First-episode
psychosis (
FEP) patients are more sensitive to
neuroleptic side-effects such as
hyperprolactinemia. We examined the
prolactin levels of previously minimally treated patients with first episode
schizophrenia over their first year of treatment with
flupenthixol decanoate and the relationship between
prolactin levels, gender and clinical features of
schizophrenia.
Prolactin levels were assessed at three monthly intervals in 126 patients with first-episode
schizophrenia in a single-site study conducted over 12 months during treatment with
flupenthixol decanoate according to a fixed protocol. The mean
prolactin level for the total sample was 11.91 ng/ml (standard deviation [SD]15.52) at baseline. Women had higher levels of
prolactin than men at month 3, 6 and 12, reaching statistical significance at month 12 (p = 0.02). At 12 months more women than men had
hyperprolactinemia (defined as more than 20 ng/ml for males, and as more than 25 ng/ml for females (p = 0.007). Using a mixed effect model, there was a significant association between
prolactin change scores over 12 months and gender (p = 0.025) as well as Positive and Negative Syndrome Scale (PANSS) total scores (p = 0.001). In addition female gender (p = 0.04) and age (p = 0.02) correlated with the risk of
hyperprolactinemia as categorical variable. In this study treatment with
flupenthixol decanoate was associated with relatively low levels of
hyperprolactinemia, likely owing to
flupenthixol's relatively atypical mode of action, as well as to the low doses used in our study. We found an inverse correlation between total PANSS scores and
prolactin levels, which could support the suggested theory of
prolactin having
antipsychotic properties. Our study confirms the importance of gender on the
prolactin raising effects of
antipsychotic treatment.