Adverse Drug Reactions Flashcards
What is an adverse drug reaction?
Any response to a drug which is noxious, unintended and occurs at doses used in man.
How many ADR admissions are there every year?
1,000,000
What is an acute onset?
Within 60 minutes
Bronchoconstriction
What is a subacute onset?
1-24 hours
Rash, serum sickness
What is a latent onset?
2 days
Eczematous eruptions
What are the 3 severities of reactions?
Mild
Moderate
Severe
What are the classifications of ADRs?
A - Augmented B - Bizarra C - Chronic D - Delayed E - End of treatment F - Failure of treatment
Explain Type A.
Dose related
Predictable
Explain Type B.
Idiosyncratic and unpredictable.
What are the predisposing factors of ADRs?
Multiple drug therapy
Age
Sex
Are Type A reversible?
Yes
What % of ADRs are Type A?
80
What are the 2 types of type A?
Augmentation of primary effect
Secondary effect
What are the 4 reasons for Type A ADRs?
High dose
Pharmaceutical variation
Pharmacokinetic Variation
Pharmacodynamic variation
What can cause pharmacokinetic variation?
Absorption Distribution Metabolism Liver disease Elimination
What can cause pharmacokinetic variation?
Absorption Distribution Metabolism Liver disease Elimination
What is a pharmacogenetic drug?
Metabolised via acetylation which is under genetic control.
What are two types of disease?
Renal and hepatic
Cardiac failure
What are the pharmacodynamic variations?
Natural variability
Disease states can alter
What are the features of Type B ADRS?
Bizarre Unpredictable Rare Serious illness/Death Unidentified Unrelated to dose
What is the mechanism of Type B ADRs?
Immunological
no relation, delay between exposure, no dose, manifests as rash
What are Type B more common with?
Macromolecules
Patients with asthma, eczema
What are idiosyncratic reactions?
Inherent abnormal
What are the two genetic abnormalities?
Enzyme
Receptor
What are drug allergies also called?
Hypersensitivity reactions
What are features of type C reactions?
Semi-predictable
Iatrogenic cushing’s disease
Steroid induced osteoporosis
Opiate dependence
What are the features of Type D effects?
Occur long time after treatment
Teratogenesis
Carcinogenesis
Children of treated patients
What cancers can Type D effects be seen in?
Second, treated with alkylating agents.
What are some teratogenic agents?
Cytotoxics
Vit A
Antithyroid drugs
Steroids
What are the features of Type E treatments?
Occur when a drug treatment is stopped especially suddenly.
What happens when anti-epileptics are stopped?
Withdrawal seizures.
What happens when anti-epileptics are stopped?
Withdrawal seizures.
When does rebound phenomena occur?
When a drug is suddenly withdrawn.
What are the features of Type F ADRs?
Common
Dose related
Frequently caused by drugs
Seen in children with too low doses
What are the 4 steps of diagnosis in ADRs?
Differential diagnosis
Medication history
Time of onset and dose
Lab investigations
How do you report ADRs?
Yellow card scheme
