Drug Therapy : Adverse Drug Reactions Flashcards
<p>What are adverse drug reactions?</p>
<p>Any response to a drug which is noxious, unintended and occurs at doses used in man for prophylaxis (treatment to prevent disease), diagnosis or treatment</p>
<p>What is prophylaxis?</p>
<p>Treatment to prevent disease</p>
<p>Adverse drug reactions are the what cause of death (number)?</p>
<p>4th leading cause of death</p>
<p>How much hospital admissions occur due to adverse drug reactions?</p>
<p>6.5%</p>
<p>How many inpatients suffer adverse drug reactions?</p>
<p>10-20%</p>
<p>What are the 3 classifications of the onset of adverse drug reactions?</p>
<p>Acute</p>
<p>Sub-acute</p>
<p>Latent</p>
<p>When do acute adverse drug reactions occur?</p>
<p>Within 60 seconds</p>
<p>What is an example of an acute adverse drug reaction?</p>
<p>Bronchoconstriction</p>
<p>When do sub-acute adverse drug reactions occur?</p>
<p>1 to 24 hours</p>
<p>What are examples of sub-acute adverse drug reactions?</p>
<p>Rash</p>
<p>Serum sickness</p>
<p>When do latent adverse drug reactions occur?</p>
<p>More than 2 days later</p>
<p>What is an example of a latent adverse drug reaction?</p>
<p>Eczematous eruptions</p>
<p>What are the 3 classifications of the severity of adverse drug reactions?</p>
<p>Mild</p>
<p>Moderate</p>
<p>Severe</p>
<p>What is a mild adverse drug reaction?</p>
<p>Bothersome but requires no change in therapy</p>
<p>What is an example of a mild adverse drug reaction?</p>
<p>Metallic taste with metronidazole</p>
<p>What is a moderate adverse drug reaction?</p>
<p>One which requires a change in therapy and some additional treatment</p>
<p>What is an example of a moderate adverse drug reaction?</p>
<p>Amphotericin induced hypokalaemia</p>
<p>What is a severe adverse drug reaction?</p>
<p>Disabling or life threatening</p>
<p>What is an example of a severe adverse drug reaction?</p>
<p>Kidney failure</p>
<p>What are the classifications of adverse drug reactions?</p>
<p>Type A (augmented)</p>
<p>Type B (bizarre)</p>
<p>Type C (chronic)</p>
<p>Type D (delayed)</p>
<p>Type E (end of treatment)</p>
<p>Type F (failure of treatment)</p>
<p>How can type A (augmented) drug reactions be described?</p>
<p>Dose related</p>
<p>Predictable</p>
<p>How can type B (bizarre) adverse drug reactions be described?</p>
<p>Idiopathic</p>
<p>Unpredictable</p>
<p>What are predisposing factors of adverse drug reactions?</p>
<p>Multiple drug therapy (incidents increase exponentially with the number of medicaments)</p>
<p>Inter-current disease (renal and hepatic impairments)</p>
<p>Race and genetic polymorphisms</p>
<p>Age (elderly and neonates)</p>
<p>Sex (more common in woman)</p>
<p>What does predisposing mean?</p>
<p>Make more liable</p>
What are some inter-current diseases that increases the risk of adverse drug reactions?
Renal and hepatic impairment
Who are more likely to experience adverse drug reactions out of men and woman?
Woman
What are type A (augmented) adverse drug reactions due to?
Excess pharmacological action
What are examples of excess pharmacological action that causes type A (augmented) adverse drug reactions?
Bradycardia with beta-blockers
Hypoglycaemia with insulin
What is the most common adverse reaction and what percentage of total reactions does this account for?
80% of adverse drug reactions are type A (augmented)
What are the 2 types of type A (augmented) adverse drug reactions?
Augmentation of the primary effect
Secondary effect
What are some common type A adverse reactions?
Galactorrhoea with domperidon
Dry mouth with tricylic antidepressants
Glynaecomastia with spironolactone
Bronchospasm with beta blockers
What could some reasons for type A (augmented) adverse drug reactions be?
Too high a dose
Pharmaceutical variation
Pharmacokinetic variation
Pharmacodynamic variation
What are examples of pharmacodynamic variations?
Variations in:
Dose
Distribution
Metabolism
Elimination
What is pharmacogenetics?
The study of inherited genetic differences in drug metabolic pathways
What are a number of drugs metabolised via, which is under genetic control?
Acetylation
What are people who are slow metabolisers of drugs prone to?
Drug toxicity
What diseases increase the likeliness of adverse drug reactions?
Renal and hepatic impairment
Cardiac failure
Why do renal and hepatic impairments increases the risk of adverse drug reactions?
