Wk2- Adverse Drug Reactions Flashcards
What is the definition of an ‘Adverse Drug Reaction’?
1- Lecture Definition 1- ‘any response to a drug which is noxious, unintended, and which occurs at doses normally (and appropriately) used in man for the prophylaxis, diagnosis, or therapy of a disease’
#2- Lecture Definition 2- ‘an appreciably harmful or unpleasant reaction, resulting from an intervention related to the use of a medicinal product, which predicts hazard from future administration and warrants prevention or specific treatment, or alteration of the dosage regime, or withdrawal of the product’.
Are the ‘side effects’ of a drug always detrimental to patients?
No- side effects can sometimes be beneficial. Just because we administer a drug for a specific effect mean that the drug doesn’t naturally have other effects within the body [eg. mirtazipine used in anorexic patients to cause weight gain. Antihistamines cause sedation & drowsiness so are used to aid sleep]
There are SIX (6) Classifications of Adverse Drug Reactions (ADRs)- Identify the name of each
Classifications of ADVERSE DRUG REACTIONS [ADRs]-
1- Type A- Augmented
2- Type B- Bizarre
3- Type C- Continuous
4- Type D- Delayed
5- Type E- End of Use
6- Type F- Failure
Type A [Augmented] Adverse Drug Reactions are the most common type of ADRs. What % of ADRs are Type A?
[Note- Augmented ADRs result from an exaggeration of a drugs normal pharmacological actions]
Type A [Augmented] ADRs= account for 80% of ADRs
[Note- Augmented ADRs result from an exaggeration of a drugs normal pharmacological actions]
Are Type A [Augmented] Adverse Drug Reactions:
a) Predictable?
b) Unpredictable?
Why?
A) Type A [Augmented] Adverse Drug Reactions are PREDICTABLE from the known pharmacology of the drug & related dose. This is because Type A/ Augmented ADRs result from an exaggeration of a drugs normal pharmacological actions
Are Type A [Augmented] Adverse Drug Reactions usually:
a) Mild?
b) Severe?
Type A [Augmented] Adverse Drug Reactions are usually-
a) Mild
What is the general morbidity & mortality usually like for Type A [Augmented] Adverse Drug Reactions?
[Hint- high? low?]
Type A [Augmented] Adverse Drug Reactions are usually mild with:
- High Morbidity
- Low Mortality
[of those that experience a Type A ADR-high rates of sickness, low rates of death]
What are the FIVE (5) main factors that contribute to Type A [Augmented] Adverse Drug Reactions?
Type A [Augmented] Adverse Drug Reactions are usually caused by:
1- Dose
2- Variation in drug formulation
3- Pharmacokinetic variation
4- Pharmacodynamic variation
5- Drug interactions
What is a ‘TYPE A’ [Augmented] Adverse Drug Reaction?
‘TYPE A’ [Augmented] Adverse Drug Reactions results from an exaggeration of a drugs normal pharmacological actions. eg. respiratory depression from opioids, bleeding from warfarin
What is a ‘TYPE B’ [Bizarre] Adverse Drug Reaction?
‘TYPE B’ [Bizarre] Adverse Drug Reactions are a novel response which is not expected from the known pharmacological actions of the drug. They are immune related reactions, not related to dose. eg. anaphylaxis from penicillin, skin rash from antibiotics
What is a ‘TYPE C’ [Continuous] Adverse Drug Reaction?
‘TYPE C’ [Continuous] Adverse Drug Reactions are reactions that are chronic and persist long-term. eg. adrenal suppression from steroids
What is a ‘TYPE D’ [Delayed] Adverse Drug Reaction?
‘TYPE D’ [Delayed] Adverse Drug Reactions become apparent some time after the use of a medication. eg. dyskinesia from antipsychotics, or leukopenia from quetiapine
What is a ‘TYPE E’ [End of Use] Adverse Drug Reaction?
‘TYPE E’ [End of Use] Adverse Drug Reactions are withdrawal reactions. eg. anxiety from withdrawal of benzodiazepines, or seizures from withdrawal from epililum
What is a ‘TYPE F’ [Failure] Adverse Drug Reaction?
‘TYPE F’ [Failure] Adverse Drug Reactions occur due to unexpected failure of therapy. The drug undesirably increases/decreases in efficacy. eg. antibiotics not working due to resistance
What are some methods for limiting Adverse Drug Reactions? [Lecture lists 5 methods]
Methods for limiting Adverse Drug Reactions-
1. Be aware of vulnerable populations (elderly, children, pregnancy)
2. Seek alternatives to drug therapy (eg. exercise & diet for HTN, low fat diet for Dyslipidaemia, exercise & mindfulness for chronic pain)
3. Frequent medication reviews and simplified drug regimen
4. Careful selection of drugs to reduce adverse drug reactions
5. Use the lowest dose to achieve the desired effect
