Relapse in chronic schizophrenics treated with fluphenazine decanoate is associated with low serum neuroleptic levels.

Seventy-three chronic schizophrenic outpatients were studied for 1 year to determine if neuroleptic drug levels could be useful in preventing relapse. All patients received fluphenazine decanoate i.m., and serum level of neuroleptic was determined by radioreceptorassay. Clinical improvement was measured using the Global Assessment Scale. Results indicate that serum neuroleptic drug levels may be useful in the outpatient management of chronic schizophrenics.