General Notes

Question 1

What considerations around women of childbearing age and doxycyline use? [2]
What can you use as an alternative? [1]

Answer 1

• Doxycycline shouldn’t be used in pregnancy
• Shouldn’t be used in breast feeding
• Erythromycin should be used instead

Question 2

Name a side effect of theophylline [1]

Answer 2

Causes tremor

Question 3

Describe the effect of starting ACEin/ARBs on renal function [1]

Answer 3

Get an egfr drop of about 10-30%, but recovers
- Check renal function and serum electrolytes 1–2 weeks after starting treatment and 1–2 weeks after each dose increase.
- Thereafter, check renal function and serum electrolytes annually unless clinical judgement or abnormal blood testing parameters indicate a need for more frequent monitoring.

Question 4

Which drugs do you need to be careful with when giving tetracyclines with? [2]
Why? [1]

Answer 4

Tetracyclines x Fe:
- Reduces the bioavailability and efffiacy of the Abx. Seperate dosing by 2hrs

Question 5

What do you need to be mindful about when prescribing ketoconazole? [1]

Answer 5

Needs to be in absorbed in acidic conditions
- PPI or anti-acid is bad / contraindicated

Question 6

What advise would you give to someone when prescribing flucoxacillin or penicillin? [1]

Answer 6

Need to be d as they bind to food and reduce absorbtion

Question 7

The mnemonic [] can be used to easily remember common CYP450 inhibitors.

Answer 7

The mnemonic SICKFACES.COM can be used to easily remember common CYP450 inhibitors.

Sodium valproate
Isoniazid
Cimetidine
Ketoconazole
Fluconazole
Alcohol & Grapefruit juice
Chloramphenicol
Erythromycin
Sulfonamides
Ciprofloxacin
Omeprazole
Metronidazole

Question 8

The mnemonic [] can be used to easily remember common CYP450 inducers.

Answer 8

Cytochrome P450 Inducers
CYP450 inducers reduce the concentration of drugs metabolised by the CYP450 system.

The mnemonic CRAP GPs can be used to easily remember common CYP450 inducers.

Carbemazepines
Rifampicin
Alcohol
Phenytoin
Griseofulvin
Phenobarbitone
Sulphonylureas

Question 9

Common Interactions
Exampled of drugs that commonly interact with CYP450 enzyme inhibitors and inducers are;

Answer 9

Warfarin
the Combined Contraceptive Pill

Theophylline
Corticosteroids
Tricyclics
Pethidine
Statins
Codeine
Selective serotonin reuptake inhibitors (SSRI): sertraline, citalopram, fluoxetine

Question 9

Which are common PSA DDI that need to be aware of? [5]

Answer 9

1. Warfarin + inducer → ↓ INR
- e.g., starting rifampicin, carbamazepine, or phenytoin in a patient stable on warfarin → INR drops → clot risk.
PSA answer: Increase warfarin dose + recheck INR sooner.

2. COCP + rifampicin → contraceptive failure
- PSA loves this one.
- ONLY rifampicin / rifabutin cause this.
PSA answer: Use alternative contraception or switch antibiotic.

3. Antiepileptics interacting with each other
* Carbamazepine or phenytoin inducing the metabolism of other AEDs → loss of seizure control.
* PSA answer: Monitor levels / adjust dose.

4. Steroids or immunosuppressants + rifampicin
- e.g., Prednisolone, ciclosporin, tacrolimus
→ Levels fall → transplant rejection or adrenal issues.
PSA answer: Increase dose + monitor levels.

5. Anti-HIV drugs + rifampicin
-Rifampicin ↓ protease inhibitor levels markedly.
PSA answer: Avoid combination — switch TB antibiotic.

Question 10

What is standard LMWH prophylaxis dose? [1]

Answer 10

Standard: 40 mg SC daily
- Renal impairment: reduce dose

Question 11

In Basal/Bolus insulin regimes - what are the names for the long [2] and short [2] acting insulin drugs?

