Drug allergy and adverse drug reactions are common among many people. Those side affect of consuming drugs affecting an about 30% of hospitalized patients. Unintended and undesired reactions of consuming drugs may be immunologic or non immunologic nature. The latter let in drug toxicity, side effects, food intolerance symptoms, and idiosyncratic reactions, popular known as drug allergy.
Immunologic drug reactions or drug allergy are come as result from the specific fundamental interaction of a drug or one of its metabolites with disseminating IgG or IgM antibody, IgE antibody bound to mast cells or basophils, or sensitized lymphocytes. The resulting allergic reaction makes up the clinical reflections of the inflammatory reaction.
Allergic reaction and autoimmunity is a form of immune system response to an unrecognized substance exist or entering the body. Human’s body immune system attempts to repel these foreign substances by triggering antibodies and histamines into the body. This flooding of the body with unneeded disease-fighting mechanisms prodding’s a number of dissimilar responses in body.
Immunogenicity of a drug is related to both genetic factors and physical characteristics of the antigen (drug) itself. High-molecular-weight drugs (eg, insulin, heparin, and heterologous or animal proteins) are immunogenic without modification, but most drugs (eg, penicillin, sulfonamides, and phenytoin) are low-molecular-weight compounds that are not antigenic unless modified through a process called haptenation. In this case a drug or its metabolite forms acyl-, amide- or disulfide-bonds (or rarely noncovalent bonds) with the patient’s cell surfaces, soluble proteins, and other molecules with free amino or sulfhydryl groups.
The resulting complex or haptenated drug allergy is then recognized as foreign by the natural immune system and capable of inducing an immunologic response. Because many drugs are not chemically reactive in their native state, biotransformation or hydrolysis during metabolism is responsible for generating reactive compounds, that is, haptens. A full understanding of the immunochemistry of a low-molecular-weight drug is necessary to develop diagnostic drug allergy testing.
Taking medical drugs are far from safe for some groups of people. There are often drugs adverse reactions in the body linked with taking medical drugs. If you take or intend to take medically prescribed drugs you need to be aware of the possible for drugs adverse reactions in your body. Many people consider that taking medical drugs is the only choice to alleviate their disease problem. However, this is not the case and there are a broad range of good alternatives that do not have the adverse reactions like many medical drugs.
Drug-related risk factors for drug allergy are reflected in the prevalence of clinical drug sensitivity. Penicillin and other β-lactam antibiotics cause drug hypersensitivity in approximately 2 t 3% of the population by several different pathogenetic mechanisms. Therapeutic heterologous serum, such as antivenin and antithymocyte globulin, carry a high prevalence of immunopathologic reactions.
The route of administration and pattern of exposure can also determine sensitization, which is more likely to take place after topical exposure. High-dose intravenous therapy is more immunogenic than oral or brief courses of treatment. Antihistamines, for example, rarely cause allergic reactions when taken systemically, but frequently sensitize for allergic contact dermatitis when used topically, probably because of the highly proficient antigen-presenting Langerhans’ cells in the skin.
Patient-related risk factors are both genetic and acquired. Surprisingly, atopic status does not increase the risk of immediate drug sensitivity, but a familial propensity to develop drug allergy has been reported. Genetic factors allergy metabolism, and certain human leukocyte antigen (HLA) phenotypes have been linked to increased adverse drugs reactions reactivity. Genetic or acquired differences in N-acetylation rate (acetylation phenotype) or N-oxidation rate affect the risk for reaction to sulfonamides, hydralazine, and procainamide.
Concurrent disease or concomitant drug administration also affects the risk of reaction. Epstein-Barr virus and human immunodeficiency virus (HIV) infection significantly increase the risk of cutaneous reactions to ampicillin and sulfonamides, respectively. Despite the lack of CD4 helper lymphocytes in acquired immunodeficiency disease, there is evidence that immunoreactive CD8 cytotoxic cells can produce the cytokines that enhance IgE production, eosinophilia, or cell-mediated drug-induced immunopathology. The spectrum of frequent drug-induced reactions in HIV infection includes fever, rash, anaphylaxis, Stevens-Johnson syndrome, toxic epidermal necrolysis, and hematologic and hepatic reactions.©
