Editor—Wieck and Haddad highlight the fact that hyperprolactinaemia is a common side effect of antipsychotic treatment, but they do not indicate just how often it occurs.1
We have found that three quarters of women and one third of men taking typical antipsychotics have prolactin concentrations above the upper limit of the normal range, and there is a highly significant relation between the dose of antipsychotic treatment and prolactin concentrations.2 Oestradiol and progesterone concentrations were below the lower limit of the normal range in 85% of the women.
This evidence supports the authors' suggestion that antipsychotic induced hyperprolactinaemia is linked to clinically important hypogonadism. Furthermore, preliminary results indicate that over 40% of patients taking prolactin raising antipsychotics show osteopenia associated with hypogonadism (A Meaney et al, proceedings of the British Association of Psychopharmacology, Harrogate, 2001). We are currently measuring bone mineral density in patients taking prolactin sparing antipsychotics, and we hope that this study will address some of the evidence needs raised by Wieck and Haddad.
The authors point out that prolactin sparing atypical antipsychotics offer a new management strategy for antipsychotic induced hyperprolactinaemia. However, there are risks associated with reversing hyperprolactinaemia and hypogonadism, as indicated by reports of unplanned pregnancies after patients changed to prolactin sparing antipsychotics.3 Many of these patients also experienced a relapse of their psychotic illness after the pregnancy. It is important that patients are counselled about the change in fertility associated with changing to a prolactin sparing atypical and given contraceptive advice.
The national service framework has emphasised that patients with severe mental illness have increased physical morbidity and that assessment should include their physical health.4 Wieck and Haddad point to the contribution that endocrine antipsychotic side effects may make to the increased physical morbidity, and these side effects should be monitored.
We recently helped to develop a drug review model that provides patients receiving long term antipsychotic treatment with systematic and periodic assessment of psychopathology, quality of life, and side effects. It is an alternative to the traditional depot clinic style of practice, which often meant that patients took antipsychotics for many years while receiving only ad hoc and limited review. The model represents a move in line with the national service framework towards more proactive patient centred care, and a management approach to the adverse effects of antipsychotics, including the frequently neglected endocrine effects.
References
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