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Flashcards in Adverse drug reactions Deck (49)
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1
Q

Define ADRs

A

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

2
Q

Define side effect

A

Unintended effect of a drug related to its pharmacological properties and can include unexpected benefits of treatment

3
Q

How common are ADRs

A

One in 20 hospital admissions (5% of all admissions)

4
Q

How common are ADRs in hospital inpatients

A

10-20%

5th most common death

5
Q

Why are ADRs so important to avoid

A
  1. Affects QOL
  2. Increase cost of patient care
  3. Loss of confidence in doctors
  4. May mimic disease
6
Q

Adverse drug reactions to Beta blockers

A
  1. Bradycardia and heart block - primary

2. Bronchospasms - secondary

7
Q

What are type A drug reactions

A

AUGMENTED PHARMACOLOGICAL - Predictable, dose dependant and common

8
Q

What are type B drug reactions

A

(BIZARRE) - not predictable or dose depentant

9
Q

What are type C drug reactions

A

CHRONIC - Osteoporosis and steoirds

10
Q

What are type D adverse drug reactions

A

DELAYED - Malignancies after immunosuppression

11
Q

What are type E adverse drug reactions

A

END OF TREATMENT - occur after abrupt drug withdrawal

12
Q

What are type F drug reactions

A

FAILURE of therapy - Failure of OCP in presence of an enzyme inducer

13
Q

What does DoTS stand for

A

Dose relatedness
Timing of delivery (fast or slow infusion etc)
Patient susceptibility

14
Q

What are patient risk factors for ADRs

A

Patient

  1. Gender
  2. Elderly
  3. Neonates
  4. Polypharmacy
  5. Genetic predisposition
  6. Hypersensitivity
  7. Hepatic
  8. Adherence problems
15
Q

What are Drug risk factors for ADRs

A

Steep dose-response curve
Low therapeutic index
Prescriber risks

16
Q

What drug causes type A adverse drug reactions in the lungs

A
  1. Propranolol
17
Q

Why does propranolol cause bronchospasm (secondary)

A

Blocks beta-2 receptors

18
Q

What are problems with Type B adverse drug reactions

A

Not readily reversed
Less common
Life-threatenening
Allergies fall under this

19
Q

What is an idiosyncrasy

A

Inherent abnormal response to a drug
Genetic abnormality
Abnormal receptor activity

20
Q

How are enzyme-associated idiosyncrasy obtained

A

Deficiency obtained from X-linked

21
Q

Examples of enzyme deficient idiosyncrasy

A

Glucose-6-phosphate dehydrogenase and primaquine

22
Q

What can G6PD and Primaquine deficiency lead to

A

Haemolysis and haemolytic anaemia

23
Q

What factor can cause receptor abnormality idiosyncrasy

A

Malignant hyperaemia caused by general anaesthetics causes sudden huge rise in calcium concentration

  • Increase in muscle contraction
  • Increase in metabolic activity
  • Rise in body temperature
24
Q

How does vaccination cause hypersensitivity

A
  1. First dose acts as antigen
  2. Antibody produced
  3. Second dose causes antibody-antigen reaction
25
Q

Four types of hypersensitivity reactions

A

Type A - Allergy and anaphylactic
Type B - AntiBody
Type C - immune Complex reaction
Type D - Delayed Hypersensitivity

26
Q

Example of Type A hypersensitivity

A

Penicillin allergy

27
Q

Example of Type B hypersensitivity

A

Haemolytic anaemia

28
Q

Example of Type C hypersensitivity

A

Rheumatoid arthritis

29
Q

Example of Type D hypersensitivity

A

Contact Dermatitis

30
Q

Examples off type D adverse drug reaction s

A

Teratogenesis from thalidomide

Carcinogenesis from cyclophosphamide causing bladder cancer

31
Q

Examples of Type E adverse reactions

A

Glucocorticoid abruptly withdrawn leads to adrenocortical insufficiency
Withdrawal seizures when anti-convulsants are stopped

32
Q

4 signs we should expect an ADR

A
  1. Symptoms soon after new drug is started
  2. Symptoms after a dosage increase
  3. Symptoms disappear when drug is stopped
  4. Symptoms reappear when drug is restarted
33
Q

Most common drug to have ADRs

A

NSAIDS

Antibiotics

34
Q

Common ADRs

A
  1. Confusino
  2. Nausea
  3. Diarrhea
  4. Constipation
  5. Hypotension
35
Q

How can ADR’s be avoided

A
  1. Prevent drug interactions
  2. Inappropriate medication
  3. Unnecessary medication
36
Q

Role of MHRA

A

Responsible for approving medicines and devices for use

Watch over medicine and take action s to protect public promptly if there is a problem

37
Q

What is the yellow card scheme

A

Introduced in 1964

  1. Collects reports on ADRs
  2. Collects suspected adverse drug reactions
38
Q

Is the yellow card scheme compulsory

A

No

39
Q

Why is the yellow card scheme important

A

Acts as an early warning system for identification for previously unrecognised reactions

Provides information about factors which predispose patients to ADRs

40
Q

Advantages of yellow card scheme

A
  1. One of the most effective method of identifying rare adverse reactions
  2. Work rapidly
  3. Applied to all drugs throughout marketing life
  4. Cheap
41
Q

Disadvantages of a yellow card

A
  1. Can’t provide evidence as true number of cases is underestimated and total number of patients exposed is unknown
  2. Relies on ADR being recognised
  3. Media interest in drugs will stimulate more ADR reports
  4. Reporting high for new drugs and falls off over time
  5. NOT ALL ADRs are reported
42
Q

Why are ADRs under-reported (10% of all cases)

A
  1. Ignorance - Not sure how to report
  2. Diffidence - May appear foolish for reporting
  3. Fear - Expose myself to legal liability
  4. Lethargy - too busy
  5. Guilt - Reluctant to admit i caused it
  6. Ambition - Rather collect cases and publish them myself
  7. Complacency - Only safe drugs are marketed
43
Q

Why do we report ADRs

A

Important for patient safety

  1. Identify ADRs not identified in clinical trials
  2. Identify new ADRs ASAP
  3. Compre drugs at same therapeutic class
  4. Identify ADRs in at risk groups
44
Q

What is reported on a yellow card

A

All suspected reactions for herbal medicines and black triangle drugs

All serious suspected reactions for established drugs, vaccines and interactions

45
Q

Define black triangle drugs

A

Medicine undergoing additional monitoring

46
Q

When is the term black triangle given

A
  1. Contains new active substance
  2. Biological medicine (vaccines)
  3. Only approved under certain circumstances
47
Q

What is a serious reactions

A
  1. Fatal
  2. Life-threatening
  3. Disabling
  4. Hospitalisation
  5. Prolongs hospitalisation
48
Q

Who can report on a yellow card

A
  1. Doctors
  2. Dentists
  3. Coroners
  4. Pharmacists
  5. Nurses
  6. Patients
49
Q

What four important pieces of information must go on a yellow card report

A
  1. Suspected drugs
  2. Suspect reactions
  3. Patient details
  4. Reporter details

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