20 - ADRs Flashcards
List some reasons why ADRs occur (5 total)
- Can interact w/ other drugs
- Not all is known about safety of drug when marketed
- Misuse
- Patient factors
- Pharmaceutical factors
What makes someone susceptible to ADRs? (6 total)
- Polypharmacy
- Age (very young or very old)
- Gender
- Concurrent disease
- Genetics
- Allergy
1) Do natural health produces count as causing ADRs?
2) Does using at higher doses of a drug then normal count as an ADR?
1) Yes
2) No
Type A ADRs?
Augmented
- Predictable from pharmacology of medicine
- Dose-related
Type B ADRs?
Bizarre
- Not predictable from pharmacology
- Not dose related
- Less common than type A
Type C ADRs?
Chronic
- Following prolonged use
Type D ADRs?
Delayed
- Occurs remote in drug user or in offspring of user
Type E ADRs?
End of treatment
- When withdrawing treatment
Type F ADRs?
Failure
- Lack of efficacy of drug
Type G ADRs?
Genetic
- Genetic susceptibility
Problems with the current classification for ADRs?
- All ADRs are dose-related to some degree
- Genetic susceptibility is important in all types (more or less)
- Overlap in categories e.g. type A + type C/D/E
1) Drugs can interact w/…
2) Drug interactions can either be…
1) Drug-drug/NHP/food/drink/device/environmental agent
2) Pharmacokinetic (affects it’s ADME) or pharmacodynamic.
Best place to check for drug interactions?
- What about for UoA?
NZ formulary
- Stockley’s Drug Interactions is a reference for a bunch of drug interactions.
How can drug interactions affect absorption?
Since most drugs given orally, have to go through GI tract.
Interactions can affect:
- Rate of drug absorption
- Amount of drug absorbed
This can be due to:
- pH changes
- Absorption, chelation, and other complex stuff e.g. antacids absorb onto other drugs.
- Motility changes
- Induction/inhibitoon of drug transporter proteins.
How can drug interactions affect distribution?
Plasma-protein binding can be competed against and displace each other.
In practice, few clinically relevant interactions occur.
