MRCP Toxicology

Question 1

Management of CO poisoning

Answer 1

Immediate: Tight fitting non-rebreather, 15L
More definitive (but takes longer to arrange): hyperbaric oxygen

Question 2

Drugs at risk of causing SNHL

Answer 2

IV gentamicin
IV vancomycin
IV erythromycin
IV furosemide (NOT oral)

Question 3

What type of receptor does amlodipine block

Answer 3

L-type calcium channels

hypotensive and tachycardic in overdose

Question 4

Mechanism behind steroids causing raised blood glucose/diabetes

Answer 4

Increased gluconeogenesis

Question 5

Pharmacological treatment of neuroleptic malignant syndrome

Answer 5

SC bromocriptine

Question 6

Drugs that can precipitate psoriasis

Answer 6

Lithium
Beta blockers
NSAIDs
Anti-malarials

Question 7

Therapy for RA in pregnancy

Answer 7

Sulfasalazine

azathioprine second line

Question 8

Antipsychotic responsible for agranulocytosis

Answer 8

Clozapine

Question 9

Safest anti-epileptic in pregnancy

Answer 9

Lamotrigine

Question 10

Early test to confirm testosterone abuse

Answer 10

Urinary testosterone/epitestosterone ratio

Question 11

Antidote to beta blocker overdose

Answer 11

Glucagon (treats hypotension and hypoglycaemia)

Question 12

Renal abnormality seen in solvent abuse (glue/aerosol sniffing)

Answer 12

Distal renal tubular acidosis

Question 13

Young boy (?bodybuilder ?gay) comatose, spontaneously wakes up and removes own ETT 3h later

Answer 13

GHB overdose

• abused for weight loss & body building
• tastes like seaweed
• rapid reversal of coma
• charcoal within 1h. otherwise supportive measures

Question 14

Hyponatraemia secondary to ecstasy intoxication (normal neurology & GCS)

Answer 14

Fluid restriction
(hypertonic saline considered if reduced GCS and seizures)

Question 15

Management of calcium channel overdose

Answer 15

Give calcium!

Question 16

Allopurinol + Azathioprine =

Answer 16

Myelosuppression
Xanthine oxidase inhibition (allopurinol) and azathioprine cause formation of mercaptopurine metabolites due to elevated 6-mercaptopurine (major metabolite of azathioprine)

Question 17

Describe amiodarone induced thyrotoxicosis type 2

Answer 17

Destructive thyroiditis, decreased blood flow & decreased uptake on scan.
Poorly responsive to medication, often burns itself out

Question 18

Check TPMT activity prior to starting which drugs?

Answer 18

Azathioprine

Mercaptopurine

Question 19

Symptoms of salicylate toxicity

Answer 19

Bilateral deafness, tinnitus, visual blurring, vomiting
Initially respiratory alkalosis then severe metabolic acidosis
Urinary alkalinisation

Question 20

Pathophysiology of sodium bicarb in TCA OD

Answer 20

Cardioprotective - reduces TCA binding to myocardium

Question 21

SOB, abdo pain, hypoxia, hypotension following sodium nitroprusside

Answer 21

Cyanide poisoning

- sodium nitroprusside denatures to form cyanide

Question 22

Monitoring whilst on azathioprine

Answer 22

FBC, U&E, LFT

Question 23

When is sodium bicarb indicated in TCA OD?

Answer 23

QTc >100 (decreases risk of seizures/arrhythmias)

Question 24

Treatment of LA toxicity

Answer 24

20% lipid emulsion (bolus then infusion)
- symptoms of LA toxicity:
peri-oral paraesthesia, slurred speech, altered mental status, seizures