14. Ethical and Legal Aspects of Prescribing + Adverse Drug Reactions Flashcards
What is the biggest killer in the world? And in the UK (male/female)?
What is off-label medication?
What do the following NICE classifications of medicinal products stand for?
GSL
P
POM
CD
World: IHD (12.6%). UK: male = IHD (14.8%), female = dementia (13.3%)
Use/route outside the liscensed indication of the product e.g. amitriptyline licensed for depression but not neuropathic pain.
General sale list
Pharmacy only medicines
Prescription only medicines
Controlled drugs
What do the following prescription abbreviations mean?
- od
- bd
- tds
- qds
- om:on
- prn
- sos
- stat
- once a day
- twice a day
- three times a day
- four times a day
- in the morning:at night
- when required
- if necessary
- immediately
What do the following route abbreviations mean?
- IM
- IV
- O
- PR
- PV
6: SC - TOP
- INH
- NEB
- IT
- intramuscular
- intravenous
- oral
- per rectum
- per vagina
- subcutaneous
- topically
- inhaled via inhaler
- inhaled via nebuliser
- intrathecal
Which of these statements are true?
a) Most adverse drug reactions are dose dependent
b) Most adverse drug reactions are irreversible
c) It is not safe to stop most drugs immediately
d) Information about ADRs comes exclusively from pharma companies
e) Phase III pivotal clinical trials evaluate all likely adverse effects
What is an ADR?
- *a) TRUE** - most are Type A (augmented)
b) FALSE - most are type A so once got rid of all drugs = reversible
c) FALSE - it is
d) FALSE - comes from spontaneous reporting systems e.g. Yellow Card
e) FALSE - they never can b/c of the natural size of them
Any undesirable effect of a drug beyond its anticipated therapeutic effects occuring during clinical use
How might ADRs in children be different to adults?
What is the A-E classification of ADRs?
Altered frequency (e.g. increased frequency of hepatotoxicity to valporate), severity (e.g reduced susceptibility to hepatotoxicity from paracetamol in infants), or unique to childhood population (e.g. growth supression from corticosteroids). Kids don’t metabolise drugs as well.
Type A = augmented
Type B = bizarre
Type C = continuing
Type D = delayed
Type E = end-of-use
A and B most common in 90% of hospital ADRs
What is a Type A (augmented) ADR?
What can they be divided in to?
Define pharmacokinetic, pharmacogenomic and pharmacodynamic.
Exaggeration of a drug’s normal pharmacological actions when given at usual therapeutic doses, normally dose-dependent, usually identified in clinical trials. Most common: antiplatelets, diuretics, NSAIDs, anticoagulants.
Primary pharmacology: e.g. Aspirin - bleeding
Secondary pharmacology: e.g. Aspirin - gastric irritation
Pharmacokinetic: what your body does to drug
Pharmacogenomic: how you genes interact with drug
Pharmacodynamic: how drug works in you
Type A example 1
64 year old man, PC: increased DIB over 1w with ankle swelling, PMH: stable CAD (coronary artery disease), CKD (chronic kidney disease) stage III and T2DM. DH: furosemide 20mg, bisoprolol 10mg, ramipril 5mg, simvastatin 20mg, clopidogrel 75mg. Recently started new medication for back pain.
Which of the following medications is the likely cause:
paracetamol, tramadol, codeine, diclofenac or fentanyl?
Got fluid overload most likelt related to kidney or heart failure. Diclofenac b/c it’s an NSAID - adverse cardiovascular effects and kidney function effects.
NB: NSAIDs block COX so decreases prostaglandin formation. Can affect platelets and kidney via increases in circulating volume -> heart failure risk.
Type A example 2
78 year old woman with TDS care package, PC: increased confusion over past 4w following a fall, PMH: AF, controlled hypertension, DH: Lisinopril 10mg, indapamide 1.5mg, warfarin, simvastin 20mg, bisoprolol 5mg.
Which of the prescribed medications is the likely cause of the confusion?
Warfarin -> subdural haematoma (she fell and hit her head -> bleeding in skull).
Type A example 3
33 year old woman, PC: life threatening GI bleed, PMH: APS, multiple PE/DVTs, DH: Prednisolone 5mg, warfarin. Started antimicrobial for cutaneous infection.
Which of the following medications has precipitated the bleed?
Amoxicillin, cefuroxime, flucloxcillin, co-amoxiclav, fluconazole
Fluconazole -> reduced metabolism of wafarin
NB: warfarin inhibits hepatic production of vitamin K dependent coagulation factors and cofactors, by inhibiting vitamin K expoxide reductase.
Type A example 4
31 year old man with CAP (community acquired pneumonia), PC: unwell during 2nd dose of antibiotic (part given), PMH: none, DH: IV co-amoxiclav 1.2g
Which of the following is the most appropriate immediate action?
- IM adrenaline
- IV hydrocortisone
- nebulised salbutamol
- IV fluids
- aspirate cannula
Adrenaline is treatment of choice for anaphylaxis
What is a Type B (bizarre) ADR? Give an example.
What is a Type C (continuing) ADR? Give an example.
Novel responses that are unexpected from known pharmacological response. Difficult to predict, often immune-mediated. E.g. anaphylaxis
Reactions persist for a relatively long time after discontinuation of the medication. Dose and time-dependent, reaction independent of medication T1/2. E.g. bisphosphonates -> jaw osteonerosis, corticosteroids -> osteoporosis
What is a Type D (delayed) ADR? Give an example.
What is a Type E (end-of-use) ADR? Give an example.
Reactions that become apparent some time after use of a medication. E.g. chemotherapy -> infertility, carbimazole -> agranulocytosis (leukopenia), typical antipsychotics -> tardive dyskinesia (involuntary movements), many drugs -> teratogenicity (disturb foetal development), thalidomide, stilbestrol.
Reactions associated with withdrawal of medications. E.g. benzodiazepines -> agitation/insomnia, corticosteroids (if on long term for e.g. IBD)-> adrenal insufficiency, opiates -> flu-like withdrawal
What is the rule of 3 for phase III trials?
If an adverse effect in a clinical trial is not seen in n subjects then you can be 95% confident it will occur in <1(n/3)
