Yellow card ADRs Flashcards
What does ADR stand for ?
Adverse drug reaction
What is the definition of an ADR?
Response to a drug which is noxious (harmful) and unintended
- within or outside the terms of the marketing authorisation
- or from occupational exposure (e.g. overdose)
Toxicity definition?
Exaggeration of desired therapeutic effect
Side effect definition?
Any unintended pharmacological effect of medication
When might ADRs occur?
Adverse reactions may arise from use of the product. Conditions of use outside the marketing authorisation include off-label use, overdose, misuse, abuse and medication errors.
The reaction may be a known side effect of the drug or it may be new and previously unrecognised.
What is an adverse drug event?
NOT the same as an ADR
- Any undesirable event whilst taking a medication e.g. hit by a car whilst on a specific medication
What 4 drug groups account for 50% of ADR admissions in the UK?
- Antiplatelets (including Aspiri)
- Diuretics
- NSAID’s
- Anticoagulants
Example of an ADR mimicking disease state?
Patient is prescribed Fentanyl patch 12mcg/hour every 72 hours
BNF (palliative care section) : Fentanyl patch 12mcg = 30mg oral morphine daily
Using increasing oramorph as breakthrough (10mg /day)
>50% increase in dose
Patient becomes drowsy, hallucinations, falls
?opioid overdose or cerebral metatasis
What is a type A ADR reaction?
- AUGMENTED reaction
- usually dose related
- Exaggeration of drug’s normal pharmacological action
- low mortality
- high morbidity
- Greater susceptibility in renal or hepatic disease, young and old
- 80% of all ADR’s
Examples of type A reactions?
- Beta blocker causing bradycardia and hypotension
- respiratory depression with opioids
- bleeding with warfarin
- also include those that are not directly related to the desired pharmacological action of the drug (e.g. dry mouth that is associated with tricyclic antidepressants).
What is a type B reaction?
- BIZARRE
- unpredictable response
- not dose related
- low morbidity
- high mortality
- lower incidence
Example of a type B reaction?
- Allergic reactions
- Anaphylaxis with penicillin
- Skin rashes with antibiotics - Idiosyncratic reactions
- Genetically determined effects
- G6PD deficiency
What drugs have definite risk of haemolysis in most GP6D-deficient individuals?
Dapsone, Nitrofurantoin, Primaquine, quinalones, co-trimoxazole
What is anaphylaxis?
Anaphylaxis is a severe, life-threatening, generalised or systemic hypersensitivity reaction. It is characterised by rapidly developing, life-threatening problems involving: the airway (pharyngeal or laryngeal oedema) and/or breathing (bronchospasm with tachypnoea) and/or circulation (hypotension and/or tachycardia). In most cases, there are associated skin and mucosal changes
What is Stevens Johnson Syndrome?
Stevens-Johnson syndrome is a rare condition arising from ‘over-reaction’ of the immune system to a trigger such as a mild infection or a medicine, leading to blistering and peeling of the skin and surfaces of the eyes, mouth and throat
What drugs cause Stevens Johnson Syndrome?
- antibacterial sulfa drugs (sulfadiazine, sulfamethoxazole/trimethoprim)
- anti-epileptic drugs (phenytoin, carbamazepine, lamotrigine, phenobarbital)
- allopurinol
- NSAIDs
- antibiotics (penicillins)
What is toxic epidermal necrosis (TEN)?
Another form of severe rash from drug reaction
- Presents in variety of patterns
- Typically: fever, flu like symptom before skin eruption
- Crops on hands and feet more often than trunk.
- May be blisters, papular or erythmatous
What is a type C ADR?
- Chronic
- Long term effects eg. Osteoporosis with steroids, analgesic nephropathy
What is a type D ADR?
- delayed
- teratogenesis/carcinogenesis
What is an example of a type D reaction?
leucopoenia, which can occur up to six weeks after a dose of lomustine
What is a type E ADR?
- End of dose
- Withdrawal effects after long-term treatment
Example of type E ADR?
- SSRI withdrawal
- insomnia, anxiety and perceptual disturbances following the withdrawal of benzodiazepines
What is a type F ADR?
- failure
- e.g. oral contraceptive pill and rifampicin interaction
What does the yellow card collect information on?
ADRs to all medicines including:
- Vaccines
- Blood factors and immunoglogulins
- Herbal medicines
- Homeopathic remedies
- Contrast media
- Prescriptions and OTC
- Unlicensed medications
- Medical devices adverse incidents
- Defective medicines (unacceptable quality)
- Counterfeit medicines and devices
