Clozapine
What this test measures
Clozapine is an antipsychotic medicine with a level that varies a great deal between people, and is affected by smoking and infection. The level is measured to guide the amount taken.
Why doctors request it
Checked by mental health teams when starting, when smoking habits change, during infections, and when side effects occur.
What commonly pushes it up
- Stopping smoking, which can raise the level sharply within days
- Infections and inflammation
- Some antibiotics and other medicines as a class
- Caffeine
What commonly pushes it down
- Starting or restarting smoking
- Missed tablets
- Some medicines as a class that speed its breakdown
Everyday reasons for a value outside the range
- A change in smoking is the commonest reason for a big shift
- The norclozapine value printed alongside is a breakdown product
About the sample
Just before the morning tablet, about 12 hours after the last one.
Upload a photo or PDF and see every line against the range your lab printed, explained in plain English. First report free.
Read my report freeThis is an educational summary of results you uploaded. It is not medical advice, a diagnosis or a treatment plan, and it does not replace the doctor who requested the test. If you are worried, or a result is marked outside range, discuss it with your doctor. Written and reviewed by a UK consultant physician. Reference ranges vary between laboratories.