adverse drug reactions Flashcards
define ADRs
unwanted or harmful reactions following the administration of drugs or combination of drugs under normal conditions of use and are suspected to be related to the drug. Has to be noxious and unintended .
define side effects
an unintended effect of a drug related to its pharmacological properties and can include unexpected benefits of treatment
are side effects and ADRs the same thing?
they can be
but side effects can be beneficial but ADRs are always unpleasant
what are the 3 possible effects of ADRs and side effects?
- toxic effects -
- collateral effects
- hyper-suscepatbiplity effects
what is meant by toxic effects? when do toxic effects occur?
occur when Above therapeutic range
eg. Patient has too high levels of drug, or drug excretion is impaired
what is meant by collateral effects? when do collateral effects occur?
when within Therapeutic range, ie. standard therapeutic doses
what is meant by Hyper-susceptibility effects? when do Hyper-susceptibility effects occur?
Below therapeutic range, haven’t taken enough to see the benefit expected, and then they have an ADR
Eg. anaphylaxis from a small dose of penicillin
risk factors for ADRs
PATIENT FACTORS
Gender - higher risk for women
Elderly
Neonates
Polypharmacy
Genetic predisposition
hypersensitivity/allergies
Hepatic or renal impairment
Adherence problems - when patient doesn’t follow dose correctly
risk factors for ADRs
DRUG FACTORS
If the drug has a steep dose-response curve
If the drug has a low therapeutic index - easy to reach toxic range
If the drug is known to commonly cause ADRs
risk factors for ADRs
PRESCRIBER FACTORS
Prescriber risks → doctor makes a mistake when prescribing
give 5 examples of causes of ADRs
- a contaminant in drug
- patient has receptor abnormality
- Abnormal biological system unmasked by drug
(Problem with patient that is unknown until the ADR highlights it ) - Immunological
eg. penicillin induced anaphylaxis - Drug-drug interactions
what are the different categories of time dependent reactions
- rapid reaction
- 1st dose
- early
- intermediate
- late
- delayed
give an example of a delayed ADR
thalidomide in pregnancy
give an example of a common ADR drug
beta blockers
antibiotics
NSAIDS
name the classification system for ADRs
Rawlins Thompson classification A-F
Augemented
Bizzare
Continous
Delayed
End of treatment
Failure of therapy
describe type A class of ADRs
Augmented
- an exaggeration of primary drug effect
- common
- dose dependent
- eg. bleeding with warfarin
describe type B class of ADRs
bizarre
- no predictable
- not dose dependent
- life threatnetning eg. anaphylaxis to penicillin
describe type C class of ADRs
continuous/chronic
- uncommon
- relative to cumulative dose and time
- eg. osteroperosis from long term steroid use
describe type D class of ADRs
delayed
- uncommon
- shows up after time
- eg. teratogenesis from thalidomide taken in first trimester
describe type E class of ADRs
End of treatment
- occurs after abrupt drug withdrawal
- eg. opiate withdrawals
describe type F class of ADRs
Failure of therapy
- common
-dose related - often caused by drug interactions
- eg. failure of oral contraceptive pill in presence of enzyme inducer medication
what is DoTS?
another way to classify ADRs. stands for:
dose relatedness
timing
susceptibility of patient - host factors?
give 3 signs that would cause you to suspect ADR?
Symptoms soon after a new drug is started
Symptoms after a dosage increase
Symptoms disappear when the drug is stopped
6 actions to take if ADR
Assess if urgent action required ABC
Take history
Review medication history
Review the adverse effect profile of suspected drug
Modify dose, stop or swap
Report
common ADR symptoms
Confusion
Nausea
Balance problems
Diarrhoea
Constipation
Hypotension
name the scheme that is used for reporting ADRs
the yellow card scheme - a voluntary reporting system of suspected ADRs
what are the 4 critical pieces of info to record on. a yellow card?
Suspected drug
Suspect reaction
Patient details
Reporter details
for which suspected reactions should you report for?
Report ALL suspected reactions for
Herbal medicines
Black triangle drugs
Report SERIOUS suspected reactions for
Established drugs, vaccines
Drug interactions
what are black triangle drugs?
medicine is undergoing additional monitoring
eg. it contains a new active substance, it has been given under exceptional circumstances
what does a serious reaction look like ?
Fatal,life threatening, disabling, incapacitating, results in hospitalisation, prolongs hospitalisation
who can report a yellow card?
Drs,dentists,coroners,pharmacists,nurses,midwives,health visitors, radiographers, optometrist, PATIENTS, and parents/carers of the patient
