Galactorrhoea, hyperprolactinaemia, and pituitary adenoma presenting during metoclopramide therapy

A 49-year-old woman presented with a one month history of headaches, loss of libido and galactorrhoea. She had been taking metoclopramide for the previous 3 months for reflux oesophagitis. She was found to have substantially elevated serum prolactin levels and a pituitary adenoma, which have not been previously described in a patient taking metoclopramide. The drug was stopped and the serum prolactin level fell progressively to normal with resolution of symptoms over 4 months. This suggested that contrary to our original impression that she had a prolactin-secreting pituitary adenoma which had been stimulated by metoclopramide, she had metoclopramide-induced hyperprolactinaemia and an incidental pituitary tumour.