Endocrine System
Hypothalamus
Involved in regulating many functions, including sleep-wake cycles, body
temperature, and appetite. It can also regulate the function of other endocrine
glands.
Pituitary
Hormones it produces affect growth and reproduction. They can also control the
function of other endocrine glands.
Anterior Pituitary hormones:
Growth hormone, Adrenocorticotropic hormone (ACTH), Thyroid-stimulating
hormone (TSH), FSH, LH, Prolactin, Melanocyte-stimulating hormone (MSH)
What does FSH do?
Development of the eggs in the ovaries and estrogen production, stimulates
sperm prod.
What does LH do?
progesterone, ovulation, egg release, testosterone production
Pineal
Sleep-wake cycles.
Thyroid is for
Metabolism
Thyroid hormones:
T3, T4, calcitonin
Parathyroid
Maintaining control of calcium levels in your bones and blood.
Thymus
Active until puberty and produces hormones important for the development of T
cells (wbc).
Adrenal
Regulating functions such as blood pressure, heart rate, and stress response.
Adrenal Cortex
outermost to innermost layers, they are
(1) the zona glomerulosa, (2) the zona fasciculata, and (3) the zona reticularis.
The hormones synthesized and secreted are
steroids and consist of
mineralocorticoids, glucocorticoids, and androgens or estrogens.
Mineralocorticoids:
maintain adequate extracellular volume
Produced by
zone glomerulosa
Most abundant:
Aldosterone
Aldosterone functions:
at the renal collecting tubule, promotes reabsorption of sodium and excretion of
potassium by kidney (salt/water balance)
Secretion of Aldosterone is regulated by:
levels of potassium, the renin-angiotensin mechanism, and ACTH.
Glucocorticoids are produced by the:
zona reticularis and zona fasciculata of the adrenal cortex
Most abundant of glucocorticoids?
Cortisol (stress hormone)
Glucocorticoid functions include
control of carbohydrate, lipid, and fat metabolism; regulation of antiinflammatory
and immune responses; and control of emotional states
Androgens:
steroid; masculinization in men; adrenal
Estrogen is supplied by the
adrenal glands and ovaries
Metabolic rate falls -> hypothalamus stimulates pituitary gland -> pituitary
secretes TSH -> stimulates thyroid gland -> thyroid secretes hormones that affect
production and use of energy
Thyroid hormone is also called
thyroxine, tetraiodothyronine, or T4.
Triiodothyronine is referred to as
T3
What does T4 and T3 do?
increase the body's metabolic rate.
Calcitonin, or thyrocalcitonin, plays a role in
regulating the serum calcium level. when serum calcium levels are high its
secreted, limiting the shift of calcium from the bones into the blood.
What does the parathyroid secrete?
PTH, also called parathormone
Which plays a vital role in
regulating the serum calcium level.
(When the serum calcium level falls, PTH is secreted. PTH increases the
absorption of calcium from the intestines, transfers calcium from the bones to the
blood, and signals the kidneys to conserve calcium.)
AGE RELATED CHANGES (4)
 Body doesn’t respond to ADH as much/well. Less able to compensate
for fluid loss or inad. Fluid intake. ^ risk of dehydration
 Decline in GH and IGF1, resulting in less protein being made, less lean
body and bone mass, and reduced immune function.
 Decline in cortisol
 Decline in aldosterone and renin (decreases sodium conservation)
Functional assessment includes:
sleep disturbances or changes in appetite. usual diet and how symptoms are
affecting usual activities and self-esteem.
spasm of the facial muscle when the face is tapped over the facial nerve.
Chvostek sign
carpopedal spasm that occurs when a BP cuff is inflated above the patient's
systolic BP and left in place for 2 to 3 minutes
Trousseau sign
Chvostek sign and Trousseau sign are both indicative of
hypocalcemia
radioimmunoassay and the enzyme-linked immunosorbent assay (ELISA) are tests
that measure
levels of hormones in the blood.
most useful tests of thyroid function are measurements of
serum TSH and free T4
This test shows if thyroid hormone abnormalities are caused by thyroid gland or
by hypothalamus or the pituitary
TRH [thyroid releasing hormone] stimulation test (measures TSH)
RAI uptake test
RAI isotopes concentrate in the thyroid, measures how much
48 Pituitary and Adrenal Disorders
Dysfunction of the pituitary gland can result from
a problem in the gland itself or from a problem in the hypothalamus
Hyperpituitarism is caused by
excess production of one or more of the anterior pituitary hormones
Which are:
Growth hormone (GH), prolactin, follicle-stimulating hormone (FSH), luteinizing
hormone (LH), and adrenocorticotrophic hormone (ACTH)
Overproduction of GH can lead to
gigantism or acromegaly.
