A 46-year-old man comes to the office due to fatigue, loss of libido, and erectile dysfunction for the past 4 months. His other medical problems include type 2 diabetes, hypertension, hyperlipidemia, seizure disorder, hepatitis C, hypothyroidism, and chronic kidney disease. The patient's current medications include long-acting insulin, lisinopril, amlodipine, furosemide, aspirin, levothyroxine, calcitriol, calcium carbonate, and phenytoin. He has a remote history of cocaine and heroin use 20 years ago and has smoked a pack of cigarettes daily for the past 25 years. He does not drink alcohol.
Blood pressure is 155/95 mm Hg and pulse is 80/min. BMI is 35 kg/m². Examination shows hepatomegaly and 1+ pitting edema to the mid-shin bilaterally. Secondary sexual characteristics and testicular examination are unremarkable. Visual fields are normal on confrontation.
Laboratory results are as follows:
Which of the following is the most likely cause of this patient's hyperprolactinemia?

Question

A 46-year-old man comes to the office due to fatigue, loss of libido, and erectile dysfunction for the past 4 months. His other medical problems include type 2 diabetes, hypertension, hyperlipidemia, seizure disorder, hepatitis C, hypothyroidism, and chronic kidney disease. The patient's current medications include long-acting insulin, lisinopril, amlodipine, furosemide, aspirin, levothyroxine, calcitriol, calcium carbonate, and phenytoin. He has a remote history of cocaine and heroin use 20 years ago and has smoked a pack of cigarettes daily for the past 25 years. He does not drink alcohol.
Blood pressure is 155/95 mm Hg and pulse is 80/min. BMI is 35 kg/m². Examination shows hepatomegaly and 1+ pitting edema to the mid-shin bilaterally. Secondary sexual characteristics and testicular examination are unremarkable. Visual fields are normal on confrontation.
Laboratory results are as follows:

Which of the following is the most likely cause of this patient's hyperprolactinemia?

Quizplus · Accepted Answer

11ec193a_97a4_56cf_853d_d5c24fb06396_MD0002_00 This patient has hyperprolactinemia, most likely due to chronic kidney disease (CKD). Hyperprolactinemia is common in CKD due to a 3-fold increase in prolactin release (as a result of an altered inhibitory effect of dopamine) and a 30% decrease in prolactin clearance. Prolactin levels are usually modestly elevated (<100 ng/mL). Men may experience decreased libido, erectile dysfunction, infertility, gynecomastia, or (rarely) galactorrhea. Premenopausal women often have galactorrhea and menstrual irregularities, whereas postmenopausal women are usually asymptomatic. Prolactin levels in patients with CKD do not respond to hemodialysis but can be normalized with dopamine agonists (eg, bromocriptine, cabergoline). However, sexual dysfunction often persists due to additional contributing factors (eg, neuropathy, vascular disease, medications). Low serum testosterone levels also are common in CKD, but testosterone therapy does not improve symptoms in most patients. (Choice B) Men with cirrhosis can develop sexual dysfunction with testicular atrophy and an increased estrogen-to-androgen ratio. This patient does not have prominent estrogenic features (eg, gynecomastia, spider angiomata), and chronic liver disease is not a common cause of hyperprolactinemia. (Choice C) Prolactin levels increase in untreated primary hypothyroidism due to the stimulatory effect of thyrotropin-releasing hormone on prolactin release. This patient's normal TSH indicates adequate treatment of hypothyroidism. (Choice D) The most common cause of medication-induced hyperprolactinemia is antipsychotics (eg, haloperidol, risperidone) due to their effects on dopamine suppression of prolactin release. Antidepressants (eg, amitriptyline, sertraline), prokinetic drugs (eg, metoclopramide), and opiates (eg, morphine) are also commonly implicated. This patient's medications (eg, phenytoin) only rarely cause hyperprolactinemia. (Choice E) Serum prolactin is transiently elevated after a generalized seizure and can sometimes be used to differentiate between true seizures and pseudoseizures. However, prolactin is not usually elevated in chronic seizure disorders controlled with medications, as in this patient. Educational objective: Hyperprolactinemia is common in chronic renal failure due to increased release and decreased clearance of prolactin. Prolactin levels can be normalized with dopamine agonists, but sexual dysfunction often persists due to additional contributing factors. __________ References: Hyperprolactinemia in end-stage renal disease and effects of frequent hemodialysis. (http://www.ncbi.nlm.nih.gov/pubmed/27774730)

A 46-Year-Old Man Comes to the Office Due to Fatigue