Hyperprolactinemia & prolactinomas

Kane

When is prolacting released from?

Lactotroph in anterior pituitary

What is prolactin release regulated by>

inhibitory signals (dopamine) from hypothalamus

What is the function of prolactin?

induces growth and differentiation of cells in mammary gland and essential for lactation

What does elevated prolactin levels inhibit?

GnRH & sex hormone production

What is Hyperprolactinemia characterized by?

Prolactin level >30 ng/mL

norm: 15-25 ng/mL

>200 ng/mL usually from prolactin-secreting pituitary tumor

What are some causes for modest Hyperprolactinemia?

pregnancy (early)/lactation

stress (discomfort, exercise, low BS)

hypothyroidism

Kidney failure

Liver failure

“Stalk” effect

Medications

What are some causes of severe hyperprolactinemia?

Macro/microprolactinoma

“hook” effect

What are prolactinomas and how are they classified?

Benign prolactin-secreting pituitary tumor - most common found on 12% of autopsies

classified on size: micro or macro

* microadenomoa

How are prolactinomas diagnoses and what else is measured?

imagining

Measure other anterior pituitary hormones for deficiencies

what is typical of D-I hyperprolactinemia?

prolactin

What is the treatment for D-I hyperprolactinemia?

D/C offending agent & initiate alternative

How do women with a hyperprolactinemia present?

estrogen deficiency

* irregular periods or amenorrhea
* infertility
* galactorrhea
* reduction in sex drive

vision loss/heachache (prolactinoma)

OP if long-term

How do men present with hyperprolactinemia?

Loss of sex hormone production

* loss of libido
* ED
* loss of body hair
* infertility

Vision loss/headache (prolactinoma)

OP if long-term

How is hyperprolactinemia diagnosed?

S/S of sex hormone deficiency

Elevated Prolactin (>30)

Preform pituitary hormone evaluation

Find cause

Imaging studies (MRI)

What are goals of therapy for hyperprolactinemia?

alleviate symptoms

normalize gonadotropin hormone

promote tumor shrinkage & correction of visual defects

normalize prolactin level

What are the drug therapies for prolactinomas?

Bromocriptine

Cabergoline

D2 receptor antagonist

What are non-pharamcologic for prolactinomas?

Surgery (transsphenodial)

RT (Stereotactic radiation & external beam radiation)

What is the MOA of Cabergoline?

D2 receptor inhibitor

Better GI tolerance

MD: 1 mg twice yearly, Initiate @ .25 mg twice weekly increase by 0.5 mg every 4 weeks

What is the MOA of Bromocriptine?

D2 receptor antagonist

Initiate 1.25 -2.5 mg daily W/ FOOD, increase q2-7 days MD 15mg

many pts non responsive to cabergoline

preferred in pregnancy

What are AE of Bromocriptine or Cabergoline?

Nausea (take w/ food)/V, diarrhea, headache

Orhtostatic hypotension, dizziness

Worsening of psychosis

Heart valve disorders (Parkinson’s doses)

What are CI for Bromocriptine & cabergoline?

Nursing mom’s

uncontrolled HTN, orthostatsis, heart valve d/o

What are drug interactions for dopamine antagonists?

Dopamine antagonist

3A4 metabolism

What needs to be monitored on d2 antagonists?

Normalization of prolactin (w/ NO AD → CONT)

resolution of symptoms (few months for gonad function return)

Shrinkage of tumore & MRI in 6-12 months

What is the duration of D2 antagonists?

Recieve @ least 2 years & serum prolactin & absence of visible tumor

What do you do for a pregnancy in a prolactinoma?

D/C treatment

monitor for tumor growth & may restart if needed w/ bromocriptine

After pregnancy what is the treatment for hyperprolactinoma?

Treatment withheld during breastfeed

if visual impairment restart → stop breastfeeding

measure prolactin 3 months after delivery or after cessation of breast feeding (norm 6-12 month)