Adverse Reactions to drugs Flashcards
There is no universally accepted taxonomy for classifying adverse drug reactions. Give some examples of how they can be classified
onset: acute, subacute, delayed
degree: mild, moderate, severe
predicability: predictable and dose related, unpredictable and not necessarily dose related e.g. anaphylaxis
most classify adverse drug reactions based on the mechanism of toxicity:
-recognition
-management
-prevention
auWhat are type A adverse drug reactions?
augmented
exaggeration of a drugs normal phamacological actions when given at a usual therapeutic dose and normally dose dependent
augmented- more than jus the target tissue/organs affected
What are type B adverse drug reactions?
bizzare
novel response not expected from known pharmacological actions of the drug
less common
idiosyncratic reactions and anaphylaxis
What are type C adverse drug reactions?
continuing reactions
persist for a very long time
e.g. osteoradionecrosis of the jaw with bisphoshonates
What are type D adverse drug reactions?
delayed
become more apparent with time after the use of a medicine
timing makes it difficult to detect
e.g. leucopenia which can occur up to 6 weels after a dose of lomustine
What are type E adverse drug reactions?
End of use reactions
associated with withdrawals of a medicine
e.g. insomnia, anxiety and perpetual disturbances following withdrawal of benzodiazepines
Q
Adverse drug reactions can be classified according to the DoTS pneumonic. What does it stand for?
dose related
time related
susceptibility factors
Type A adverse drug reactions have __________ effects. Give an example of this
extension effects
giving too much warfarin to reduce the risk of a peripheral vascular thrombosis may result in spontaneous bleeding
What the normal effect of a therapeutic dose of warfarin?
aims to increase prothrombin time so that INR is between 2-3
Frusemide is often prescribed in heart failure where oedema is a concern. Name the therapeutic effect and the toxic extension of this drug
therapeutic effect: diuresis- reduction of fluid
toxic extension- hypovolemia- reduced blood volume; hypotension, can cause the heart (in failure) to attempt to work harder; more damage to the heart
Heparin is an IM/IV anticoagulant, indicated for thromboemobolic dissolution. State the therapeutic effect and toxic extension of this drug
inhibit coagulation
spontaneous bleeding
Insulin is prescribed for some patients with diabetes mellitus. State the therapeutic effect and toxic extension of this medication
reduce blood glucose
hypoglycaemia
Vecuronium is often prescribed with GA for abdominal surgery. State the therapeutic effect and the toxic extension of this medication
skeletal muscle relaxation
prolonged respiratory paralysis
How do type A adverse drug reactions come about?
- side effects may be produced by the same drug-receptor interaction as the therapeutic effect but at a different tissue or end organ
*whether the side effect is toxic or therapeutic is dependent on the purpose of the treatment
Give an example of a type A adverse reaction that can be used therapeutically
- atropine (anticholinergic) given for GI hypermobility can cause xerostomia
- however, it can be used therapeutically in cases of hypersalivation
What oral side effect does diphenydramine (bendryl) have?
xerostomia
What oral side effect does griseofulvin have?
black hair tongue
there is an overgrowth of pigmented papillae stimulated by bacterial products
What oral side effect does phenytoin have?
gingival hyperplasia
What oral side effect does tetracycline (doxycycline) have?
pigmentation and hyperplasia of teeth
What side effect does amoxycillin have?
dermatitis
persistent scratching, localised reaction
(allergy)
What side effect does cyclophosphamide have?
used for autoimmune control- used to treat many cancers
alopecia
this chemotherapeutic agent causes alopecia
What is the side effect of methandrostenolone?
acne
What is the side effect of minoxidil?
hypertrichosis
excessive hair growth anywhere on the body- men or women
What is the side effect of ciprofloxacin?
arthralagia
What is the side effect of hydralazine?
arthralagia
What is the side effect of phenobarbitol?
osteomalacia
softened and weakened bone
What is the side effect of prednisolone?
osteoporosis
prevents the maturation of collagen
remember steroids prevent bone growth
What is the side effect of baclofen?
Baclofen is an antispasmodic drug, used to treat facial pain
blurred vision
What is the side effect of digoxin?
anti-arrhytmic drug
yellow vision
What is the side effect of gentamicin?
antibiotic
ototoxicity
hearing and balance problems
this is a very well known side effect
What is the side effect of thioridizine?
pigmentary retinopathy
What is the side effect of cytosine arabinoside?
pancytopenia
deficiency in all cellular blood components (RBC, WBC, platelets)
What is the side effect of prilocaine?
amide local anaesthetic
methaemoglobinaemia
methaemoglobin has a preference for CO2
What is the side effect of sodium valproate?
thrombocytopenia
deficiency of platelets
What is the side effect of zidovudine?
antiviral drug
granulocytopenia
(particularly of neutrophils)
eosinophils, basophils
What are the metabolic side effects of aspirin?
metabolic acidosis
What is the metabolic side effect of frusemide?
used in heart failure
hyperglycaemia
What is the metabolic side effect of Nadolol?
hypoglycaemia
What is the metabolic side effect of rifampicin?
anti-tuberculosis drug
jaundice
What are the side effects of atorvastatin?
myalgia (muscle pain)
burning mouth
What is the side effect of chlorpromazine on the NM system?
neuromuscular system
tardive dyskinesia
parkinsonism
parkinsonism- no deficiency in the substantia nigra