Normalization of hyperprolactinaemia after withdrawal of a low dose of amisulpride.

Hyperprolactinaemia is an important but neglected adverse effect of antipsychotic medication [1]. It occurs frequently with conventional antipsychotics and some atypical antipsychotics (risperidone and amisulpride). We found hyperprolactinaemia in all 10 patients evaluated during therapy with low doses (50 mg per day) of amisulpride used as an augmentation to antidepressant treatment, benzodiazepines or in monotherapy [2]. We decided to suspend amisulpride treatment for patients in which no clinical benefits were observed. Plasma prolactin levels were measured in 3 women and 2 men (mean age 44±13.5 years) with depressive symptoms who were treated with 50 mg of amisulpride per day as an augmentation to antidepressants (n=3) or benzodiazepine anxiolytics (n=3) for a median of 61 days. Informed consent was obtained from all subjects. The prolactin plasma assessment was the same as in our previous study [2]. The normal range established for prolactin assay is within 1.39–24.2 ng/ml. All patients had hyperprolactinaemia (range 39.8–200 ng/ml). Only one woman suffered from amenorrhea that was possibly induced by amisulpride use. All patients were reassessed after 7–24 days (median 10 days) of the amisulpride withdrawal. There was a significant decrease of prolactin levels (Wilcoxon matched pair test, Z = 2.02, p=0.043) from the median 91.9 ng/ml (±95% CI 22–188) to the median 17.5 ng/ml (±95% CI =–18–95). Two of the five patients continued to have hyperprolactinaemia (119 ng/ml and 27 ng/ml) after 10 and 7 days of amisulpride withdrawal. It seems that the median of 10 days after withdrawal of a low doses amisulpride is sufficient to show a significant decrease of the prolactin level but the period of 10 days is insufficient to achieve euprolactinaemia in all of the patients. From a research point of view, it is valuable to follow prolactin plasma levels after withdrawal of amisulpride monotherapy in future studies. In our opinion the data from our small sample have clinical importance due to the lack of information concerning the time profile of prolactinaemia change following cessation of a low dose of amisulpride.