Not excreted or metabolised so will build up and be toxic
Why does cardiac failure lead to increased risk of adverse drug reactions?
Reduced drug absorption from gut so it builds up and becomes toxic
What are most type A adverse drug reactions in nature?
Pharmacokinetic
What can you say about type B (bizarre) adverse drug reactions and dose?
Type B reactions are unrelated to dose
What can you say about the reversibility of type A and type B adverse drug reactions?
Type A are readilly reversible whereas type B are not
What are type B adverse drug reactions common with?
Macromolecules
Patients with a history of asthma
HLA status (presence of particular HLA increases risk)
What are some macromolecules associated with type B (bizarre) adverse drug reactions?
Proteins
Vaccines
Polypeptides
What are the 2 mechanisms of type B adverse drug reactions?
Idiosyncratic (peculiar, individual)
Drug allergy or hypersensitivity
What are idiosyncritic type B adverse drug reactions due to?
Genetic abnormality such as enzyme dificiency or abnormal receptor activity
What are the properties of hypersensitive type B adverse drug reactions?
No relation to the pharmacological action of the drug
Delay between exposure and adverse drug reaction
No dose response curve
What is pharmacodynamics?
Branch of pharmacology concerned with the effects of drugs and the mechanisms of their actions
What may a difference in the response to a drug, in terms of pharmogenetics, be considered as?
Genetic
Immunological
What are the kinds of genetic abnormalities that lead to unpredictable responses to drugs?
Enzyme abnormality
Receptor abnormality
What are type C (chronic) adverse drug reactions related to?
Duration of treatment as well as the dose
What do type C (chronic) adverse reactions not occur with?
A single dose
What are examples of type C adverse drug reactions?
Iatrogenic Cushings disease
Steroid induced osteoporosis
Opiate dependance
What are type D adverse drug reactions?
Delayed, occuring a long time after treatment
What are examples of type D (delayed) adversed drug reactions?
Teratogenesis
Carcinogenesis
What is an example of teratogenesis type D adverse drug reaction?
Craniofacial malformations in children whose mothers were treated with isotreoin
What is an example of carcinogenesis type D adverse drug reaction?
Second cancers in those treated with alkylating agens or immunosuppresive agents
What is teratogenesis?
Abnormal congenital malformations in the foetus following in utero exposure due to maternal medications use during 1st trimester of pregnancy
What are some teratogenic agents?
Cytotoxics
Vitamin A
Antithyroid drugs
Steroids
Oral anticoagulants
What drugs should be avoided during pregnancy?
All drugs unless they are safe or the benifits outweight the potential risks
What are type E adverse drug reactions?
Adverse effects that occur when a drug treatment is stopped especially suddenly following long term use
What are examples of things that can cause type E adverse drug reactions?
Unstable angina and MI when beta blockers are stopped
Addisonian crises when long term steroids are suddenly stopped
Withdrawal seizures when anti-epileptics are stopped
Alcohol
When does rebound phenomena occur?
When adverse drugs are suddenly withdrawn
What are some drugs that can cause a rebound phenomena?
Alcohol
Benzodiazepines
Beta blockers
Corticosteroids
What are type F adverse drug reactions?
A failure of therapy
What is the frequency of type F adverse drug reactions and what are they related to?
They are common and are dose related
What are type F adverse drug reactions often caused by?
Drug interactions
What is the process of diagnosing adverse drug reactions?
1) Differential diagnosis
2) Medication history (past and present)
3) Assess time of onset and dose relationship
4) Laboratory investigations (plasma concentration measurements and allergy tests)
What are laboratory tests used to diagnose adverse drug reactions?
Plasma concentration measurements
Allergy tests
Who are some people most at risk from adverse drug reactions?
Age (children and elderly)
Multiple medications
Multiple co-morbid conditions
Inappropriate prescribing, use, or monitoring
End-organ dysfunction
Altered physiology
Prior history of adverse drug reactions
Extent (dose) and duration of exposure
Genetic predisposition
What are some drugs commonly involved in adverse drug reactions?
Antibiotics
Antineoplastic
Anticoagulants
Cardiovascular drugs
Hypoglycaemic
Antihypertensive
NSAID/analgesics
Diagnostic agents
CNS drugs
Opiates
What are some body systems commonly involved in adverse drug reactions?
Haematologic
CNS
Dermatologic/Allergic
Metabolic
Cardiovascular
Gastrointestinal
Renal/genitourinary
Respiratory
Sensory
What can adverse drug reactions be reported to?
Yellow card scheme which collects information about:
Side effects
Medical device adverse incidents
Defective medicines
Counterfeit or fake medicines or medical devices
What does the yellow card scheme collect information about?
Side effects
Medical device adverse incidents
Defective medicines
Counterfeit or fake medicines or medical devices
