Bulletin (July - September 1998 Vol.6 No.3)
ทบาทของ Reactive Drug Metabolites ต่อการเกิดอาการไม่พึงประสงค์จากการใช้ยา
ตารางที่ 2 แสดงการแบ่งประเภท ADR ชนิดที่คาดการณ์ได้ และชนิดที่คาดการณ์ไม่ได้
| Predictable (dose-dependent) | |
| Overdose | Toxic reaction to specific organ systems due to excessive dose or impaired excretion เช่น gentamicin overdose produce ototoxicity and nephrotoxicity |
| Adverse effects | Undesirable pharmacologic effects by mechanisms related to the desired effects เช่น beta-2 agonists produce fine tremorr in plasma treatment |
| Interactions drug-drug | Action of the drug on the effectiveness or toxicity of another drug เช่น cimetidine inhibits cytochrome P450 metabolism of phenytoin, causing decrease phenytoin clearance and exaggerated effects |
| Interactions drug-disease | When taken concomittantly certain disease processes interfere with drug metabolism or action เช่น high incidence of rash when amoxicillin is used to infectious mononucleosis |
| Unpredictable (dose-independent) | |
| Intolerance | Exaggerated, often disabling effects when medications are given in usual dose เช่น extreme nausea and vomiting in erytromycin recipients and therapeutic doses |
| Idiosyncrasy | Genetically determined abnormal reaction to drug related to metabolic or enzyme deficiency, or altered activation/ detoxification pathways เช่น glucose-6- phosphate dehydrogenase deficiency induced hemolysis with primaquine |
| Allergy | Severe, recurrent, immunologically mediated reactions specific to a given agents เช่น b-lactam antibiotic anaphylaxis due to an immune response to hapten formation |
| Pseudoallergy |
Clinical similar to allergic reactions but involve an unknown immune mechanism เช่น directed mediator release by NSAIDs but causing angioedema, urticaria,and bronchospasm |