Adverse drug reactions Flashcards
What condition does thalidamide cause
phocomelia - shortened underdeveloped limbs etc
What is an adverse drug reaction
noxious, unintended reaction after normal dose OR abuse, medication error, overdose
Most common drug and ADRs causing hospital admission
NSAIDs
Diuretics
Warfarin
ACE/AII inhibitors
Beta blockers
Opiates
Digoxin
Prednisolone
Clopidogrel
Common adverse reactions of NSAIDs
Gi complications
Cerebral haemorrhage
Renal impairment
alletgic type - Wheezing, Rash
Diuretics adverse reactions common
Renal impairment
Hypotension
Electrolyte disturbance
Gout (uric acid accumulate)
Warfarin and clopidogrel adverse reactions
warfarin - bleeding
Clopidogrel - GI bleeding
beta blockers adverse reactions
Bradycardia
Heart block
HYpotnesion
Wheezing
Opiates common adverse reactions
Constipation
Vommitting
Confusion
Urinary retnetion
Digoxin adverse effect
Toxicity esp in renal impairment
Prednisolone adverse effects
GI complications, hyperglycaemia. osteoporotic fracture, worsening diabtees, skin bruising
ACE inhibitors/AII inhibitrs common adverse effects
renal impairment, hypotnesion, electrolyte disturbances
A-E of adverse drug reactions
Augmented
Bizarre
Chronic
Delayed effects
End of treatment
What is an augmented drug reaction
dose related and predictable
avoidable
examples of augmented drug reactions
insulin causing hypoglycaemia
Warfarin causing bleeding
Nitrates causing headaches (increased blood flow to cerebral vessels)
What are bizarre drug reactions
Not dose related, unpredicatable
What does digoxin toxicity cause
leading to N+V and arrhythmias
Examples of bizarre drug reactions
Penicllin anyphylaxis
Halothane -> hepattis
Chloramphenicol - agranulocytosis
Chronic adverse drug effects
Variable - only with prolonged use
Steroid ADRs from chronic use
Steroids -> osteoporosis, steroid cushings syndrome, metabolic syndromes
What drug used chronically can cause tardive dyskinesia
Phenothiazine
What drug used chronically can cause pulmonary hypertension
Fenfluramine
What are delayed ADRs
Effects that occur some time after drug discontinuation eg drug induced foetal abnormalities, durg induced cancers recipients or offspringeg immunosupressed, renal transplants sqamous cell carcinomas, dihydroestriol in pregnanc - female children -> vaginal cancer
What are end of treatment ADRs
Effects occur on withdrawal of drug
Examples of end of treatment ADRs
Adrenocortical insufficiency after steroid treatment
Drug withdrawal seizures
Withdrawal reactions following paroxetine
Drugs causing gynaecomastia
Spirinolactone
Oestrogens
Methyldopa
Digoxin
Drugs causing galactorrhea
Antipsychotics
Tricyclics
Metoclopramide
Oestrogens
Methyldopa
What condition is morbidiform skin rash seen in when cillin antibiotics are used
Glandular fever
Severe skin reactions to drugs increasing in severity
Eytherma multiforme
Steven johnsons syndrome
Toxic epidermal necrolysis
When does stevens johnson syndrome become toxic epidermal necrolysis
> 30% of skin surface involved and extensive mucous membrane damage
What is steven johnsons syndrome
Flu like symptoms -> rash -> blisters -> top layer of skin sheds
hospitalisation for recovery
What can corticosteroid use in childhood cause
Short statue - premature fusing of epiphyses
What can tricycline antibiotics acuse in childhood
Yellow staining of enamel teeth
What cancer is caused by long erm immunosupressant use after renal trnsplant
Squamous cell carcinoma
What type of drug reaction is sus if improvement of condition after drug discontinued or dose reduced
Type A dose related ADR
What is a rechallenge of a drug in ADR
Reinteoduce drug that suspect caused reaction to see if happens again
What test result supports an ADR type A
High plasma drug concentrations (easy to measure in digoxin, theophylline)
Criteria for ADR suspicion
Timing of symptoms with drug treatment
Improvement after discontinued or dose redued
Worsening after rechallenge
Ass w high plasma drug concentrations
Reaction prev recognised as side effect of drug patient on
Illness commonly result of ADR eg postural hypotension, confusion
Exclusion of other causes
How to avoid anaphylaxis from drugs - notes, administering, what patient group
Careful drug history
PUT IN NOTES - record on drug charts and hospital and GP notes
Doubel check before administering drugs
Inject first dose slowly
Particular care in atopic patients
Methods for avoiding ADRs
Only prescribe when clear indication
Use drug with most favourable risk-benefit
Check for prev ADRs/allergu
Careful paitent educations
Monitor therapy
Particular care in susceptibel patients eg elderly, prev ADR
What patient education need ot give around drugs prescribed
Appropriate use of drug
Common an/or important adverse effects - BNF/SPC
What skin reaction can anticonculsants cause
Steven johnsons syndrome/toxic epidermal necrolysis
What % of hospital admissions are caused by ADRs?
