Week 4 Flashcards
What are the benefits/dangers of increasing drug concentration above 80% max response?
Little therapeutic effect
Significantly increases risk of adverse reactions
What is an adverse drug event?
‘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
What are the 6 Types/classification of Adverse Drug Reactions?
Type A (augmented) • Type B (bizarre) • Type C (continuous) • Type D (delayed) • Type E (end of use) • Type F (failure)
What happens when a drug concentration goes above 80%?
Achieves little therapeutic effect but significantly increases the risk of adverse reactions
What are the phases of drug discovery?
- Drug discovery
- Preclinical development
- Clinical development
- > phase 1 - PK tolerability, side effects in volunteers
- > phase 2 - small scale trials in patients
- > Phase 3 - large scale clinical trials
- Regulatory Approval
- Phase IV - postmarketing surveillance
Define an adverse drug reaction
an adverse drug event occurs whilst a person is taking a drug but is not necessarily due to the drug (includes mistakes in administration, etc)
What can cause an adverse drug reaction?
- excess stimulation of one ‘type’ of receptor (with a highly selective drug)
OR
Following interactions with other receptors at higher concentrations
Adverse drug reaction identification process must include what?
- Timing (relationship between the use of the drug and the occurrence of ADR)
- Pattern recognition (may fit the known pharmacology of one of the suspected drugs or a chemically related compound)
- Investigations (plasma, biopsies, allergy testing)
Explain Type A classifications
Type A = Augmented
- most common (approx 80% of ADR’s)
- typically predictable from known pharmacology
- Usually mild with high morbidity and low mortality
- able to be repoduced in animal studies
What’s an example of Type A classification ADR’s
Hypoglycaemia due to insulin injection
Explain Type B classifications
Type B = Bizarre
- uncommon - 20%
- unpredictable
- not related to a known pharmacological action of drug
- high morbidity low mortality
- lack of reproducibility in animal studies
Example of type B classified ADR
Anaphylaxis due to penicillin
Can repeat exposure lead to an increase in hypersensitivity severity?
yes
Explain type C classification in ADR
Type C = Chronic
- uncommon
- related to cumulative dose
Example of type c classified ADR
- colonic dysfunction due to laxatives
Explain type D classification in ADR
Type D - Delayed
- uncommon
- usually dose related
- occurs some time after the use of the drug
Explain type E classification in ADR
Type E - end use withdrawl
- uncommon
Example of type E classified ADR
opioid withdrawal
Explain type F classification in ADR
Type F - Failure of therapy
- becoming more common
- unexpected nil response in the setting of appropriate dose related regime
Example of type F classified ADR
resistance to antimicrobials
- superbug type shit
What are the risk factors for development of ADR?
- age
- gender
- concurrent diseases
- genetic factors
- history of prior drug reaction
- chemical characteristics
- route of administration
- dose
- duration and frequency
- polypharmacy
What does risk v benefit mean?
acceptable risk must be weighed against its potential therapeutic benefit
What are the variables influencing risk v benefit for drugs?
- dose administered
- patient
- route of administration
- time administered
what is a drug indication?
an illness or disorder for which a drug has a documented specific usefulness
