Psychiatry

Question 1

How is clozapine metabolized?

Answer 1

Metabolized by CYP1A2.

Cigarette smoking induces CYP1A2 therefore tobacco smokers may require twice the dose of clozapine.

Theophylline, ciprofloxacin and fluvoxamine and smoking cesseation can decrease the metabolism of clozapine and may produce clinical toxicity.

Question 2

When is the risk of developing agranulocytosis highest in patients taking clozapine?

Answer 2

Occurs in 1% of patients. Highest risk around 3 months into the treatment. Needs weekly blood tests for 18 weeks.

Question 3

Why should you avoid tyramine containng food when you are taking MAOI?

Answer 3

Tyramine is usually metabolized by MAO-A.
If MAO-A is inhibited by MAOI and tyramine is ingested, tyramine can induce release of stored monoamines such as dopamine, noradrenaline and epinephrine, resulting in hypertensive crisis.

Question 4

What is the difference between atypical and typical antipsychotics?

Answer 4

Both block D2 receptors - however atypical antipsychotics inhibit serotonin receptors as well.

Question 5

What is the strongest risk factor for suicide?

Answer 5

Previous history of self harm or suicide attempt.

Question 6

RIsk of atypical antipsychotic use in geriatric population for behavioural control?

Answer 6

Increased risk of strokes and VTE