Answer 11

Basal–bolus:

Lantus/Levemir = long-acting

NovoRapid/Humalog = rapid

Question 12

How would you change UTI tx if there is renal impairment? [1]

Answer 12

AVOID NITROFURANTION
- Give trimethoprim instead

NB: TRIM for trickey kidneys

Question 13

How do you alternate / decide which DOACs to use in AKI? [

Answer 13

If eGFR < 30 → safest approach in exam is stop DOAC or switch to warfarin, except maybe apixaban in some guidelines.

Question 14

Give three abx that are safe in pregnancy [3]

Answer 14

penicillins, cephalosporins, erythromycin

Question 15

Which drugs interact with Lithium that need to think about? [3]

Answer 15

Eliminated almost entirely by kidneys.

Thiazide diuretics → ↑ lithium levels (↓ excretion)

ACE-i / ARBs → ↑ lithium levels

NSAIDs → ↑ lithium levels

Monitor: serum lithium + renal function

Question 16

What is the combination effect of NSAIDs X ACEin? [1

Answer 16

Combined effect:

NSAIDs can blunt the blood pressure-lowering effect of ACE-i.

In combination with diuretics, there’s a triple whammy → high risk of AKI.

Question 17

What are sick day rules for DMT2?

Answer 17

Do not stop insulin → continue basal and correction doses.

Stop certain oral medications temporarily:

Metformin → stop if at risk of dehydration or AKI (vomiting, diarrhoea)

SGLT2 inhibitors (e.g., empagliflozin, dapagliflozin) → stop to prevent DKA

Sulfonylureas → may continue, but risk of hypoglycaemia if eating poorly

Monitor blood glucose more frequently → at least 2–4 hourly.

Question 18

What do you need to bear in mind with regards to long term phenytoin regimes? [1]

Answer 18

It has zero order kinetics:
- small increases can cause disproportionate rises in plasma concentration → toxicity risk.

Question 19

How do you manage DMT2 drugs if undergoing surgery/ [4]

Answer 19

Metformin
- Stop on the day of surgery

SGLT2 In:
- Hold two days before

Insulin:
- Continue long acting, reduce dose by 20-50%
- Hold short acting

Question 20

Which laxative should you use for fecal impaction? [1]

Answer 20

Macrogol

Question 21

What is the resus bolus in children? [1]

Answer 21

20mL/kg

Question 22

Whats the dose and max. dose for naloxone? [1]

Answer 22

400 micrograms up to 2mg

Question 23

Describe when you give NAC for paracetamol OD? [4]

Answer 23

Acetylcysteine should be given if:
* the plasma paracetamol concentration is on or above a single treatment line joining points of 100 mg/L at 4 hours and 15 mg/L at 15 hours, regardless of risk factors of hepatotoxicity

• there is a staggered overdose or** there is doubt over the time of paracetamol ingestion**, regardless of the plasma paracetamol concentration; or
• patients who present 8-24 hours after ingestion of an acute overdose of more than 150 mg/kg of paracetamol even if the plasma-paracetamol concentration is not yet available
• patients who present > 24 hours if they are clearly jaundiced or have hepatic tenderness, their ALT is above the upper limit of normal
• acetylcysteine should be continued if the paracetamol concentration or ALT remains elevated whilst seeking specialist advice

Question 24

How quickly is NAC given for paracetamol OD? [1]

Answer 24

Acetylcysteine is now infused over 1 hour

Question 25

Which drugs can't you give charcoal for in acute OD? [2] What would you give instead? [1]

Answer 25

NOT for substances that do not bind to charcoal * Methanol * Iron * Lithium * Ethylene glycol * Strong acids and alkalis ## Footnote **Gastric lavage:** * Indicated only for iron, lithium * Needs endo-tracheal intubatio

Question 26

Haemodialysis can be considered for severe poisoning with drugs having low volume of distribution. This includes [4]

Answer 26

Aspirin * Toxic alcohols * Lithium * Valproate

Question 27

A 75-year-old man took an overdose of his amitriptyline. How do you tx? [1]

Answer 27

Sodium bicarbonate 50mmol intravenously

Question 28

Describe Mx of TCA OD [2]