Overproduction of prolactin causes
hyperprolactinemia.
adenoma is a
benign tumor composed of epithelial tissue. vary in size and invasiveness.
Adenomas larger than 10 mm are called; smaller than 10mm
macroadenomas; microadenomas
most common factor in hyperpituitarism is the presence of
a pituitary adenoma
Adenomas tend to occur most commonly in
young women in their teens through early 30s
Excess growth hormone can cause:
Hyperglycemia, dm, atherosclerosis, cod,
prolactinemia, characterized by
abnormal lactation (galactorrhea), amenorrhea, decreased vaginal lubrication,
impotence and decreased libido in men, depression, anxiety, and visual loss.
Gigantism occurs during
early childhood or puberty, while the long bones of the body are still growing
And
Before the growth plates close, long shaft of the bone may grow to great lengths
when there’s excess GH. The growth in these bones is usually proportional. Often
die in early adulthood.
although rare, is more common than gigantism. excess GH production occurs
after epiphyseal closure
Acromegaly
closed epiphyses prevent longitudinal growth of the bones; instead, bones
increase in thickness and width
Most patients with acromegaly are found to have
pituitary macroadenomas that secrete excess GH.
Symptoms usually appear
in fourth or fifth decade of life
Acromegaly also affects the
cardiovascular, digestive, nervous, and genitourinary systems
In hyperpituitarism this may be the first symptoms of a problem
Visual deficits (from pressure on optic nerves) and headaches
Physical features of the disease include
enlargement of the hands, feet, and paranasal and frontal sinuses and deformities
of the spine and mandible.
In addition, soft tissues may become enlarged, especially the
tongue, skin, liver, and spleen. This may in turn lead to speech impediments,
coarse or distorted facial features, abdominal distention, and sleep apnea.
People with acromegaly may also report excessive
perspiration (diaphoresis), oily skin, peripheral neuropathies, degeneration of the
joints, and proximal muscle weakness.
The effects of excess GH impede the activity of
insulin, causing patients to have symptoms of DM.
In addition to the features just described, patients with gigantism and acromegaly
initially have
increased strength, progressing rapidly to complaints of weakness and fatigue.
The skilled examiner may also detect
organomegaly (i.e., enlargement of internal organs), hypertension, dysphagia, and
a deep voice because of hypertrophy of the larynx.
Those patients who also have elevated levels of prolactin may have
galactorrhea (in women) or hypogonadism (in men).
Radiographic films of pt with hyperpituitarism, the skull may show
a large sella turcica and increased bone density.
In patients with possible hyperpituitarism what is measured
levels of anterior pituitary hormones
It is normal for LH and FSH to be slightly elevated in postmenopausal women.
Elevated levels of GH and insulin growth factor-1 (IGF-1) suggest
acromegaly.
The GH suppression test is the most definitive test for
acromegaly. Although the GH concentration normally falls in response to glucose,
it is unchanged in the patient with acromegaly.
Dexamethasone suppression tests are used to rule out
problems related to dysfunction of the adrenal glands
Treatment of choice for patients w pituitary tumors is
hypophysectomy; which is
the surgical removal of the adenoma or of the pituitary itself
transsphenoidal hypophysectomy is a microsurgical procedure
under general anesthesia with the patient in the semi-Fowler position. An incision
is made at the inner upper lip
If the entire pituitary is removed, the patient will
need lifelong replacement of glucocorticoids, thyroid hormone, sex hormones.
is the most commonly prescribed drug for patients with acromegaly
Octreotide (Sandostatin, Sandostatin Depot
Sandostatin
a short-acting preparation, is given every 8 hours by subcutaneous injection.
Sandostatin Depot is long acting and is given by intramuscular (IM) injection every
4 weeks.
Common side effects of octreotide acetate are headache, changes in cardiac
conduction, nausea, vomiting, diarrhea, abdominal pain, gallstones, reduction in
insulin release, hyper or hypoglycemia, and transient pain at the injection site.