5-7%
Annual cost of ADR to NHS
250M
Most common drugs causes of ADRs
NSAIDs : GI complications, cerebral haemorrhage, renal impairment, wheezing, rash
Diuretics: renal impairment, hypotension, electrolyte disturbances, gout
Warfarin: bleeding
ACE inhibitors /Angiotensin II receptor antagonists: renal impairment, hypotension, electrolyte disturbances
Beta blockers: Bradycardia, heart block, hypotension, wheezing
Opiates: Constipation, vomiting, confusion, urinary retention
Digoxin: Nausea, vomiting, confusion, bradycardia
Prednisolone: GI complications, hyperglycaemia, osteoporotic fracture
Clopidogrel: GI bleeding
How to treat gynaecomastia if causing psychological distress
Surgery
Common side effect of nicorandil
Anal ulceration and anal fissures
What is foetal valproate syndrome
Delayed reaction following valproate exposure in utero -> broad forehead, thin arched eyebrows, flat nsala bridge, low set ears, short nose, thin upper lips.
more likely to develop autism and ADHD
When can valproate be prescribed to women
When they are not of child bearing age or on the pregnancy prevention programme - annual check ups, highly effective contraception
What anticonvulsants are less teratogenic than phenytoin, carbamazepine and valproate
Lamotrigine, levetiracetam
Exapmples of teratogenic drugs
warfarin, lithium , valproate, thalidomide, phenytoin, isotretinoin
What gene is Stevens Johnsons syndrome more likely with
HLA-B1502 allele - thai or han chinese ethnic origin - esp carbamazepine or phenytoin
What idiosyncratic reaction can abacavir cause
Serious hypersenstivity
What idiosyncratic reaction can flucloxacillin cause
hepatits
What idiosyncratic reaction can chloramphenicol cause
aplastic anaemia
what idiosyncratic reaction can simvastatin cause
Rhabdomyolysis - SCLO1B1
Rare ADRs picked up by yellow card scheme
1 in 6,000 - Chloramphenicol-induced aplastic anaemia
1 in 10,000 - Halothane-induced jaundice
1 in 10,000 - DVT with oral contraceptives
1 in 10,000 - MI with oral contraceptives
1 in 20,000 - VT with terodiline
1 in 50,000 - VT with terfenadine
Common drugs with narrow therapeutic index
Carbamazepine
Cyclosporine
Digoxin
Levothyroxine
Lithium carbonate
Phenytoin
Tacrolimus
Theophylline
Warfarin
What neuro features may a patinet get when chronically taking metaclopramide for gastroparesis
Parkinsonian features
What drugs delay gastric emptying
Tricyclic antidepressants, opiates and anti-muscarinic drugs
Why does metaclopramide increase rate of absorpiton of other drugs
Increase gastric emptying
What antibiotics are made less orally available when taken with antacids
Tetracyclines, quinolones
Form complex w antacids
What drugs worry about with lithium -> poisonning
Any drugs causing sodium loss eg diuretics - proximal tubules donet differentiate between sodiuma nd lithium
Why can ACEis cause angio-oedema
Accumulation of bradykinin
What drug should be administerd in an iron overdose
Deserrioxamine - chelates iron
When should paracetemol levels be measured after an overdose/
If overdose >75mg/kg
Determine if need acetylcysteine
If present after 8 hrs acetylcysteine started before results received
What test is best indicator of prognosis in paracetamol overdose
INR
Antichoinergic vs stimulant overdose
Same - low BP, tachycardia, dilated pupils
Anticholinergic - dry skin, absent bowel sounds
Stimulant - sweating, increased bowel sounds
