Pass the PSA Flashcards
What drugs do you need to stop before surgery?
I LACK OP
- Insulin
- Lithium - day before
- Anticoagulants
- COCP/HRT - 4 weeks
- K-sparing diuretics - day of surgery
- Oral hypoglycaemics
- Perindopril and other ACE inhibitors
What is the mnemonic helps you to remember to prescirbe the essentials of prescribing?
PReSCRIBER
- Patinet details
- Reaction
- Sign the front of the chart
- Contraindications
- Route
- IV fluids
- Blood clot prophylaxids
- AntiEmetic
- Pain Relief
What are two common drugs that both contain penicillin?
- Co-amoxiclav
- Tazocin
What are the four most common contraidications to be aware of?
- Drugs that increase bleeding shouldn’t be given to patients who are bleeding.
-
Steroid side effects
- Stomach ulcers, Thin skin, Edema, Right and left heart failure, Osteoporosis, Infection, Diabetes, Cushing Syndrome
-
NSAIDs safety considerations
- No urine, Systolic dysfunction, Asthma, Indigestion, and Dyscrasia
- Side effects for antihypertensives
What are the side effects for hypertensives?
- Hypotension (including the earliest symptom, postural hypotension)
-
Dividing the groups of antihypertensives into two mechanistic categories:
- Bradycardia may occur with beta-blockers and some calcium-channel blockers.
- Electrolyte disturbance can occur with ACE-inhibitors and diuretics
- Individual drug classes have specific side effects:
- ACE-inhibitors can result in a dry cough.
- Beta-blockers can cause wheeze in asthmatics; they can also cause worsening of acute heart failure (but help chronic heart failure).
- Calcium-channel blockers can cause peripheral oedema and flushing.
- Diuretics can cause renal failure. Thiazide diuretics (e.g. bendroflumethiazide) can also cause gout, and potassium-sparing diuretics (e.g. spironolactone) can also cause gynaecomastia.
Which fluid do you given during replacement?
What do you give in different situations?
Give all patients 0.9% saline (normal saline, a crystalloid) unless the patient:
-
Is hypernatraemic or hypoglycaemi
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 crystalloid first if no blood available.
How much fluid do you need to give to a patient requiring replacement fluid?
- If tachycardic or hypotensive give 500 mL bolus immediately (250 mL if history of heart failure) then reassess patient.
- If only oliguric (and not due to urinary obstruction (e.g. an enlarged prostate)) then give 1L over 2–4 h then reassess patient.
How can you roughly predict how fluid depleted a patient is?
It is possible to roughly predict how fluid-depleted an adult patient is by using their observations and knowing which are affected first:
- Reduced urine output (oliguric if <30 mL/h; anuric if 0 mL/h) indicates 500 mL of fluid depletion
- Reduced urine output plus tachycardia indicates 1 L of fluid depletion
- Reduced urine output plus tachycardia plus shocked indicates >2 L of fluid depletion.
What is the maximum rate of infusion for IV potassium?
10 mmol/hour
How much maintenance fluid is needed for patients?
- As a general rule, adults require 3 L IV fluid per 24 hours and the elderly require 2 L.
- Adequate electrolytes are provided by 1 L of 0.9% saline and 2 L of 5% dextrose (1 salty and 2 sweet).
- To provide potassium, bags of 5% dextrose or 0.9% saline containing potassium chloride (KCl) can be used but this should be guided by urea and electrolyte (U&E) results; with a normal potassium level, patients require roughly 40 mmol KCl per day (so put 20 mmol KCl in two bags).
How fast do you give fluids to a patient?
- If giving 3 L per day = 8-hourly bags (24 ÷ 3).
- If giving 2 L per day = 12-hourly bags (24 ÷ 2).
- Prescribing fluids in real life, you must:
- 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 class of drug is metoclopramide?
Who should this be avoided in?
- Dopamine antagonist antiemtic
- Parkinson’s disease
- Young women, due to the risk of dyskinesia
What is a good first line antiemtic?
When should this not be used?
What else should be used?
- Cyclizine 50mg
- Not used for cardiac cases (as it can worsen fluid retention)
- Metoclopramide 10mg instead
When patients weigh less than 50kg what is the MAXIMUM dose of paracetamol?
500mg 6-hourly
What electrolyte disturbances does an ACE ibhibitor and thiazide diuretic cuase?
- ACE inhibitor - hyperkalaemia
- Thiazide diuretic - hypokalaemia
What are two common drugs common to causing indigestion?
- NSAID
- Steroid
What class of drug is oxybutinin?
Antimuscarinic
What age group is oxybutinin more potent in?
- Elderly
Can cause confusion
What antiemtic can cause drowsiness?
- Cyclizine
Which drugs should be used with caution with methotrexate?
NSAIDS
What is the mechanism of action of trimethorpim?
Folate antagonist
When there is active infection which drug should be stopped?
Why can this be done?
- Methotrexate
- Has a long half life
What is a side effect of calcium-channel blockers?
Peripheral oedema
What two blood pressure lowering medications should never be given together?
Calcium channel blocker and beta blocker
What is the correct route of administration for all insulin except a sliding scale?
SC
WHAT DO YOU DO TO THE LEVOTHROXINE DOSE WITH THE FOLLOWING TFT RESULTS?
- TSH <0.5 - Decrease dose
- TSH 0.5-5 - Same dose
- TSH >5 Increase dose
What are examples of drugs which need to be monitored?
- Digoxin
- Theophylline
- Lithium
- Phenytoin
- Gentamicin
- Vancomycin
How much Gentamicin will a patient recieve?
When is this changed?
What will happen then?
- 5-7mg/kg once daily
- In patients with severe renal failure or endocarditis
- Divided into TWO daily doses
- What time do you check the gentamicin dose?
- When is this not used?
- What is used instead?
- 6-14h
- In divided dosing
- 1hr post dose + through (just before next dose)
- What product in paracetamol poisioning is toxic?
- What product is needed to convert NAPQI into a non-toxic substance?
- NAPQI
- Glutathione
What are the vitamin K clotting factors?
2, 7, 9, and 10
What do you do in a major bleed while on warfarin?
- Stop warfarin
- Give 5-10 mg IV vitamin K
- PRothrombin complex (e.g. Beriplex)
What drugs are used to correct ECG changes in AF?
- Beta-blockers - not in asthmatics
- Diltiazem - can worsen fluid retention
- Digoxin
WHAT IS THE APPROPRIATE THERAPY FOR CELLULITIS?
500mg flucloxacillin 6 hourly for 7 days
What is the appropriate therapy for CHF?
IV furosemide 40mg IV
Which two drugs can cause side effects such as dry mouth and double vision?
- Cyclizine
- Amitriptyline