Because this drug also suppresses insulin secretion, the patient's blood glucose
must be monitored. Blood pressure (BP) and weight are monitored to detect fluid
retention
Dopamine receptor agonists such as cabergoline (Dostinex) suppress
the secretion of GH.
most often used after radiotherapy and pituitary surgery
Pegvisomant (Somavert)
Bromocriptine (Parlodel) was once the primary drug but it has been largely
replaced by the newer options that have fewer side effects. Some of the most
common side effects of bromocriptine are headache, dizziness, drowsiness,
confusion, nausea, vomiting, dry mouth, and urticaria.
Surgery for hyperpituitarism?
hypophysectomy; removes pituitary to treat tumor
What should be assessed after hypophysectomy?
Neuro, LOC, decreased/asymmetric muscle strength. Changes may indicate
edema or intracranial bleeding.
Possible complications of hypophysectomy?
Diabetes insipidus, SIADH (syndrome of inappropriate antidiuretic hormone), csf
leak, meningitis ; Increased ICP (visual disturbances)
Signs of diabetes insipidus and siadh?
I and O; specific gravity
What is diabetes insipidus?
A disorder of salt and water metabolism marked by intense thirst and heavy
urination (diluted)/ pituitary hormone ADH/vasopressin is impaired decreased
What is SIADH?
A condition in which high levels of a hormone (adh/vasopressin) cause the body
to retain water. And dilutes sodium.
What is specific gravity normal level?
1.01-1.03 (below this is more diluted)
indications of meningitis
elevated white blood cell (WBC) count, sudden rise in temperature, headache, or
nuchal rigidity, severe head or neck pain when touching the chin to the chest.
Hypophysectomy teaching:
• If the anterior pituitary is removed, you will need hormone replacements for the
rest of your life.
• For 3 months (or as advised by your physician), avoid any activities that cause
straining, heavy lifting, and bending from the waist.
• It is important to prevent constipation because straining increases intracranial
pressure.
• Numbness of the incision area and decreased sense of smell are temporary.
dwarfism may result from
inadequate secretion of GH occurs during preadolescence; damage to anterior
pituitary
Dwarfism
attainment of a maximum height that is 40% below normal
growth is completed and a pathologic process impairs the function of the pituitary
panhypopituitarism
with deficiency of thyroid-stimulating hormone (TSH) you need
thyroid replacement; levothyroxine (Synthroid) or liothyronine (Cytomel), usually
for the rest of the person's life. Gonadotropin deficiency requires lifelong therapy.
Symptoms of diabetes insipidus
fluid volume defecit, large amt.s of diluted pee, extreme fatigue and weakness,
thirst, wt. loss, too little adh/vasopressin
Symptoms of SIADH
Increased adh/vasopressin, increased bp, fluid retention, low sodium, increased
icp, increased HR, weakness, muscle cramps or twitching, anorexia, nausea,
diarrhea, irritability, headache, wt gain, change in LOC, concentrated urine
Acutely ill siadh pt’s (with neurologic symptoms and sodium of 120) treated with:
hypertonic saline solution
 SIADH:
 Maintain a daily fluid intake of 800 to 1000 mL/day or as advised by your
physician.
 Ice chips and sugarless chewing gums may help you to manage thirst.
 Weigh daily and notify the physician if you gain 2 lb or more in 1 day.
Adverse affects of Demeclocycline for siadh:
increased urea and waste in blood, nephrotoxicity (kidney)
Lithium toxicity symptoms:
tremor, increased reflexes, trouble walking, kidney problems, and an altered level
of consciousness, diarrhea, fatigue
DISORDERS OF ADRENAL GLANDS:
Adrenal hypofunction or primary adrenal insufficiency
addisons disease
Addison is a result of:
a destructive disease affecting the adrenal glands; causes decreased cortisol and
aldosterone.
The most common cause of Addison disease is
idiopathic atrophy (an autoimmune disease in which adrenal tissue is destroyed
by antibodies formed by the patient's own immune system.)
Secondary adrenal insufficiency is a result of
dysfunction of the hypothalamus or pituitary (decreased corticotropin, ACTH),
which leads to decreased androgen and cortisol production. Can be from tumor.
