LAUSR

Background: A mild increase in prolactin has been previously reported in patients with pathological conditions, such as ESRD, as well as with several medications. Typically this is a mild elevation (<100 ng/mL), though certain medications have been shown to increase prolactin up to 200 ng/mL. However, we report a case of severe hyperprolactinemia in a patient with ESRD and on medications known to cause mild prolactin elevations. Clinical Case: Our patient is a 35-year-old female presenting for hyperprolactinemia. She has a history of uncontrolled diabetes with complications of ESRD on iHD, gastroparesis, and neuropathy. Further history revealed galactorrhea for 15 years following the birth of her second child as well as amenorrhea for the last 1.5 years. At the time of evaluation, she was not breastfeeding and did not have any reported life stressors. Medications were unchanged and included metoclopramide 10 mg daily and promethazine 25 mg PRN. Initial prolactin level one year prior to visit was 618 ng/mL. TSH 1.33. Brain MRI at that time did not reveal a pituitary mass, though pituitary protocol was not performed. Prolactin repeated on our initial visit had increased to 1352 ng/mL. Pituitary MRI was without evidence of pituitary mass. Despite discussing the importance of estrogen replacement, the patient was not interested in OCP therapy due to prior intolerance. Clinical Lesson(s): Hyperprolactinemia can be seen in patients on hemodialysis as a result of increased secretion in the uremic state and decreased clearance. Dialysis does not significantly improve the prolactin level. A recent study revealed a median prolactin of 65.2 ng/mL in dialysis patients. Our case emphasizes that the degree of hyperprolactinemia as a result of ESRD and medications can vary widely. It remains important to continue to consider the diagnosis of pituitary pathology in patients with a prolactin level that is higher than expected. However, if imaging is unrevealing, as in our patient, hyperprolactinemia may be attributed to medications and pathological disease states. Elevated serum prolactin has been shown to increase cardiovascular and all-cause mortality in a level-dependent effect. Hyperprolactinemia has also been associated with insulin resistance and worsened diabetes control. As we continue to learn more regarding the negative side effects of prolactin, it may become increasingly important to monitor and reduce prolactin levels in our patients, especially those on dialysis already with an elevated risk of cardiovascular disease.