Section 2: Prescription review

Question 1

When do you stop COCP pre-operatively?

Answer 1

4 weeks before surgery

Question 2

When do you stop lithium pre-operatively?

Answer 2

24h before major surgery, but dose may be continued for minor surgery with careful monitoring of fluids and electrolytes.

Question 3

When do you stop spironolactone pre-operatively?

Answer 3

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’.

Question 4

When do you stop ramipril pre-operatively?

Answer 4

24h before surgery, due to risk of severe hypotension under general anaesthetic.

Question 5

Dose and frequency of methotrexate?

Answer 5

Once weekly. Usually a loading dose dependent on condition being treated, with stepwise 2.5mg increase weekly.

Question 6

If patient is nauseous and vomiting, what antiemetic would you prescribe?

Answer 6

Cyclizine 5mg TDS, metoclopramide 10mg TDS given by IV/ IM/ SC i.e. non-oral routes

Question 7

When do you stop aspirin before surgery?

Answer 7

1 week

Question 8

Do you stop metformin before surgery?

Answer 8

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.

Question 9

Which diuretics cause hypo and hyperkalemia?

Answer 9

Hypo - loop and thiazide

Hyper - K+ sparing i.e. aldosterone antagonists ~ also ACE-i

Question 10

What anti-folates do you need to avoid prescribing together?

Answer 10

Methotrexate, trimethoprim, proguanil (anti-malarial), pyrimethamine

Question 11

Following an acute stroke, when do you start heparin thromboprophylaxis?

Answer 11

Around 2 months following the stroke due to risk of bleed (although this varies throughout the UK) - consider mechanical compression

Question 12

If a patient is taking warfarin with a therapeutic INR, do they still require prophylactic heparin in hospital?

Answer 12

No. This increases risk of bleeding unnecessarily.

Question 13

Why should verapamil not be used with beta blockers?

Answer 13

Verapamil is a cardio selective CCB and when used with beta blockers may cause profound bradycardia (even asystole) and hypotension.

Question 14

What drugs to stop in asthma exacerbation?

Answer 14

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)

Question 15

What routes are insulin given by?

Answer 15

Always S/C except for sliding scales using short-acting insuln, which is given IV e.g. Actrapid or NovoRapid

Question 16

What antibiotic to treat UTI in pregnancy?

Answer 16

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

Question 17

What are the sick day rules for patients with Addison’s?

Answer 17

Increase intake of steroids to provide adequate cortisol for stress response.

Question 18

Patient with acute asthma is on ibuprofen and bisoprolol and reg salbutamol inhaler. When treated with salbutamol nebs, what should be withheld?

Answer 18

Stop ibuprofen, bisoprolol, salbutamol inhaler

Question 19

Patient has fast AF and peripheral oedema but with no adverse features. What is appropriate management?

Answer 19

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.

Question 20

What drug is contraindicated in peripheral vascular disease?

Answer 20

Beta blockers e.g. atenolol, which can cause peripheral vasoconstriction and worsen ischaemia.

If patient has signs of critical ischaemia, also avoid ACE inhibitors.

Question 21

What drugs exacerbate heart failure?

Answer 21

Calcium channel blockers e.g. diltiazem, amlodipine, verapamil
Corticosteroids
Piogitazone

Question 22

Why is it dangerous to withhold steroids for patient on long term Tx?

Answer 22

Long term steroid use may result in chronic adrenal suppression. Abrupt stoppage of steroid may lead to an Addisonian type crisis (hypoglycaemia, hypotension, hyperkalemia)

Question 23

What are the starting and max dosages of citalopram in adults and elderly?

Answer 23

Adult - 20mg OD up to 40mg OD

Elderly - 10mg OD up to 20mg OD

Question 24

What drugs can cause iron deficiency anaemia?

Answer 24

NSAIDs e.g. aspirin or ibuprofen - due to reduced gastroprotection.

Question 25

What drugs can cause hypoglycaemia?

Answer 25

Sulfonylureas e.g. gliclazide SGLT2 inhibitors e.g. sitagliptin, dapagliflozin Thiazolidinediones e.g. pioglitazone Insulin

Question 26

What drugs cause urinary retention?

Answer 26

Morphine and other opioids. Also anticholinergics (antipsychotics, antidepressants, detrusor relaxants), general anaesthetic, alpha agonists (e.g. clonidine, methyldopa), benzodiazepines, NSAIDs, CCBs, antihistamines, alcohol.

Question 27

What drugs may cause confusion?

Answer 27

Centrally acting drugs such as morphine, anticholinergics, antipsychotics, antidepressants, metoclopramide, anticonvulsants, anti-histamines, corticosteroids, etc.

Question 28

What drugs are eliminated by the kidneys? (adjust dose in renal impairment!)

Answer 28

``` CVS: atenolol, digoxin Neuro: opioids, gabapentin, pregablin, lithium Micro: aminoglycosides, penicillins Haem: LMWH Endo: metformin ```

Question 29

Which drugs should be withheld if patient is dehydrated?

Answer 29

ACE inhibitors/ ARBs, diuretics, NSAIDs, metformin (generally due to risk of AKI and for the latter, lactic acidosis)

Question 30

What drugs lower seizure threshhold?

Answer 30

Opioids, isoniazid, metronidazole, beta-lactams (in toxic dose), buprorpion, TCAs, antipsychotics

Question 31

Should metformin and insulin be continued pre-operatively?

Answer 31

Metformin should be stopped the day before surgery, alongside any insulin. These should be converted to sliding scale insulin/ VRII.

Question 32

What drugs should be stopped pre-operatively?

Answer 32

* ACE inhibitors * Angiotensin 2 antagonists * Consider diuretics * Diabetic Tx * Aspirin, clopidogrel, dipyridamole, warfarin (unless coronary stent) * Lithium * NSAIDs