Aldosterone may or may not be affected in secondary
Androgens:
play a role in male traits and reproductive activity. Present in both males and
females. Secreted in adrenal gland
adrenal gland secretes
steroid hormones such as cortisol and aldosterone; androgen, estrogen
possible complications or symptoms of Addison disease:
hypoglycemia, hyperkalemia, metabolic acidosis, hypovolemia, hyponatremia (not
enough aldosterone to regulate water retention, so water is excreted fast. Not
enough cortisol to regulate glucose so hypoglycemia), weakness, lethargy,
abdominal pain, Skin hyperpigmentation, hair loss
Acute Adrenal Crisis (Addisonian Crisis) can be caused by
emergency. Stress, trauma, surgery, infection abrupt stopping of steroids
If left untreated (adrenal crisis)
fluid and electrolyte imbalances can lead to circulatory collapse or dysrhythmias
Emergency medical care for adrenal crisis:
cortisol levels, IV saline 5% dextrose, hydrocortisone
Diagnosis of adrenal crisis:
24-hour urine (reflects steroid secretion over period, most accurate measurement
of steroid secretion, varies with the diurnal rhythm. (Glucocorticoids normally peak in the
early morning and are at their lowest level in the afternoon); acth levels, cortisol levels
treatment of patients with Addison disease:
replacement therapy with glucocorticoids and mineralocorticoids. Hydrocortisone
is commonly used because it contains both. Check circulation.
Addisonian crisis is treated with
iv fluids, hydrocortisone, electrolytes, dextrose to restore bp (from hypotension)
Adrenal Hypersecretion (Cushing Syndrome)
Hypersecretion of the adrenal cortex may result in the production of excess
amounts of corticosteroids, particularly glucocorticoid. The condition that results
from excessive cortisol. Prolonged corticosteroid use. Some caused by tumors.
Symptoms of cushings:
Truncal obesity (excess adipose in body trunk), protein wasting (slender
extremities and very thin and friable skin), Facial fullness, often called a moon
face, Purple striae on the abdomen, breasts, buttocks, or thighs, Osteoporosis (a
significant finding in premenopausal women), Hypokalemia, hypertension
Diagnositcs for cushings:
24-hour urine collection for free cortisol. Or ct/mri to look for tumor
Treatment for cushings:
potassium-sparing diuretic spironolactone, Lysodren for tumors (pit. Adenoma)
Drugs that suppress adrenal function can lead to acute adrenal crisis
Patients with Cushing syndrome should be cautioned that long-term use of:
celery, juniper, licorice, and parsley, can cause hypokalemia.
Pt. problems r/t cushings
Potential for infection related to high serum cortisol levels, Potential for injury
(fracture) related to osteoporosis, Potential for disrupted skin integrity related to
changes in skin and connective tissue and edema
Exposure to people with infections should be avoided because of the patient's decreased
resistance to infection. Minor symptoms, such as a low-grade fever (99.5°F or higher), sore
throat, or aches, can indicate the onset of a potentially serious infection. Any symptoms
indicative of a cold or other problem should be brought to the attention of the physician. Avoid
people with infections because you have increased risk of infections; report any temperature
elevation to your physician. Mood swings and changes in appearance are usually corrected with
treatment. Avoid activities that could result in trauma because you have increased risk of
bleeding and fractures.
symptoms of impending shock after adrenalectomy:
hypotension, a weak or thready pulse, decreased urinary output, and changes in
level of consciousness.
Pulse and BP may be unstable
for 24 to 48 hours after surgery
may be needed to maintain BP in the immediate postoperative period
and vasopressors
problem specific to the adrenalectomy patient is potential for injury related to
addisonian crisis as a result of the sudden decrease in adrenal hormone secretion.
symptoms of acute adrenal insufficiency:
vomiting, weakness, hypotension, joint pain, pruritus, and emotional
disturbances.
Early symptoms of Addison disease may include
anorexia, nausea, vomiting, diarrhea, and weight loss, resulting in impaired
nutrition.
Patients with Addison disease are advised not to restrict
salt intake.
Patients with Cushing syndrome may experience retention of
sodium and water
Diet therapy for Cushing syndrome may include
decreased caloric and sodium intake and increased potassium intake.
Reducing sodium intake can decrease edema and related weight gain with
Cushing syndrome.
