Chapter 1 + 2 Flashcards
What drugs need to be stopped before surgery?
I LACK OP: Insulin, Lithium, Anticoagulants/antiplatelets,
COCP/HRT, K-sparing diuretics, Oral hypoglycaemics, Perindopril
and other ACE-inhibitors.
List some common enzyme inducers. What effect will this have the drugs.
PC BRAS: Phenytoin, Carbamazepine, Barbiturates, Rifampicin, Alcohol (chronic excess), Sulphonylureas + St Johns wart
It will decrease drug concentration
List some common enzyme inhibitors. What effect will that have on the drug?
AODEVICES:
Amiodarone, Omeprazole,
Disulfiram + diltiazem, Erythromycin!!,
Valproate + verapamil, Isoniazid, Ciprofloxacin + clarithromycin,
Ethanol (acute intoxication),
Sulphonamides
+ grapefruit juice, azoles and azithromycin
What drugs need to be increased before surgery?
Patients on long-term corticosteroids (e.g. prednisolone)
commonly have adrenal atrophy; they are therefore unable to
mount an adequate physiological (‘stress’) response to surgery,
resulting in profound hypotension if the steroids are discontinued. Think sick day rules.
When are antiplatelets/ coagulants CI?
Pts who are bleeding, suspected haemorrhagic stroke, prolonged PT
What are the side effects of steroids? (mneumonic = STEROIDS)
Stomach ulcers, Thin skin, oEdema, Right and left heart failure, Osteoporosis, Infection (including Candida), Diabetes (commonly causes hyperglycaemia and uncommonly progresses to diabetes), and cushing’s Syndrome.
What are the contraindications for NSAIDs?
With NSAIDs the following cautions and contraindications
may be remembered with the mnemonic NSAID: No urine
(i.e. renal failure), Systolic dysfunction (i.e. heart failure),
Asthma, Indigestion (any cause), and Dyscrasia (clotting
abnormality
Side effects of anti-htn?
hypotension
Bradycardia may occur with beta-blockers and some
calcium-channel blockers.
Electrolyte disturbance can occur with angiotensin
converting enzyme (ACE) inhibitors and diuretics
ACE-i = dry cough
BB= worsening of asthma or acute HF
CCB = oedema + flushing
Diuretics = renal failure; thiazide like = bad in gout; potassium sparing = gynaecomastia
What is the fluid of choice for: hypernatraemia hypoglycaemia ascites blood loss
● Is hypernatraemic or hypoglycaemic: give 5% dextrose instead.
● Has ascites: give human-albumin solution (HAS) instead. The
albumin maintains oncotic pressure; furthermore, the higher
sodium content of 0.9% saline will worsen ascites.
● Is shocked from bleeding: give blood transfusion, but a colloid
first if no blood available.
How much fluid should be given a pt with: tachycardia? hypotension? oliguria?
tachycardia/ hypotension: 500ml bolus (250ml in HF) of 0.9% saline
Oliguria: 1 L over 2–4
How much fluid should be given a pt with: tachycardia? hypotension? oliguria?
tachycardia/ hypotension: 500ml bolus (250ml in HF) of 0.9% saline
Oliguria: 1 L over 2–4
What is a reduced UO (oliguria)?
oliguric if <30mL/h; anuric if 0 mL/h –> mL/h; anuric if 0 mL/h)
indicates 500mL of fluid depletion
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When prescribing fluids what you must you check for in pts?
● Check the patient’s U&E to confirm what to give them.
● Check that the patient is not fluid overloaded (e.g. increased
jugular venous pressure (JVP), peripheral and pulmonary
oedema).
● Ensure that the patient’s bladder is not palpable (signifying
urinary obstruction) if giving replacement fluids because of
‘reduced urine output’
What are the CI to LMWH and compression stockings?
Bleeding risk
Arterial or venous disease - risk of worsening and acute limb ischaemia
First vs second line anti emetics? CI?
- Cyclizine 50mg 8 hrly - CI in HF due to fluid retention
2. metoclopramide 10mg 8hrly - CI in Parkinsons and in young women is a risk of acute dystonia
What should you prescribe in mild pain (one regularly and one PRN)
Regular 1g paracetamol 6 hrly
PRN codeine up to 30,g 6 hrly
What should you prescribe in severe pain (one regularly and one PRN)
Co-codamol 30/500 2 tablets 6 hrly (here the 30 is the codeine and the 500 is the paracetamol dose)
morphine PRN 10mg 6 hrly
Neuropathic pain prescription?
the first line of
treatment is amitriptyline (10mg oral nightly) or pregabalin (75mg
oral 12-hourly); duloxetine (60mg oral daily) is indicated in painful
diabetic neuropathy
How do ACE-i cause hyperkalaemia and renal failure?
ACE-inhibitors cause hyperkalaemia through reduced aldosterone production and thus reduced potassium excretion in the kidneys
Causes renal failure as reduces angiotensin-II production necessary for preserving glomerular fltration when the renal blood fow is reduced
How do NSAIDs cause renal failure and ulcers?
Ibuprofen inhibits prostaglandin synthesis needed for gastric mucosal protection from acid.
Ibuprofen inhibits prostaglandin synthesis which reduces renal artery diameter (and blood fow) and thereby
reducing kidney perfusion and function
What should you remember about methotrexate?
Folic antagonist - so CI with trimethoprim due to risk of bone marrow toxicity –> neutropaenic sepsis
Due to risks of neutropenic sepsis if a pt on methotrexate has ?sepsis Withold it.
