Adverse Drug Reactions Flashcards
Define: adverse drug reaction
An ADR is an unwanted or harmful reaction experienced following the administration of a drug or a combination of drugs, and is suspected to be related to the drug
Define: side effect
A side effect is a result of drug or other therapy in addition to or in extension of the desired therapeutic effect; usually but not necessarily, connoting an undesirable effect.
What are the the two types of ADRs?
Type A and type B
Outline the characteristics of type A Adverse drug reactions. (6)
1) pharmacology: augmented
2) predictable: yes
3) dose-dependent : yes
4) morbidity : high
5) mortality : low
6) management : dose reduction
- 80-90% of adverse drug reactions
Outline the characteristics of type B adverse drug reactions (5)
1) pharmacology: idiosyncratic or allergic
2) predictable: no
3) dose-dependent: no
4) morbidity: high
5) management: stop drug
Outline the importance of ADRs (3)
ADRs are common:
- 6.5% of hospital admissions were related to ADRs
- projected annual cost to the NHS of £466m
- over 2% patients admitted with an ADR died, suggesting an overall fatality rate from ADRs within the population of 0.15%
Are ADRs avoidable? (4)
- 72% hospital admissions due to ADRs were definitely or possibly avoidable
- obvious interactions
- use of contra-indicated drugs
- drugs use in an inappropriate clinical indication or medically unnecessary
Describe the pharmacists role in managing ADRs (6)
1) identify patients at risk of ADRs
2) identify drugs known to produce ADR and monitor patient appropriately
3) avoid use of drugs causing ADR where an equally effective and safer alternative exists
4) review patients medicines: stop unnecessary medicines, check for interactions and contraindications
5) ensure patient are counselled on the correct use of their medicines and possible side effects
6) report ADRs
Identify patients at risk of ADRs
1) extremes of age
2) females > males
3) polypharmacy
4) incurrent diseases
5) a history of intolerance or hypersensitivity
List the top 10 drugs known to produce ADRs (10)
1) NSAIDs
2) diuretics
3) warfarin
4) ACEIs/A2RAs
5) Antidepressants and lithium
6) beta-blockers
7) opioids
8) digoxin
9) perdnisolone
10) clopidogrel
What are the 5ways the BNF classifies side effects (5)
1) very common : greater than 1-10
2) common : 1 in 100 to 1 in 10
3) uncommon/ less commonly: 1 in 1000 to 1 in 100
4) rare : 1 in 10000 to 1 in 1000
5) very rare : less than 1 in 10000
Explain how you would counsel patients on side effects. (3)
- after you have dispensed a prescription you need to counsel a patient on the side effects
1) find the information on the BNF , patient information leaflet
2) only list the serious and common side effects
3) the most important ones are the serious ones - counsel the patient without scaring them
Before a new medicine is marketed , how many patients will have been treated with it?
1500- normal healthy individual
Which reactions are likely to have been picked up form animal studies during clinical trials? (3)
1) diarrhoea
2) dry mouth
3) liver toxicity
Explain why ADRs should be reported (3)
1) important mechanism for post-marketing surveillance of medicines
- limited drug safety information collected from clinical trials
- identify side-effects which may occur after long term use
2) vital for maintaining drug safety
3) professional responsibility to maintain patient safety