Patients with diabetes insipidus (DI) usually experience:
excessive thirst or urination
so they (DI) must drink liquids almost continuously to avoid
dehydration and hypovolemic shock.
pheochromocytoma is a
tumor, usually benign, of the adrenal medulla that causes secretion of excessive
catecholamines (i.e., epinephrine, norepinephrine)
Patients with a pheochromocytoma exhibit episodes of
severe hypertension, hypermetabolism, and hyperglycemia.
The classic clinical findings are
hypertension with a diastolic pressure of 115 mm Hg or higher; severe, pounding
headache; and diaphoresis (profuse sweating). flank pain
Episodes may be triggered by
emotional distress, exercise, manipulation of the tumor, postural changes, trauma
special postoperative problems in the patient with pheochromocytoma include
greater risk for fluctuations in blood pressure and hypoglycemia
Hyperpituitarism, caused by
excess anterior pituitary hormones,
leads to
gigantism or acromegaly.
Hyperpituitarism is treated with
drugs or surgery to remove the tumor or the entire pituitary (hypophysectomy)
Panhypopituitarism is a deficiency of
all anterior pituitary hormones
and is treated with
replacement hormones.
DI, caused by
deficit in ADH
results in
massive diuresis
and is treated with
vasopressin.
SIADH, caused by
excess ADH,
results in
fluid retention and is treated with
diuretics and demeclocycline.
Primary adrenal insufficiency (Addison disease) causes
hypoglycemia, hyperkalemia, hyponatremia, and hypovolemia and requires
lifelong replacement of
glucocorticoids and mineralocorticoids.
Acute adrenal crisis is a life-threatening emergency caused by a
sudden marked decrease in adrenal hormones that can lead to circulatory
collapse and death.
Cushing syndrome results from
hypersecretion of cortisol, a glucocorticoid, or from prolonged administration of
corticosteroids.
Cushing syndrome is characterized by
polycythemia, hypokalemia, hyperglycemia, leukocytosis, and glycosuria.
Nursing care for the patient with Cushing syndrome is concerned with
potential for infection, anxiety, potential for disrupted skin integrity
A pheochromocytoma is an
adrenal tumor that increases secretion of
catecholamines, causing
hypertension, hypermetabolism, and hyperglycemia.
THYROID AND PARATHYROID
Hyperthyroidism, or thyrotoxicosis, is characterized by
abnormally increased synthesis and secretion of thyroid hormones.
The most common types of hyperthyroidism are
Graves disease and multinodular goiter.
Antibodies activate TSH, which stimulates thyroid enlarge & hormone secretion.
graves disease
periods of remission and exacerbation. Some patients with Graves disease
eventually develop
hypothyroidism.
Hyperthyroidism symptoms
weight loss, anxiety; hair loss, fatigue, sleep disturbance, irritable, poor tolerance
of heat, sweating, warm/velvety skin, tremors hand, eyes bulge/exophthalmos
Excess thyroid hormones stimulate the heart, causing tachycardia, increased
systolic BP, and sometimes atrial fibrillation. (dermopathy) itching and thickening
on shins
hyrotoxicosis, referred to as thyrotoxic crisis or thyroid storm, is a medical
emergency caused by:
Excessive stimulation from elevated thyroid levels can produce dangerous
tachycardia and hyperthermia. A risk of heart failure.restless, agitated, risk coma
how do you diagnose graves disease?
test tsh and t4. Tsh decreased; t4 elevated. RAI uptake test
Three methods are used to treat hyperthyroidism:
(1) drug therapy, (2) radiation therapy, and (3) surgery.
may be given to relieve cardiovascular symptoms from hyperthyroidism:
propranolol (Inderal)
what drugs can treat hyperthyroidism?
Thionamides and iodides are antithyroid drugs
Thionamides.
Propylthiouracil (PTU) and methimazole (Tapazole).
It can take up to _ weeks before the effects of thionamides are noticeable.
8; The drugs may be given for months or years.
The goal is to
induce a remission that will allow the drugs to be discontinued.
What tests are important while on theonamides/antithryoid meds
Thyroid function tests must be done regularly to prevent hypothyroidism.
Rare but serious adverse effects of thionamides are
hepatitis and agranulocytosis.
Agranulocytosis is a condition in which the production of
neutrophils is suppressed.
Iodides.
Iodides are useful because iodine inhibits the synthesis of
thyroid hormones.; The iodides may also be used to treat thyrotoxicosis/thyroid
storm.
