
ÎThe structural characteristics of drugs and biological products may permit predictions about what type of hypersensitivity reactions to expect from certain classes of therapeutic substances. (C)
Table 1. Drug Allergic Reactions and Syndromes Type
IgE mediated Cytotoxic Immune complex
Delayed type hypersensitivity
Hypersensitivity vasculitis
DRESS
Pulmonary drug hypersensitivity
Systemic DILE Cutaneous DILE
Drug-induced granulomatous disease
Blistering disorders
Serum sickness-like reactions
Immunologic nephropathy
4
Urticaria, angioedema, bronchospasm, anaphylaxis
Hemolytic anemia, thrombocytopenia, granulocytopenia
Serum sickness
Contact dermatitis, exanthems
Cutaneous or visceral vasculitis
Cutaneous, fever, eosinophilia, hepatic dysfunction, lymphadenopathy
Pneumonitis, fibrosis
Arthralgias, myalgias, fever, malaise
Erythematous/ scaly plaques in photodistribution
Churg-Strauss syndrome, Wegener's granulomatosis
Immunologic hepatitis Hepatitis, cholestatic jaundice
Erythema multiforme, SJS, TEN
Erythema multiforme, arthralgias
Interstitial nephritis, membranous glomerulonephritis
Clinical Manifestations Examples of Causative Agents β-Lactam antibiotics, platinum-
based chemotherapeutics, perioperative agents
Penicillin, quinine, sulfonamides
Penicillin, infliximab, thymoglobulin
Neomycin, glucocorticoids, penicillin, sulfonamide antibiotics
Hydralazine, penicillamine, propylthiouracil
Anticonvulsants, sulfonamides, minocycline, allopurinol
Nitrofurantoin, bleomycin, methotrexate
Hydralazine, procainamide, isoniazid
Hydrochlorothiazide, calcium channel blockers, ACE inhibitors
Propylthiouracil, leukotriene modifiers
Para-aminosalicylic acid, sulfonamides, phenothiazines
Sulfonamides, cephalosporins, imidazole anticonvulsants, NSAIDs
Cefaclor, cefprozil
Penicillin, sulfonamides, gold, penicillamine, allopurinol
