Endocrine Abstracts

Hyperprolactinemia is known to have a wide differential with multiple causes including physiological, pathological and pharmacological. Drug induced causes of hyperprolactinemia are myriad however these become significant when prolactin levels rise to proportions that lead to clinical manifestations. We present a case of a 40 years old lady who was referred to endocrinology for an irregular menstrual cycle. Initial investigations revealed a prolactin level of 5767 mIU/l (range 102-496 mIU/l). Prior to the past 1 year, she had regular menstrual cycles after a menarche at the age of 13. No hirsutism was reported. Over the last 1 year she reported menstrual cycles occurring in gaps of 2 and a half months. She further reported galactorrhea for 6 months. Her past medical history only included gastro-esophageal reflux for which she was being followed up by gastroenterology and had been on lansoprazole since the past 1 year. On examination, she had a weight of 70.15 kg, height 152 cm with a BMI of 30 kg/m2. Her BP was 113/73mmHg. Visual fields were normal to confrontation. Palpation of neck revealed no palpable goitre and she was clinically euthyroid. Bloods revealed negative serum HCG, FSH 11 IU/l, Estradiol 494 pmol/l, LH 23.1 IU/l, testosterone 1 nmol/l (range 0-2.8 nmol/l), IGF 1 15.6 nmol/l (range 10.0-38 nmol/l). Pelvic Ultrasound revealed no evidence of polycystic ovaries. MRI Pituitary was reported as normal. Initially recommended a course of cabergoline in view of symptoms, patient had spontaneous resumption of menses following stopping lansoprazole. Prolactin was noted to fall to 117 mIU/l, two months post stopping lansoprazole. Lansoprazole is a commonly prescribed medication; this case report is unique as clinically significant hyperprolactinemia with such high levels of prolactin have not been reported before. Multi-disciplinary management of such cases is essential particularly with a wide variety of non-endocrine specialties prescribing these medications.