adverse drug reactions Flashcards
Therapeutic Goods Administration (TGA)
Regulatory authority for therapeutic goods and maintains the Australian Register of Therapeutic Goods (ARTG)
TGA carries out assessment and monitoring of therapeutic goods in Australia
Evaluate and regulate therapeutics BEFORE they reach the market
Monitor therapeutics AFTER the reach the market
Regulatory decisions are made based on risk-benefit analyses
registered vs listed medicines
registered with higher risk when the benefits of taking the medicine outweight the risk
listed products with lower risk including vitamins minerals and complementary medicines
registered vs listed medicines
registered with higher risk when the benefits of taking the medicine outweight the risk
listed products with lower risk including vitamins minerals and complementary medicines
registered vs listed medicines
registered with higher risk when the benefits of taking the medicine outweight the risk
listed products with lower risk including vitamins minerals and complementary medicines
Post-Marketing Surveillance/Pharmacovigilence
Once on the market, the TGA continues to monitor safety and efficacy (performance). Post-marking surveillance is phase IV of a clinical trial.
what is required in an ADR report
Contact details for the reporter
Patient identifier (e.g., initials, DOB – NOT their full name)
Product details (now includes a tab for vaccines)
Description of the suspected ADR
Characterisation of Adverse Drug Reactions
A
Augmented
B Bizarre
C
Chronic
D
Delayed
E
End of Use (Withdrawal)
F
Failure
type A
augmented
common and predictable
dose relgaed
digoxin toxicity
type B
bizzare
uncommon
not related to pharmological action
unpredicable
• Examples o Immunological reaction o Malignant hyperthermia • Management o Withhold treatment o Avoid in future
- Allergic
- Rashes
- Serious reaction eg anaphylaxis
- Penicillin most common cause
- Allergic or hypernsensitive reacitons are immunological response
- These response cause inflammation and subsequent damage
- Hypersensitivity reaction
type C
chronic • Uncommon • Related to cumulative dose o ICS induced adrenal suppression o NSAIS and peptic ulcer o Bisphosphates ostecrosis • Reduced dose or withdrawl or a period of time
Type D
delayed • Uncommon • Usually dose related • Occurs or becomes apparent some time after using drug • Ex o Teratogenesis
type E
- After withdrawl
- Opiod withdrawal
- Beta blocker withdrawal
- Withdrawal very slowly
end of use
Type F
- Common
- Dose related
- Often caused by drug interaction
- Oral contraceptive failure
- Increase dosage
- Consider effects of concomitant therapy
Factors FOR ADR
- Age
- Sex
- Genetics
- Polypharmacy drug interactions
Not all ADRs fit into these categories
Eg metabolism of alchol
Rapidly absorbed
90% metabolized
5-10 percent expelled
type A digoxin toxicity
• Heart failure?af lecture
• Cardiac glycoside used in the treatment of HF last line and cardiac dysrhythmias
• Narrow therapeutic range
• Adverse effects are related to its plasma concentration
• Low therapeutic index
o Aka low therapeutic range
o Relationship between efficacy and safety
o Determining TI can be complex and depends on the stage of drug development
o A high therapeutic index is desirable a low index means adverse effects can occur
Type A diogixn toxcitiy
• MOA
o Afib slows HR and reduce AV nodal conduction by an increase in vagal tone and a reduction in SNS activity at higher dose can lead to AV node block
o HF: increases the force of myocardial contraction by increasing the release and availability of stored intracellular calcium
o Rate control by slowing the conduction rate of av node and increasing refractory period of av node
o Can be achieved with meds lf atenolol digoxin verapamil
• Inhibits NA/K pump
o Increase intracellular NA
o An increased intracellular concentration of NA reduces the efflux of CA from the cell which normally occurs via the NA/Ca pump
o This results
• Pharmacokinetics
o IV or oral
o Absorbed in stomach
o Majority eliminated unchanged via kidney
Substrate of p glycoprotein
