Hyperprolactinemia

00:01 Physiologically, prolactin induces and regulates lactation.

00:05 Hence, elevated levels of prolactin cause galactorrhea or abnormal lactation.

00:11 Women are more likely to develop galactorrhea than men.

00:15 Hyperprolactinemia also causes hypogonadotropic hypogonadism because of its negative feedback effect on gonadotropin-releasing hormone in the hypothalamus which in turn decreases the levels of LH and FSH.

00:29 Both men and women can present with hypogonadism.

00:32 Unlike other pituitary tumors, medication rather than surgery is first-line therapy for prolactinomas.

00:39 Even patients with severe mass effects such as vision loss are treated with medical therapy initially.

00:45 Rarely, very large tumors or more invasive prolactinomas do not shrink with medical therapy and continue to grow.

00:53 Surgery should be considered followed by radiotherapy if growth occurs or continues.

01:00 After being debulked, the prolactinoma may respond better to medical therapy.

01:05 This table reviews the different causes of hyperprolactinemia.

01:09 Starting with physiologic changes, the most important one is pregnancy, and lactation, as well as nipple stimulation.

01:16 Important medications to consider include antipsychotic agents, metoclopramide, cimetidine, verapamil, methyldopa, opiates, and cocaine.

01:27 Other causes of hyperprolactinemia include prolactinomas, pituitary tumors, hypothyroidism, cirrhosis, and chronic kidney disease.

01:36 Let's take a look at some of these in more detail.

01:39 The most common cause of elevated levels of prolactin are obviously pregnancy, and in the postpartum period, to facilitate lactation.

01:48 Physiologic stress, coitus, and exercise can increase prolactin levels up to 14 nanograms per ml.

01:55 Normal ranges numerical include two to 29 nanograms per ml in non-pregnant women, and two to 18 nanograms per ml in men.

02:06 Nipple piercing can increase prolactin levels above 200 nanograms per ml.

02:13 Antipsychotic agents cause hyperprolactinemia due to their antidopaminergic effect that interrupts the inhibition of prolactin by dopamine.

02:22 Specific agents such as risperidone and metoclopramide may raise the prolactin level above 200 nanograms per ml.

02:29 Evaluate for pituitary hypersecretion when a patient is taking a medication known to raise the prolactin level.

02:36 When the prolactin level is only mildly elevated, less than 50 nanograms per ml, it may be reasonable to assume that hyperprolactinemia is a medication side effect.

02:46 When significantly elevated, above 100 nanograms per ml, either the medication needs to be withheld or further assess a pituitary MRI obtained to evaluate for a prolactinoma.

03:00 Caution is warranted when discontinuation of an antipsychotic agent is being considered, and consultation with the psychiatrist who actually prescribed it is recommended prior to acute discontinuation.

03:12 Another cause of hypoprolactinemia is primary hyperthyroidism.

03:17 Hypothyroidism can cause diffuse swelling of the pituitary gland that may resemble enlargement due to a pituitary adenoma on imaging.

03:26 A patient with primary hypothyroidism and hyperprolactinemia should be treated with thyroid hormone replacement with the retesting of the prolactin level once the TSH has normalized.

03:37 Further evaluation is indicated if the hyperprolactinemia does not correct when hyporthyroidism is treated.

03:45 Clinical features and diagnosis of hyperprolactinemia.

03:48 Symptoms in men are insidious and may go unrecognized for years.

03:53 Both men and women with hyperprolactinemia are likely to be infertile and are at risk for osteoporosis.

04:01 Postmenopausal women are already hypogonadal because of ovarian failure.

04:06 Therefore, hyperprolactinemia may have minimal clinical implications in this group of patients.

04:12 The cause of postmenopausal hyperprolactinemia still requires diagnosis because it may be due to a pituitary tumor that can have effects within the brain.