pituitary drugs

six anterior pituitary hormones

-GH

-PRL

-TSH

-ACTH

-FSH

-LH

two posterior pituitary hormones

-vasopressin

-oxytocin

GHRH

-released by hypothalamus

-stimulates GH release

somatostatin

-released by hypothalamus

-inhibits GH release

GH (somatropin) pharmacological effects

-decreased body fat and increased muscle/bone mass

-stimulates protein synthesis

increased lipolysis and blood glucose synthesis/release

s/e of GH abuse

-hyperglycemia

hypothalamic dwarfism and treatment

-decreased GHRH

-GH analog (somatropin)

pituitary dwarfism and treatment

-decreased GH

-GH analog (somatropin)

laron dwarfism cause and treatment

-defective GH receptors in liver = inadequate IGF-1 production

-IGF-1 analog (mecasermin)

laron dwarfism plasma hormone levels

-GH are normal or increased

-IGF-1 are decreased

somatropin clincal uses

-replacement therapy for GH deficiency in children

-AIDs induced wasting syndrome

somatropin ADEs

-intracranial hypertension (rare)

-arthralgia, myalgia

-peripheral edema

-hyperglycemia

somatropin caution

-don’t administer to pts with active/history of malignant tumors

IGF-1 analog

-mecasermin

mecasermin MOA

-stimulates IGF-1 receptors and improves growth and metabolic effects

mecasermin pharmacological effects

-increased muscle mass and decreased body fat

-increases bone growth/density

-increases lipolysis

mecasermin clinical uses

-laron dwarfism

mecasermin ADEs

-hypoglycemia

-intracranial hypertension (rare)

mecasermin caution

-don’t administer to pts with active/history of malignant tumors

gigantism

-excessive GH secretion before puberty

acromegaly

-excessive GH secretion after puberty

3 treatment options for GH excess

-trans-sphenoidal surgical resection

-radiation therapy

-pharmacological (inhibit secretion or block action)

somatostatin analogs (SST) “moa”

-inhibit GH secretion

SST analogs

-octreotide

-lanreotide

-pasireotide

dopamine agonists “moa”

-inhibit GH secretion

dopamine agonists

-bromocriptine

-cabergoline

GH receptor antagonist “moa”

-block GH action

GH receptor antagonist

-pegvisomant

prolactin (PRL)

-primary hormone responsible for lactation

-major stimulus = suckling

-under tonic inhibitory control via dopamine

-not used clinically

high PRL levels in men

-decreased sperm production

high PRL levels in women

-inhibition of ovulation

-irregular/missed periods

treatment options for hyperprolactinemia

-trans-sphenoidal surgical resection

-radiation therapy

-pharmacological = dopamine agonists

dopamine agonists moa

-inhibits prolactin release via stimulating dopamine receptors

dopamine agonists clinical uses

-hyperprolactinemia

-acromegaly

dopamine agonist ADEs

-nausea

-headaches

-orthostatic hypotension

vasopressin (ADH)

-released in response to increased plasma osmolality or decreased blood volume

diabetes insipidus

-inadequate ADH secretion

desmopressin moa

-stimulates V2 receptors in kidneys = water retention

-long acting vasopressin analog

desmopressin clinical uses

-DI

-nocturnal enuresis

-bleeding disorders

desmopressin ADEs

-GI disturbances

-hyponatremia

-allergic reactions

SIADH

-persistent stimulation of V1 and V2 receptors

effects of SIADH

-hypertension and excessive water retention

-dilution of extracellular Na (hyponatremia)

-convulsions, coma, death

SIADH treatment

-vasopressin receptor antagonists

vasopressin receptor antagonists

-conivaptan (V1 and V2)

-tolvaptan (selective of V2)

vasopressin receptor antagonist ADEs

-dry mouth

-increased thirst

-excessive urination

-hypernatremia

oxytocin

-released by sensory stimulation from dilation of the cervix during labor/breast suckling

oxytocin pharmacological effects

-uterine smooth muscle = uterine contractions to facilitate labor

-myoepithelial cells in breast for milk letdown

oxytocin clincal uses

-initiation and augmentation of labor

-promote milk letdown

-reduce or prevent post-partum hemorrhage (PPH)

oxytocin ADEs

-uterine hyperstimulation

-hypotension

-hyponatremia/water retention