Chapter 5 Flashcards
how many serious adverse drug reactions are reported annually
660,000 that result in ED visits, hospital admissions and 120,000 reported deaths.
total cost associated with ADR
3.5 billion to 126 billion per year
ADR
any undesirable or unintented effect after administration of a medical product, whter or not the effect is considered related to amedical product.
Two basic types of ADRs
phamacological and idiosyncratic
phamacological reaction
predictable baed on the drug’s MOA and is typically dose realted
Idosyncratic reaction sare
unpredictable and may more lkely to result in moretality
which type of reaction is more common
pharmacological
Example of a pharmacological reaction
hypotention from a beta blocker, diarrhea from the fat-blocking drog orlistat, and insomnia from the stimulat methylphenidate. Seondary effects are included such as weight gain from atypical antipsycotics.
Idiosyncratic reactions are
unpredictable, often serious and may result in death.
Idiosyncratic reactions are mediated
mediated by the immune syste, receptor abnormaliteis, dug-durg-intractions, abnormailites in metabolisy, pharmaceutical variations or unmasking of abnormal biogical sytms.
Hapten hypothesis
describes how drugs may cause an immune-mediated hypersensitivety reaction. The hypotheis suggests taht drugs are haptens, which are low-molecular weight chemcicals that can become antigenic when they covalently bind to a carrier molecule, usually a protein. Through this mechanism, individual patterns of metabolism may generat reactive metabolites that act as haptens to elicit an immune medicate reaction. Penicillin is an example of a haptin with low molecular weight that is able to bind to a protein and result in type I sensivity reaction.
Medicatoins that rae not haptens may also eliciit an immune-medicate raction through a different mechanism called the
pharmacologic interaction with immune receptors
an example of a phmacologic interaction with immune receptors
licocain, sulfamethoxazole, mepivacaine, celecoxib, carbamazepine, lamotrigine, and ciprofloxacin are chemcically inert drugs, unable to covalently bind to protins, howevier if amedication or its metabolite is able to bind covalently to a protein, it can form hapten-carrier complex and resutl in an immune response.
These hapten carrier complexes that restul in immune mediate reactions are called
type I, II, III, or IV
Type one are provoked by
exposure to an antigen
type one reaction is an
acute hypersensitivety reaction that may be local or systemic involving the skin, or bronchpulmonary system, nasopharngeal tract, eyes and GI tract
Typ one is caused by inducing the release of
mediators (histimine, leukotrienes and prosagrandins from mast cells, basophils, and recruited inflammatory cells after antigen exposure which then activates IGE.
Type one reactions vary from mild to severe and can come one
within minutes or have delayed onset where it takes severl hours to present symptoms. can be life threatenting.
Type one basics and examples
immunoglobulin E mediated, immediate type hpersensitivty. Eample angioedema and anaphylaxis
Type two basics and examples
antibody-dependent cytotoxicity, example heparin-induced thrombocytopenia
type three basics and examples
immune complex hypersensitivity, example arthus reaction to tetanus vaccine
type four basics and examples
cell mediated or delayed hypersensitivty, example, drug rash eosinophilia, and systemic syndrome (DRESS)
Type two hypersensitivy reactions may affect a variety of organs and tissues. In the bloodstreat
and on the surface of cells, antibodies unite with antigens or hapttens and induse destrcution of cells and tissues throguh activatio nof complent systems or through removal by macrophages.
hapetns
a small molecule which, when combined with a larger carrier such as a protein, can elicit the production of antibodies which bind specifically to it (in the free or combined state).
