There is a blood test that can be done to measure the level of clozapine in your daughter's system. This test is in addition to the bloodwork done to measure her WBC, which is probably done bi-weekly or monthly and needed to fill her clozapine prescription.
I have been on clozapine for the past 3 yrs and am at a dose of 200 mgs, down from a high of 450 mgs.
Are you sure that your daughter is taking her medication? I know that although the clozapine helps clear my thinking, I still hate the fatigue that comes along with it!!! Sometimes I do play around with my dose, without my Drs. knowledge (very bad idea) and I do have a return of symptoms.
Try to make sure your daughter is taking her medication regularly and have her contact the dr if she is having a return of symptoms. There are other medications that can be added to the clozapine to help her overall. I take a couple of anti-depressants and provigil that help me cope.
Take care and keep me posted

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