Drug reactions can be classified in many ways. One useful approach is to separate predictable reactions occurring in normal patients from unpredictable reactions occurring in susceptible patients.
Predictable adverse reactions;
• Over dosage (wrong dosage or defect in drug metabolism)
• Side effects (sleepiness from antihistamines)
• Indirect effects (antibiotics changing normal flora)
• Drug interactions (altered metabolism of drugs; most commonly involving the cytochrome P-450 enzymes)
Unpredictable adverse reactions
• Allergic reaction (drug allergy or hypersensitivity; immunologic reaction to drug; requires previous exposure or cross-reaction)
• Pseudo allergic reaction (non-immunologic activation of mast cells).
• Idiosyncratic reaction (unexplained reaction, not related to mechanism of action, without known or suspected immunologic mechanism).
Note: 80% of allergic and pseudo allergic drug reactions are caused by Beta-lactam antibiotics, aspirin, NSAIDs, and sulfonamides
Signs & symptoms
3 Novemba 2020 12:34:48