Flupenthixol in depression. A study of serum levels and prolactin response

The relationship between improvement in symptomatology and changes in prolactin and serum cis-flupenthixol levels has been evaluated in 16 patients with a clinical diagnosis of depression, who were treated with 1 or 2 mg of flupenthixol in a once daily morning dose. No significant differences in clinical response were noted between those on 1 and 2 mg, and side effects were few. The presentation of some side effects, in particular extrapyramidal symptoms, were related to higher serum levels and prolactin levels particularly in the early stages of the study. Improvements in depressive symptoms were unrelated to serum levels, but at day 56 of the trial were positively correlated to changes in prolactin levels. Improvements in anxiety symptoms were positively related to serum levels at day 3 but negatively related at day 56. These results are discussed in the light of possible influences of dopamine antagonism in relation to an antidepressant effect.