W25 Yellow Card Scheme Flashcards
What is an Adverse Drug Reaction?
An ADR is a response to a medicinal product
which is noxious and unintended.
ADRs may arise from the use of a product
within or outside the terms of the marketing
authorisation, e.g. from off-label use,
medication errors, overdose, misuse, or abuse.
Adverse Drug Reactions vs. Side
Effects?
ADR – unpleasant or unwanted
Side effects – may be beneficial as well as harmful
- First generation antihistamines e.g.
- promethazine in Night Nurse
- diphenhydramine in Nytol
- Sildenafil (Viagra) – initial development for hypertension but licensed for erectile dysfunction
Why are ADRs important?
- Financial burden on NHS £466m
- ADRs are 4th leading cause of death in the USA
- Major clinical problem – increase morbidity and mortality
Classification of ADRs:
Common ADRs – Approx. 80% of
ADRs
What are Type A (‘Augmented’) ADRs?
Predictable, dose related
Bradycardia with beta blockers
Constipation with opioids
Usually not severe
* Gastritis from NSAIDs
Uncommon but often well recognised
ADRs
What are Type B (‘Bizarre’) ADRs?
Unpredictable, not dose related
May be very severe / fatal
* Achilles tendonitis caused by quinolone antibiotics
* Stevens-Johnson syndrome following ibuprofen therapy
With new drugs ADRs not well recognised
The Black Triangle is found on marketing information that represents what?
What MUST appear on a yellow card?
New medicines
The suspect drug name
Report all suspected ADRs for new drugs
(marked ▼) – even if not serious
The black triangle▼ indicates a medicine is
being intensively monitored.
It is assigned to:
New drugs
New combinations of drugs
Novel routes or delivery systems for drugs
Significant new indications for drugs
Other Classification of ADRs
Type C (Chronic treatment effects)
* Osteoporosis with steroids
Type D (Delayed effects)
* Drug induced cancers
Type E (End of treatment effects)
* Withdrawal syndromes with opiates
Type F (Failure of therapy)
* Unexpected failure of therapy due to drug interaction
* e.g. Combined Oral Contraceptive and rifampicin
Type G (Genetic or Genomic)
* Irreversible genetic damage (carcinogens, teratogens)
Important factors in ADRs:
What does D in DoTS stand for?
DOSE at which the ADR can occur
* At doses below therapeutic doses
* Anaphylaxis with penicillin
* In the therapeutic dose range
* Nausea with morphine
* At high doses
* Liver failure with paracetamol
What does DoTS stand for?
Dose, Time, Susceptibility
What does T in DoTS stand for?
-Time
Time of onset can be characteristic
* With the first or second dose
* Anaphylaxis with penicillin
* Early, or after a time, or with long-term treatment
* First few days: nitrate induced headache
* 10 days – 10 weeks: peptic ulcer with NSAIDs
* Several weeks: drug-induced Cushing’s syndrome
* On stopping treatment (withdrawal)
* Opiate withdrawal syndrome
* Delayed
* Drug induced cancer
What does S in DoTS stand for?
Susceptibility of patients can be defined
* Genetics – Greek and African origin are more likely
to experience breathing problems with codeine
* Age – parkinsonism with metoclopramide in
adolescents
* Sex – ACE-inhibitor induced cough more likely in
women
* Physiological state – phenytoin in pregnancy
* Exogenous drugs or foods – warfarin, cranberry
juice, and increased INR
* Disease – gentamicin & deafness in renal failure
High Risk Populations of ADRs?
Younger Children
* Dose needs tailoring to age/weight
* Not able to identify potential error
Older adults
* Co-morbidities
* Polypharmacy
* Diminished reserves
* Reduced renal or hepatic function
What are the Top 10 drugs/drug groups associated with ADRs?
NSAIDs
Antidepressants
Diuretics
Opioids
Digoxin
Prednisolone
Beta-blockers
Warfarin
ACE inhibitors
Clopidogrel
What else may indicate an ADR?
- Abnormal clinical measurements while on drug therapy e.g. B.P, temp, pulse, blood glucose and weight
- Abnormal laboratory results while on drug therapy
- biochemical or haematological
- New therapy started which could be used to treat ADR
- Reducing the dose or stopping the suspected drug alleviates the symptoms
- If drug reintroduced and symptoms recur, the drug is probably responsible
- Listen to patients own concerns
Are ADRs avoidable?
70% of ADRs are potentially avoidable
* Avoid unnecessary drug use
* Avoid/reduce drug interactions
-check the patient’s drug history before prescribing
* Consider risk factors for ADRs e.g. age extremes, reduced
hepatic and renal function
* Avoid new (black triangle) drugs
* Patient counselling
* Monitor treatment & optimise dose
* Consider prophylactic therapy where appropriate
