Adverse Drug Actions Flashcards
What is the difference between adverse drug reactions (ADR) vs adverse drug events (ADE)?
ADR is a type of ADE, which is caused by the appropriate usage of the drug. ADE is all other adverse effects too.
What are the mechanisms of drug hypersensitivity reactions? (Type I)
Drug-IgE complex binding to mast cells with release of histamine
What population is at risk for ADRs?
Pediatrics (New borns)
Geriatrics (>60 years)
Renal or hepatic impairment
Genetic variation
What is pharmacovigilance?
It is the study of drug-related injuries
What is the formula for therapeutic index (TI)?
TI = TD50 / ED50
What is ED50?
Dose produces specified “therapeutic effect” in 50% of animals tested
What is TD50?
Dose produces toxic/adverse effects in 50% of animals tested
What does lower TI usually mean?
There is a higher risk to develop side effects
What is Adverse drug reaction (ADR)?
Adverse drug reaction (ADR) refers to an unwanted/unintended and undesirable effect of a drug at doses normally used in man for therapy.
What is adverse drug event?
Adverse drug event (ADE) is an untoward medical occurrence of a drug which does not necessarily have a causal relationship with the treatment.
What is the different classifications of ADRs?
Type A (augmented)
Type B (Bizarre)
What is Type A ADRs?
It is an adverse reaction that is dose-dependent, predictable, low mortality
What is type B ADRs?
It is the bizarre adverse reaction that is dose-independent, unpredictable, high mortality, and unrelated to pharmacological action, hypersensitive (immunologic), idosyncratic - dont know why patient would behave this way until they take the drug
What are the type B hypersensitive classifications?
Type I (IgE-mediated)
Type II (cytotoxic)
Type III (immune complex)
Type IV (delayed, cell mediated)
Which immune cell is activated in idiosyncratic ADRs?
Mast cells
What are the additional classifications of ADRs?
Type C (chronic)
Type D (delayed)
Type E (end of dose) - withdrawal syndrome
What are the mechanisms of drug hypersensitivity reactions? (type II)
IgG or IgM directed at drug-hepten-coated cells
What are the mechanisms of drug hypersensitivity reactions? (type III)
Drug-antibody complex deposition with complement activation and inflammation
What are the mechanisms of drug hypersensitivity reactions? (type IV)
Drug molecule presentation to T cells with cytokine and mediator release
What are the symptoms of ADR hypersensitivity? (type I)
Urticaria, angiodema, pruritus, anaphylaxis
What are the symptoms of ADR hypersensitivity? (type II)
Hemolytic anemia, thrombocytopenia
What are the symptoms of ADR hypersensitivity? (type III)
Serum sickness, fever, rash, glomerulonephritis, vasculitis
What are the symptoms of ADR hypersensitivity? (type IV)
contact dermatitis, rash, stevens-johnson syndrome
What are the idiosyncratic ADR for opiates (morphine, codeine)
flushing, urticarialm, red man syndrome
What are the idiosyncratic ADR for halothane?
malignant hyperthermia
What are the idiosyncratic ADR for anti-malarial drug primaquine?
Hemolytic anemia in glucose-6-phosphate dehydrogenase (G6PD)-deficient patients
