ADRs

Question 1

What is an adverse drug reaction?

Answer 1

unwanted or harmful reaction following administration of a drug or combination of drugs under normal conditions of use and is suspected to be related to the drug

Question 2

give examples of mild ADRs

Answer 2

nausea
rash
drowsiness

Question 3

give examples of serious ADRs

Answer 3

respiratory depression
neutropenia
catastrophic haemorrhage
anaphylaxis

Question 4

Why are ADRs important?

Answer 4

5th commonest cause of hospital death
majority are preventable
affects pt's quality of life
pts lose confidence in their doctors 
increases cost of pt care
prevent drugs being used in pts
may mimic disease 
cause hospital admissions

Question 5

What is the Rawlins Thompson classification?

Answer 5

Augmented
Bizarre/idiosyncratic
Chronic
Delayed
End of treatment

Question 6

What are the causes of ADRs?

Answer 6

pharmaceutical variation
receptor abnormality 
abnormal biological system unmasked by a drug
abnormalities in drug metabolism
immunological
drug to drug interactions 
multifactorial

Question 7

Explain what an augmented drug reaction is

Answer 7

predictable
dose dependent
common
extension of primary effect or a secondary effect of the drug

Question 8

Give examples of an augmented drug reaction

Answer 8

bradycardia and propanolol
hypoglycaemia and insulin
haemorrhage and anticoagulants
secondary effect - bronchospasm with beta blockers

Question 9

Explain what a bizarre reaction is

Answer 9

not predictable
not dose dependent 
cannot be readily reversed
less common but often serious
can be either idiosyncrasy or allergy/anaphylaxis

Question 10

Give examples of bizarre reactions

Answer 10

penicillin and anaphylaxis

Question 11

What is idiosyncrasy?

Answer 11

inherent abnormal response to a drug

Question 12

Give examples of types of iodiosyncrasy

Answer 12

enzyme deficiency

receptor abnormality

Question 13

Give an example of an enzyme deficiency that causes an idiosyncratic reaction

Answer 13

haemolysis with primaquine

due to G6PD deficiency (glucose 6 phosphate dehydrogenase)

Question 14

Give an example of a receptor abnormality that causes an idiosyncratic reaction

Answer 14

malignant hyperpyrexia with GA

this is a drastic and sustained rise in body temperature

Question 15

Explain how allergy to a drug develops

Answer 15

first dose acts as an antigen
then Ab is produced
second dose is an Ag-Ab reaction

Question 16

What are the types of hypersensitivity reaction?

Answer 16

type 1 - immediate anaphylactic IgE mediated
type 2 - Cytotoxic, antibody-dependent IgM or IgG (Complement) MAC
type 3 - Immune complex disease
type 4 - delayed hypersensitivity T cell mediated

Question 17

Give examples of a chronic type ADR

Answer 17

steroids and osteoporosis
analgesic nephropathy
steroids an iatrogenic Cushings syndrome
colonic dysfunction due to laxatives

Question 18

Give examples of delayed ADRs

Answer 18

teratogensis - eg drugs taken in the first trimester - thalidomide
carcinogenesis - cyclophosphamide (chemo and immunosupressant) can cause bladder cancer

Question 19

Give an example of end treatment ADRs

Answer 19

abrupt withdrawal of glucocorticoids leads to adrenocortical insufficiency
withdrawal seizures when anti-convulsants are stopped

Question 20

What are the pt risk factors for ADRs?

Answer 20

gender (W>M)
elderly
neonates
polypharmacy
genetic predisposition
hypersensitivity/allergies
hepatic/ renal impairment
adherence problems

Question 21

What are the drug risk factors for ADRs?

Answer 21

steep-dose response curve

low therapeutic index

Question 22

Give examples of prescriber risks for ADRs

Answer 22

prescription errors
erroneous medical decisions
ommissions in the prescription
poor handwriting
inadequate knowledge
inadequate communication between HCWs

Question 23

What are the suggestions that an ADR is occurring?

Answer 23

symptoms soon after a new drug is started
symptoms after a dosage increase
symptoms disappear when the drug is stopped
symptoms reappear when the drug is restated

Question 24

What are the most common drugs to have ADRs?

Answer 24

antibiotics eg penicillin
anti-neoplastics
cardiovascular drugs 
hypoglycaemics eg insulin
NSAIDs
CNS drugs

Question 25

What are the most common systems to be affected by an ADR?

Answer 25

``` GI Renal Haemorrhagic metabolic endocrine dermatological ```

Question 26

What are common drug reactions?

Answer 26

``` confusion diarrhoea nausea constipation balance problems hypotension ```

Question 27

How can ADRs be avoided?

Answer 27

give appropriate meds don't give unnecessary meds check for interactions report ADRs

Question 28

What does the Medicines and Healthcare products regulatory agency do?

Answer 28

1. approves medicines and devices for use 2. watches over the medicines and devices and takes actions eg drug withdrawal to protect the public if there is a problem

Question 29

What is the yellow card scheme?

Answer 29

ADR reporting scheme collects spontaneous reports collects suspected drug reactions voluntary reporting

Question 30

What are the strengths of the yellow card scheme?

Answer 30

Acts as an early warning system for identification of previously unrecognised ADRs provides info about which factors predispose to ADRs allows comparison of ADR profiles between products in the same therapeutic class, so could use another drug instead if found to be safer continual safety monitoring cheap to operate rapid readily accessible can be applied widely and throughout a drugs use

Question 31

What are the weaknesses of yellow card reporting?

Answer 31

cannot provide estimate of risk as number of cases is underestimated and total number of pts exposed is unknown ADR may not be recognised ADRs may not be reported reporting increases when there is a new drug and decreases over time

Question 32

Why are ADR reporting rates low?

Answer 32

- people not sure how to report - people don't want to be foolish as to incorrectly identifying an ADR - people do not want to expose themselves to legal liability/ don't want to admit harm caused - people too busy to report ADR - people believe that only safe drugs are used

Question 33

What does the code of practice say about recording ADRs?

Answer 33

1. Drs MUST report (inform MHRA) all suspected ADRs to medicines and products with a black triangle in the BNFusing the yellow card scheme 2. MUST inform MHRA about adverse incidents involving medical devices, incl. those caused by human error that put or have the potential to put the safety of pts and HCWs at risk 3. should provide pts with information about how they can report suspected side effects to the MHRA

Question 34

Why should we report ADRs?

Answer 34

important for pt safety to identify ADRs not identified in clinical trials to identify new ADRs to compare drugs in the same therapeutic class to identify ADRs in at risk groups

Question 35

What reactions should be reported on a yellow card?

Answer 35

all suspected reactions for herbal medicines AND black triangle drugs all serious suspected reactions for established drugs and vaccines

Question 36

What does the black triangle mean?

Answer 36

a medicine that is undergoing additional monitoring

Question 37

Give reasons as to why a drug may be undergoing additional monitoring

Answer 37

contains a new active substance is a biological medicine eg a vaccine or a medicine derived from plasma has been given conditional approval or only approved under certain circumstances the company is collecting data on the drug

Question 38

What is a serious reaction?

Answer 38

``` fatal life-threatening disabling or incapacitating results in hospitalisation prolongs hospitalisation ```

Question 39

Who can report on a yellow card?

Answer 39

``` doctors dentists coroners pharmacists nurses midwives health visitors radiographers optometrists pts and carers and parents ```

Question 40

What info should be included in a yellow card?

Answer 40

``` suspected drugs suspected reactions pt details reporter details additional useful info ```