Adverse drug reactions (ADR) Flashcards
What is an adverse drug reaction?
An unwanted or harmful effect after administrating a drug.
Why are ADRs important?
they are common? 1in 16 hospital admissions
harmful? 2% of patients admitted die
due to effects on the patient? most common GI Bleed /NSAID
avoidable?
cost?
What are the Cause of ADR
TRIP
T- TIME time between taking the drug and the reaction
R- RECOVERY- recovery once problem corrected
I- Independant evidence e.g blood test
P- PREDICTABLE- has been reported before
What are ADRs not?
Medication errors
Name they main type of ADRs?
Type A and Type B.
What are type A ADRs?
Common and dose-related – constipation with opioids, sedation with antihistamines.
Excessive pharmacological effect
Withdrawal and rebound responses
What are type B ADRs
Bizarre – unrelated to pharmacology
Infrequent and not necessarily dose-related
Allergic responses (hypersensitivity)
E.g. Anaphylaxis with Penicillin
What are ARDs in older adults?
Age-related physiological changes,
diminished homeostatic reserves -
Changes in fat and water distribution
Hepatic and renal impairment.
Complications of long-term conditions,
multiple pathologies
Polypharmacy
What are ADR’s in Children
Renal and hepatic function not mature or at full capacity
Less likely to have been exposed to clinical trials
Drugs used to treat children are not necessarily licensed in this age group
What are ADR’s in Pregnant women
Changes to the distribution of drugs (placental barrier, blood-brain barrier)
Teratogenic – impact on the development of the foetus
Unpredictable disease progression
Less likely to have been exposed to clinical trials
What are high risk ADR medications?
Methotrexate, Warfarin, NSAIDS, digoxin opioids, acetyl salicylic acid (aspirin) and beta-blockers.
47% of all medical incidents caused by these 7
What to do about ADRs?
What is responsible? (how to find out?)
Stop the drug or reduce the dose.
Treat the symptoms if necessary.
Prescribe an alternative (beware: cross-sensitivity).
Inform patient, and document in patient’s notes.
What is the yellow card scheme?
started in 1964 after the thalidomide tragedy Medicines and Healthcare products Regulatory Agency (MHRA) introduced the yellow card scheme to
report adverse reactions
side effects
vaccine safety
device problems
