Psych: Clozapine

Question 1

What is clozapine?

When is it used?

Answer 1

Antipsychotic medication used in cases of treatment resistant schizophrenia.

This is those who have not responded to treatment with at least two other antipsychotics (or not tolerated other medications).

Question 2

Advantages of clozapine?

Answer 2

6/10 people with treatment-resistant schizophrenia will benefit from taking clozapine.

Improvement in symptoms associated with schizophrenia.

Question 3

Common side effects of clozapine?

Answer 3

1) Any new medication: tummy upset, nausea, abdo pain

2) Constipation: advise high fibre diet, laxatives

3) Weight gain: advise healthy lifestyle

4) Hypersalivation

5) Tachycardia

6) Hyperglycaemia

Question 4

What are 4 rare but serious side effects of clozapine?

Answer 4

1) Lowers seizure threshold

2) Agranulocytosis –> seek medical help if develop flu-like symptoms e.g. fever

3) Bowel obstruction/perforation due to constipation

4) Myocarditis/cardiomyopathy –> seek help if chest pain, palpitations etc

Question 5

What baseline investigations are required prior to starting clozapine?

Answer 5

1) ECG

2) BP & pulse

3) BMI

4) Labs: FBC, U&Es, LFTs, prolactin, HbA1c and lipids. For clozapine, a baseline troponin is also requested.

Question 6

What monitoring is required after starting clozapine?

Answer 6

FBC monitoring:
- weekly for first 18 weeks
- then fortnightly
- then monthly after a year

Question 7

What social factor can affect clozapine levels?

Answer 7

Smoking –> smoking can lower clozapine levels