Section 2: Prescription review Flashcards
When do you stop COCP pre-operatively?
4 weeks before surgery
When do you stop lithium pre-operatively?
24h before major surgery, but dose may be continued for minor surgery with careful monitoring of fluids and electrolytes.
When do you stop spironolactone pre-operatively?
K+ sparing diuretics are withheld on the morning/ day of surgery because of the risk of hyperkalemia. This also applies to ACE-i and ARB. which are a/w severe hypoTN after anaesthesia. The BNF treatment summary is entitled ‘Surgery and long-term medication’.
When do you stop ramipril pre-operatively?
24h before surgery, due to risk of severe hypotension under general anaesthetic.
Dose and frequency of methotrexate?
Once weekly. Usually a loading dose dependent on condition being treated, with stepwise 2.5mg increase weekly.
If patient is nauseous and vomiting, what antiemetic would you prescribe?
Cyclizine 5mg TDS, metoclopramide 10mg TDS given by IV/ IM/ SC i.e. non-oral routes
When do you stop aspirin before surgery?
1 week
Do you stop metformin before surgery?
Yes, due to risk of lactic acidosis when patients are NBM i.e. prolonged pre-operative fasting. Stop it 48h before and sometimes 48h after surgery.
Which diuretics cause hypo and hyperkalemia?
Hypo - loop and thiazide
Hyper - K+ sparing i.e. aldosterone antagonists ~ also ACE-i
What anti-folates do you need to avoid prescribing together?
Methotrexate, trimethoprim, proguanil (anti-malarial), pyrimethamine
Following an acute stroke, when do you start heparin thromboprophylaxis?
Around 2 months following the stroke due to risk of bleed (although this varies throughout the UK) - consider mechanical compression
If a patient is taking warfarin with a therapeutic INR, do they still require prophylactic heparin in hospital?
No. This increases risk of bleeding unnecessarily.
Why should verapamil not be used with beta blockers?
Verapamil is a cardio selective CCB and when used with beta blockers may cause profound bradycardia (even asystole) and hypotension.
What drugs to stop in asthma exacerbation?
Ibuprofen and beta blockers - these cause bronchospasms
Aspirin is usually fine in asthmatics but usual at dose of 75mg for cardioprotection (and max 300mg for stroke)
What routes are insulin given by?
Always S/C except for sliding scales using short-acting insuln, which is given IV e.g. Actrapid or NovoRapid
What antibiotic to treat UTI in pregnancy?
In 1st trimester, avoid trimethoprim (folate antagonist, NTDs)
In 3rd trimester, avoid nitrofurantoin.
Co-amoxiclav 625mg 8 hourly for 3 days if not penicillin allergic.
Give folic acid anywayn
What are the sick day rules for patients with Addison’s?
Increase intake of steroids to provide adequate cortisol for stress response.
Patient with acute asthma is on ibuprofen and bisoprolol and reg salbutamol inhaler. When treated with salbutamol nebs, what should be withheld?
Stop ibuprofen, bisoprolol, salbutamol inhaler
Patient has fast AF and peripheral oedema but with no adverse features. What is appropriate management?
Rate control, which has a mortality benefit in heart failure beta blockers (avoid in asthmatics), diltiazem (avoid in fluid retention) or digoxin.
Consider pharmacological cardioversion.
What drug is contraindicated in peripheral vascular disease?
Beta blockers e.g. atenolol, which can cause peripheral vasoconstriction and worsen ischaemia.
If patient has signs of critical ischaemia, also avoid ACE inhibitors.
What drugs exacerbate heart failure?
Calcium channel blockers e.g. diltiazem, amlodipine, verapamil
Corticosteroids
Piogitazone
Why is it dangerous to withhold steroids for patient on long term Tx?
Long term steroid use may result in chronic adrenal suppression. Abrupt stoppage of steroid may lead to an Addisonian type crisis (hypoglycaemia, hypotension, hyperkalemia)
What are the starting and max dosages of citalopram in adults and elderly?
Adult - 20mg OD up to 40mg OD
Elderly - 10mg OD up to 20mg OD
What drugs can cause iron deficiency anaemia?
NSAIDs e.g. aspirin or ibuprofen - due to reduced gastroprotection.
What drugs can cause hypoglycaemia?
Sulfonylureas e.g. gliclazide
SGLT2 inhibitors e.g. sitagliptin, dapagliflozin
Thiazolidinediones e.g. pioglitazone
Insulin
What drugs cause urinary retention?
Morphine and other opioids. Also anticholinergics (antipsychotics, antidepressants, detrusor relaxants), general anaesthetic, alpha agonists (e.g. clonidine, methyldopa), benzodiazepines, NSAIDs, CCBs, antihistamines, alcohol.
What drugs may cause confusion?
Centrally acting drugs such as morphine, anticholinergics, antipsychotics, antidepressants, metoclopramide, anticonvulsants, anti-histamines, corticosteroids, etc.
What drugs are eliminated by the kidneys? (adjust dose in renal impairment!)
CVS: atenolol, digoxin Neuro: opioids, gabapentin, pregablin, lithium Micro: aminoglycosides, penicillins Haem: LMWH Endo: metformin
Which drugs should be withheld if patient is dehydrated?
ACE inhibitors/ ARBs, diuretics, NSAIDs, metformin (generally due to risk of AKI and for the latter, lactic acidosis)
What drugs lower seizure threshhold?
Opioids, isoniazid, metronidazole, beta-lactams (in toxic dose), buprorpion, TCAs, antipsychotics
Should metformin and insulin be continued pre-operatively?
Metformin should be stopped the day before surgery, alongside any insulin. These should be converted to sliding scale insulin/ VRII.
What drugs should be stopped pre-operatively?
- ACE inhibitors
- Angiotensin 2 antagonists
- Consider diuretics
- Diabetic Tx
- Aspirin, clopidogrel, dipyridamole, warfarin (unless coronary stent)
- Lithium
- NSAIDs
