Chapter 2 Qs Flashcards
Q2.1 Give an example of 2 drugs that should be stopped in a pt with haemoptysis
Antiplatelets: Aspirin
Anticoagulants: LMWH
Q2.1 Give an example of 2 pescriptions that should be stopped in a hyperkalaemic patient
ACEi (ramipril)
IV fluid with added potassium
Q2.2 What is the mechanism of action of the following antiemetics:
- Metoclopramide:
- Domperidone:
- Cyclizine:
- Metoclopramide: dopamine antagonist, crosses BBB, exacerbated parkinsonian symproms
- Domperidone: dopamine antagonist Doesn’t cross BBB, safe in PD
- Cyclizine: antihistamine anti-emetic
Q2.3 How do ACE-i cause dry cough?
ACE-I cause dry cough through accumulation of bradykinin via reduced degradation by ACE.
Q2.3 How do ACE-i’s cause hyperkalaemia?
ACE-i cause hyperkalaemia via reduced aldosterone production, and reduced K+ excretion in kidneys (aldosterone antagonists do this too).
Q2.4. How do the following two drugs cause ‘stomach upset’:
- Ibuprofen
- Prednisolone
- Ibuprofen, NSAID, inhibits prostaglandin synthesis needed for gastric mucosal protection.
- Prednisolone, Oral steroids inhibit gastric epithelial renewal.
Both → indigestion/dyspepsia.
Q2.4. How do the following two drugs cause renal falure:
- Ibuprofen
- Ramipril
- Ibuprofen, NSAID inhibits prostaglandin synthesis → reduced renal artery diameter → reduced kidney perfusion + function.
- Ramipril, ACEi, reduces angiotensin II production req for preserving glomerular filtration when blood flow is reduced
Q2.6 Common PMHx contra-indication for Ibuprofen
Asthma: NSAIDs (e.g. ibuprofen) cause bronchoconstriction, so avoid unless strictly necessary + under supervision (not at home).
Q2.6 Important to remember regarding PRN medications
For prescription to be valid, must write maximum PRN frequency – can’t just write “as required” on its own.
Q2.6 CI for trimethoprim in a pt with RA?
Trimethoprim = folate antagonist, so CI with methotrexate (also folate antagonist) as risk of BM toxicity → pancytopenia + neutropenic sepsis.
Q2.6 Important to remember in a septic pt on methotrexate
If on methotrexate + septic, must stop it pending exclusion of neutropenic sepsis.
Q2.7 Important side effect on CCB
CCBs (e.g. amlodipine) cause ankle swelling. Do not use in HF.
Q2.7 How long after an ischaemic stroke should we wait to start LMWH?
Stop LMWH (e.g.enoxaparin) for 2 months (duration varies throughout UK) following an ischaemic stroke
Q.2.8 How to check how to manage warfarin and INR on the BNF
Check BNF for this by typing in “warfarin INR”/Oral anticoagulants in search bar.
If patient has high warfarin (INR 5-8), withhold a few doses.
If patient on warfarin with INR >2 (i.e. therapeutic), then do not give prophylactic heparin as increases risk of bleeding unnecessarily.
Q2.9 Important trivia re asthma
- Beta Blockers
- NSAIDS
- Apsirin (NSAID)
- Beta-blockers; strictly CI (can precipitate bronchospasm)
- NSAIDs; use with caution (can precipitate bronchospasm)
- If asthmatic already on NSAID without problem, may continue.
- Aspirin, although an NSAID, very rarely worsens asthma – so commonly (but cautiously) used.