**9. Hyperprolactinaemia in children and adolescents**

There would seem to be an increasing usage of antipsychotic drugs in the treatment of many childhood psychiatric illnesses including attention deficit hyperactivity disorder, bipolar disorder and childhood schizophrenia. In general, it would seem that prolactin levels are elevated in children by the same antipsychotics that induce hyperprolactinaemia in adults (Rosenbloom, 2010). For example, in a recent review, 100% of a cohort of 34 children aged 5-14 years treated with risperidone had prolactin elevation(Rosenbloom, 2010). Prolactin levels were also assessed in a naturalistic study of children and adolescents receiving antipsychotics and in some cases concurrent stimulants (Penzner et al, 2009). This analysis revealed a number of interesting findings, however, the addition of a stimulant did not affect prolactin levels compared to no usage. It had been hypothesised that stimulant treatment may reduce any hyperprolactinaemia induced. Adolescents treated with olanzapine when compared to adults treated in clinical trials are also likely to have greater increases in prolactin levels.

The data on prolactin elevation and longer term outcomes in childhood is clearly complex to obtain. Data however do exist and broadly seem to mirror the findings in adults where hyperprolactinaemia is associated with decreased bone mineral density (O'Keane, 2008). A cross-sectional study of 83 boys aged 7-17 years treated for 3 years with the combination of selective serontonin reuptake inhibitors (SSRIs) and risperidone reported that after adjustments, a negative association was found between bone mineral density at the distal radius and serum prolactin level (Rosenbloom, 2010). The data furthermore was suggestive that this bone mineral density reduction may relate to a direct effect of prolactin on bone turnover as there was no relationship between testosterone levels and prolactin. The risk associated with longer term hyperprolactinaemia can be postulated to be a deleterious effect on peak bone mass attainment (Rosenbloom, 2010).

When considering their prolactin guidelines in 2008, the consensus group concluded that there were two groups in whom prolactin elevation should be avoided where possible. Firstly, in those when peak bone mass has not yet been attained, such as in children and young adults up to the age of 25 years (Peveler et al, 2008) with females being more vulnerable to the adverse effect of prolactin elevation than males. Risperidone is certainly being used in a variety of childhood psychiatric illnesses at young ages. A recent report in a small cohort of patients with conduct disorder (mean age 42 months) treated with risperidone at a mean dosage of 0.78mg/day and a maximum of 1.5mg/day (Ercan et al, 2011) found substantial increase in prolactin from a baseline mean of 5.3 ng/ml to 70 ng/ml at 8 weeks. Six of the eight children who completed the study had hyperprolactinaemia

although all subjects had reduction in prolactin levels, only around half reported improved sexual function (Chen 2011). The reality of the situation is that individual patients will require individual solutions. A physician considering changing an antipsychotic in a stable

There will be patients who are clearly at high risk of prolactin-related adverse events for whom usage of potentially prolactin-elevating antipsychotics needs to be carefully considered,eg, patients with a history of breast cancer or osteoporosis. The other angle to management is to ensure high screening rates for patients at high risk of treatment-emegent osteoporosis and provision of relevant treatment to potentially reduce fracture incidence

There would seem to be an increasing usage of antipsychotic drugs in the treatment of many childhood psychiatric illnesses including attention deficit hyperactivity disorder, bipolar disorder and childhood schizophrenia. In general, it would seem that prolactin levels are elevated in children by the same antipsychotics that induce hyperprolactinaemia in adults (Rosenbloom, 2010). For example, in a recent review, 100% of a cohort of 34 children aged 5-14 years treated with risperidone had prolactin elevation(Rosenbloom, 2010). Prolactin levels were also assessed in a naturalistic study of children and adolescents receiving antipsychotics and in some cases concurrent stimulants (Penzner et al, 2009). This analysis revealed a number of interesting findings, however, the addition of a stimulant did not affect prolactin levels compared to no usage. It had been hypothesised that stimulant treatment may reduce any hyperprolactinaemia induced. Adolescents treated with olanzapine when compared to adults treated in clinical trials are also likely to have greater

The data on prolactin elevation and longer term outcomes in childhood is clearly complex to obtain. Data however do exist and broadly seem to mirror the findings in adults where hyperprolactinaemia is associated with decreased bone mineral density (O'Keane, 2008). A cross-sectional study of 83 boys aged 7-17 years treated for 3 years with the combination of selective serontonin reuptake inhibitors (SSRIs) and risperidone reported that after adjustments, a negative association was found between bone mineral density at the distal radius and serum prolactin level (Rosenbloom, 2010). The data furthermore was suggestive that this bone mineral density reduction may relate to a direct effect of prolactin on bone turnover as there was no relationship between testosterone levels and prolactin. The risk associated with longer term hyperprolactinaemia can be postulated to be a deleterious effect

When considering their prolactin guidelines in 2008, the consensus group concluded that there were two groups in whom prolactin elevation should be avoided where possible. Firstly, in those when peak bone mass has not yet been attained, such as in children and young adults up to the age of 25 years (Peveler et al, 2008) with females being more vulnerable to the adverse effect of prolactin elevation than males. Risperidone is certainly being used in a variety of childhood psychiatric illnesses at young ages. A recent report in a small cohort of patients with conduct disorder (mean age 42 months) treated with risperidone at a mean dosage of 0.78mg/day and a maximum of 1.5mg/day (Ercan et al, 2011) found substantial increase in prolactin from a baseline mean of 5.3 ng/ml to 70 ng/ml at 8 weeks. Six of the eight children who completed the study had hyperprolactinaemia

patient must carefully balance the risks and benefits of continued treatment.

**9. Hyperprolactinaemia in children and adolescents** 

(Graham et al, 2011).

increases in prolactin levels.

on peak bone mass attainment (Rosenbloom, 2010).

without clinical symptoms, as stated by the authors. Studies suggest that children are more sensitive to the prolactin elevating adverse effects of antipsychotics and care is needed to keep these to a minimum (Correll, 2011). The second high risk group would include those with a relevant strong family history of breast cancer or osteoporosis.
