Summary

A middle-aged woman was referred under the 2-week urgent brain cancer initiative following the finding of a raised serum prolactin level. The patient had been taking metoclopramide on a daily basis to aid her symptoms of irritable bowel syndrome. The raised prolactin level had led to oligomenorrhoea prompting her general practitioner (GP) to check pituitary hormone levels.

Metoclopramide is a potent dopamine antagonist and dopamine acts as the physiological inhibitor of prolactin synthesis. Thus, the dopamine antagonism led to elevated prolactin level and the symptom of oligomenorrhoea.

Following curtailment of the metoclopramide, the prolactin level normalised very quickly and the patient was reassured.

Consideration should be given to non-pathological causes of hyperprolactinaemia, including physiological states such as pregnancy and concurrent medication.