Adverse Drug Reactions Flashcards
What is the difference between Adverse Drug Reactions (ADRs) and Adverse Drug Events (ADEs)?
ADRs are unwanted effects directly attributed to a drug, while ADEs are untoward medical occurrences that do not necessarily have a causal relationship with the drug treatment.
What are the two main classifications of Adverse Drug Reactions (ADRs)?
Type A (Augmented) and Type B (Bizarre)
Define Therapeutic Index (TI).
TI = TD50 / ED50
What does ED50 represent?
Dose that produces a specified therapeutic effect in 50% of animal tested.
What does TD50 represent?
Dose that produces toxic/adverse effect in 50% of animal tested.
True or False: The term ‘Adverse Drug Reaction’ is preferred over ‘Side Effect’.
True
What is a contraindication?
A specific situation in which a drug should NOT be used because it may be harmful.
What is a special precaution?
A condition that may increase the risk of an adverse reaction.
How does the WHO define an Adverse Drug Reaction (ADR)?
An unwanted, unintended, and undesirable effect of a drug at normal therapeutic doses.
List three facts about Adverse Drug Reactions (ADRs).
- Occur almost daily in healthcare institutions
- Account for at least 5% of all hospital admissions
- Cause morbidity and mortality
What percentage of hospital admissions in the USA is attributed to ADRs?
30%
What is the mortality rate of serious ADRs in inpatients?
0.1%-0.3%
What are the characteristics of Type A ADRs?
- Common (~80%)
- Dose-dependent
- Predictable
- Low mortality
What are the characteristics of Type B ADRs?
- Uncommon (~10%)
- Dose-independent
- Unpredictable
- High mortality
Fill in the blank: Type A ADRs are pharmacologically ______.
predictable
What is the mechanism behind Type I hypersensitivity reactions?
IgE-mediated drug-IgE complex binding to mast cells with release of histamine.
What is an example of a Type II hypersensitivity reaction?
Hemolytic anemia or thrombocytopenia.
What is a common clinical manifestation of Type III hypersensitivity reactions?
Serum sickness, fever, rash.
What is the timing of reactions for Type IV hypersensitivity?
2-7 days after cutaneous exposure.
What are idiosyncratic ADRs?
ADRs resembling immediate hypersensitivity reactions but not mediated by allergen-IgE interaction.
What are Type C ADRs related to?
Both dose and time.
What is the definition of Pharmacovigilance?
Study of drug-related injuries encompassing detection, assessment, understanding, reporting, and prevention of ADRs.
What populations are at greatest risk for ADRs?
- Pediatrics
- Geriatrics
- Individuals with renal or hepatic impairment
- Those with genetic variations
What is the role of HLA-B*5701?
It is associated with Abacavir hypersensitivity.
Fill in the blank: Successful pharmacovigilance involves communication of patterns and trends of suspected ______.
ADRs
What is the expected outcome of successful pharmacovigilance?
Preserving the safety and quality of life for patients.
