Clozapine

Question 1

Indication

Answer 1

Resistant schizophrenia

Only used when 2+ antipsychotics including one 2nd generation has been used for 6-8 weeks each

Question 2

After how many missed doses should you refer back?

Answer 2

After two missed doses

Question 3

Side effects of clozapine

Answer 3

MAG

Myocarditis and cardiomyopathy
- report and stop on tachycardia

Agranulocytosis and neutropenia

Gastrointestinal disturbances
- Intestinal peristalsis
- Constipation
- Intestinal obstruction
- Faecal impaction
- Paralytic ileus

Hypotension
Hyperglycaemia
Weight gain

Question 4

Clozapine MHRA warning

Answer 4

Constipation and blood monitoring

• And other antipsychotics; monitoring blood conc. for toxicity when a pt. stops smoking, on interacting medicines, pt has pneumonia, suspected toxicity
• reminder of potentially fatal risk of intestinal obstruction, faecal impaction, and paralytic ileus

Question 5

Monitoring

Answer 5

FBCs (WBCs) - weekly from day 1 to 18 weeks, then fortnightly from week 18, monthly thereafter

Advisable to monitor prolactin at baseline, 6 months, then annually

Close medical supervision during initiation (risk of hypotension and convulsions)

Lipids and weight - at baseline, at 3 months, annually

Fasting blood glucose at baseline, after one months’, at 4-6 months

Question 6

Interactions

Answer 6

Smoking increases metabolism of clozapine

Question 7

Treatment cessation

Answer 7

Risk of relapse if medication stopped after 1-2 years
Gradual withdrawal and closely monitored for relapse
Dose reduction over 1-2 weeks
Monitor for 2 years after withdrawal of antipsychotic signs