Answer 28

Tricyclic antidepressant overdose - Treatment is generally supportive * **If acidotic or QRS widening** * give intravenous sodium bicarbonate

Question 30

What is a usual toxic dose for paracetamol OD? [1]

Answer 30

* Toxic dose normally >150mg/kg in 24h

Question 31

What should you monitor for in Paracetamol OD? [+]

Answer 31

Monitor INR, ALT, creatinine and liver tenderness pre- and post treatment

Question 32

Describe the tx plans for paracet. OD for: - 0-8hrs - 0-24hrs - > 24hrs

Answer 32

**Paracetamol overdose (0-8h)** * If the patient presents around 4-8h after ingestion, measure paracetamol levels immediately and commence NAC if levels above the treatment line or if there is evidence of biochemical liver injury **Paracetamol overdose (8-24h)** * Measure paracetamol levels * Start full treatment of intravenous N-acetylcysteine (immediately, even before plasma levels available if dose unclear/ estimated >150 mg/kg) * Stop treatment if below the treatment line and no evidence of biochemical liver injury i.e. elevated ALT or INR; **Paracetamol overdose (>24h)** * Give full treatment of N-acetylcysteine intravenously if ingested >150mg/kg/unkown dose, are * jaundiced or have hepatic tenderness * If measurable paracetamol at 24h, likely very large OD, give full treatment of N-acetylcysteine * If INR < 1.3, ALT within normal range, unmeasurable paracetamol and asymptomatic, then no treatment require **Paracetamol overdose (staggered)** * If >150mg/kg paracetamol taken over >1h period (within 24h), give full treatment of intravenous N-acetylcysteine

Question 33

Describe how you tx aspirin OD [+]

Answer 33

**Activated charcoal can be given within 1 hour of ingesting more than 125 mg/kg of aspirin** Plasma salicylate concentration can guide treatment / prognosis * If metabolic acidosis, give sodium bicarbonate (50-100 mmol); aim urine pH 7.5-8.5, blood pH< 7.55 * If >500mg/L, give 225 mmol sodium bicarbonate * If >700mg/L, consider haemodialysis * If coma, seizures, pulmonary oedema, renal failure, consider haemodialysi

Question 34

What can you give to resverse acute dystonias? [1]

Answer 34

Procyclidine

Question 35

Beta-blocker poisoning [2]

Answer 35

Glucagon Atropine

Question 36

Iron poisoning?

Answer 36

Desferioxamine mesilate

Question 37

Which drugs commonly are hepatoxic? [+]

Answer 37

Statins Aziothropine Amiodarone Anti TB drugs (RIPE) Abx

Question 38

Which drugs commonly are cause QTc prolongation? [+]

Answer 38

**A A**ntiarrhythmics (Class Ia & III: Quinidine, Procainamide, Amiodarone, Sotalol) **B** Anti**B**iotics (Macrolides: Erythromycin, Clarithromycin; Fluoroquinolones: Ciprofloxacin, Levofloxacin) **C C**NS drugs: Antipsychotics (Haloperidol, Quetiapine), Antidepressants (Citalopram, Amitriptyline) **D D**roperidol / Domperidone (antiemetics) **E E**lectrolyte-impacting / “everything else”: Methadone, some antifungals (Fluconazole)

Question 39

Which anti-emetic would you give first line? Why not others? When would you not use this one?

Answer 39

**Ondansetron** is usually first-line, especially IV in hospital or perioperative patients. - **Cyclizine** has euphoric feeling - risk of abuse AND caution with BPH as causes retention Can also be used in PD as doesnt cross BBB Risk of QTC prolongation

Question 40

Which drugs classically cause agranulocytosis? [4]

Answer 40

Carbimazole MTX Phenytoin Clozapine

Question 41

What are the two types of HIT? [2]

Answer 41

Question 42

Describe the different regimens for warfarin reversal [+]

