Depot neuroleptic medication and serum levels by radioreceptor assay: prolactin concentration, electrocardiogram abnormalities and six-month outcome.

Twenty-six chronic schizophrenic patients on well-established depot neuroleptic regimes with stable doses (16 on fluphenazine decanoate, 10 on flupenthixol decanoate) had serum neuroleptic levels measured by radioreceptor assay (RRA) and were followed for six months. The serum prolactin (PRL) concentration and resting electrocardiogram (ECG) were also taken at the beginning of the study period. Correlations had previously been noted between RRA measured neuroleptic levels and outcome in both acute and chronic patients on oral medication. However, in this study of depot medication no significant correlations were found between serum neuroleptic concentration, serum prolactin concentration and the clinical state or outcome. The prevalence (33%) and type of ECG abnormality observed was similar to that previously reported.