Saturated solution of potassium iodide (SSKI) can be given to people who
have been exposed to radiation to prevent damage to the thyroid gland.
Iodine solutions can cause
discoloration of the teeth and gastric upset. effects minimized if the iodine
solution is diluted with milk, fruit juice through a straw.
Signs of iodine toxicity include
swelling and irritation of the mucous membranes and increased salivation.
RAI (131I) used to treat
hyperthyroidism. accumulates in thyroid gland, where it destroys thyroid tissue.
Contraindications of RAI:
pregnancy. May cause thyroiditis and parotiditis (dry mouth). Hypothyroidism
may develop years after treatment.
With surgical removed of thyroid, thyroid hormones can get into bloodstream and
cause a thyroid storm.
Patient problems of hyperthyroidism:
Decreased cardiac output related to cardiac dysrhythmias or heart failure caused
by excessive thyroid hormone stimulation
sleep distrubances
heat intolerance, hyperthermia
inadequate nutrition (need more calories)
eye injury exophthalmos (eye bulging) (limit salt, lubricate eyes, tape shut, ^hob
diarrhea from excessive TSH
Lack of iodine is associated with the development of a
goiter (enlargement of the thyroid gland) in adults, cretinism in infants. (add salt)
Parathyroid hormone (PTH), secreted by the parathyroid gland, and
thyrocalcitonin, secreted by the thyroid gland, maintain
serum calcium levels.
For eye symptoms, medications:
Methylcellulose eye drops and diuretics may be ordered to decrease
inflammation and swelling. And maybe prednisone for couple weeks
After thyroid surgery
support head when getting up.
Rare but serious complications of thyroidectomy are
airway obstruction, recurrent laryngeal nerve damage (inflammation will cause
airway obstruction), low calcium if parathyroid is damaged. hemorrhage, and
tetany (a sign of hypocalcemia associated w damage to the parathyroids. Or
thyroid storm.
Immediately after thyroidectomy, it is especially important to monitor
respiratory status, level of consciousness, wound drainage or bleeding, voice
quality, comfort, neuromuscular irritability (muscle twitching, spasms; calcium).
Chvostek sign
(facial twitch).
Trousseau sign
(carpopedal spasm)
If hypothyroidism isn’t treated early during infancy causes
permanent retardation of physical and mental development (cretinism)
refers to edema that develops in the hands, face, feet, and area around the eyes
with severe, long-term hypothyroidism
Myxedema
Examples of foods that are goitrogens (suppress thyroid)
soybeans, turnips, and rutabagas
The incidence of hypothyroidism is 10 to 20 times higher in iodine-deficient parts
of the world
Hypothyroidism caused by pituitary or hypothalamic disorders is called
secondary hypothyroidism.
Symptoms of hypothyroidism:
headaches, constipation, menstrual disorders, numbness and tingling in the arms
and legs, and intolerance to cold. The pulse tends to be slow and dyspnea may be
present. Lethargy. Weight gain.
Hypothyroidism is diagnosed based on
the laboratory determination of free T4 (low) and TSH
Severe, untreated hypothyroidism can progress to
myxedema coma; 3 signs of it are:
hypothermia, hypotension, and hypoventilation.
Hypothyroidism is treated with hormone replacement therapy, most commonly
levothyroxine (Synthroid
If med has to be changed you should:
get tsh levels
With levothyroxine immediately report:
chest pain
Opioids, sedatives, and tranquilizers can precipitate potentially fatal myxedema
coma in a severely hypothyroid person.
_______ rises if thyroid cancer recurs
Thyroglobulin
secretion of excess PTH is called
hyperparathyroidism.
It is caused most often by a tumor called an
adenoma
High levels of PTH cause calcium
to shift from the bones into the bloodstream, increasing calcium levels
Side affects of hyperparathyroidism
brittle bones, urinary calculi, dysrhythmias, hypertension
What does hyperparathyroidism do to your reflexes?
theyre hypoactive
Treatment of hyperparathyroidism:
high fluid intake to dilute the urine. Calcium intake may be restricted. Sodium and
phosphorus replacements may be ordered. NS to lower calcium if needed
Calcitonin (Calcimar), bisphosphonates (zoledronate), and estrogen inhibit the
release of calcium from bones.