Answer 42

**Major bleeding** —**stop warfarin sodium; give phytomenadione (vitamin K1) by slow intravenous injection; give dried prothrombin complex** (factors II, VII, IX, and X); if dried prothrombin complex unavailable, fresh frozen plasma can be given but is less effective; recombinant factor VIIa is not recommended for emergency anticoagulation reversal **INR >8.0, minor bleeding**—stop warfarin sodium; give phytomenadione (vitamin K1) by slow intravenous injection; repeat dose of phytomenadione if INR still too high after 24 hours; restart warfarin sodium when INR < 5.0 **INR >8.0, no bleeding**— stop warfarin sodium; give phytomenadione (vitamin K1) by mouth using the intravenous preparation orally [unlicensed use]; repeat dose of phytomenadione if INR still too high after 24 hours; restart warfarin when INR < 5.0 **INR 5.0–8.0, minor bleeding**—stop warfarin sodium; give phytomenadione (vitamin K1) by slow intravenous injection; restart warfarin sodium when INR < 5.0 **INR 5.0–8.0, no bleeding**—withhold 1 or 2 doses of warfarin sodium and reduce subsequent maintenance dose **Unexpected bleeding at therapeutic levels**—always investigate possibility of underlying cause e.g. unsuspected renal or gastro-intestinal tract pathology

Question 43

Which side effects should you be aware for when giving Linezolid [2]

Answer 43

Question 44

A patient has CKD and has been prescribed digoxin. What do you need to do and why? [1]

Answer 44

**You need to check digoxin serum levels** if they present with Sx of toxicity: **N&V, blurred vision & confusion** - CKD increases the liklihood of toxcity bc causes hypokalaemia.

Question 45

How would you prescribe fluids if a DMT1 patient is having surgery and has been placed on VR insulin? [1]

Answer 45

Need 0.45% NaCl (with KCl and 5% dextrose)

Question 46

Describe the insulin mx for DM patients: - on the day before the surgery - on the day of surgery and throughout intra-operative period - on the day of the surgery

Answer 46

**on the day before surgery**: - **once daily long-acting insulin analogues** should be **given at 80 %** of the **usual dose**; otherwise the patient’s usual insulin should be given as normal; **on the day of surgery and throughout the intra-operative period**: - **once daily long-acting insulin analogues should be continued at 80 % of the usual dose** - all other insulin should be stopped until the patient is eating and drinking again after surgery; **on the day of surgery:** - **start an intravenous substrate infusion of potassium chloride with glucose and sodium chloride (based on serum electrolytes which must be measured frequently)** - and infuse at a rate appropriate to the patient’s fluid requirements. To prevent hypoglycaemia, this infusion must not be stopped while the insulin infusion is running; - **a variable rate intravenous insulin infusion of soluble human insulin in sodium chloride 0.9 %** (made either according to locally agreed protocols or using prefilled syringes) should be given via a syringe pump at an initial infusion rate determined by bedside capillary blood-glucose measurement. (made either according to locally agreed protocols or using prefilled syringes) should be given via a syringe pump at an initial infusion rate determined by bedside capillary blood-glucose measurement.

Question 47

A DM patient having surgery. They're on VRI. Their glucose is found to be 5. What would you prescribe them? [1]

Answer 47

**intravenous glucose 20 % should be given** if blood-glucose drops below 6 mmol/litre, and blood-glucose checked every hour, to prevent a drop below 4 mmol/litre. If blood-glucose drops below 4 mmol/litre, intravenous glucose 20 % should be adjusted and blood-glucose checked every 15 minutes, until blood-glucose is above 6 mmol/litre (testing can then revert to hourly). If blood-glucose rises above 12 mmol/litre, check ketones and consider other signs of diabetic ketoacidosis.

Question 48

Describe the amount of K in 500ml of 0.15% and 0.3% KCl (and then how quickly you could give)

Answer 48

0.15% KCl 500 mL = **10 mmol** → can be given over ~1 hour via peripheral line safely. 0.3% KCl 500 mL = **20 mmol** → can be given over ~1 hour via central line, or slower via peripheral.

Question 49

If you had severe hyperkalaemia without ECG changes what would you prescribe? [1]

Answer 49

Actrapid 10-20 units in 100ml of 20% flucose in 5-15mins