Endocrine Disorders Flashcards
anterior pituitary
secretes 6 different hormones, including TSH and adrenocorticotropic hormone (ACTH)
posterior pituitary
secretes 2 hormones –> antidiuretic hormone, oxytocin
where are adrenal glands situated?
sit on top of kidneys
anatomical components of adrenal glands
composed of inner medulla and outer cortex
what does the adrenal medulla secrete?
epi and norepi
what does the adrenal cortex secrete?
–glucocorticoids (Cortisol)
–mineralcorticoids (Aldosterone)
–sex steroids (Androgens)
definition of Cushing Syndrome
a collection of signs and symptoms associated with hypercortisolism
Primary hyperfunction cause
disease of adrenal cortex (Cushing’s syndrome)
Secondary hyperfunction cause
disease of anterior pituitary (Cushing’s disease)
what do exogenous steroids cause?
Cushing’s syndrome
Cortisol functions
–raises blood sugar (opposes insulin)
–protects against the physiologic effects of stress
–suppresses immune and inflammatory processes
–breaks down protein and fat
increased cortisol effect on glucose availability
–glucose intolerance
–hyperglycemia
increased cortisol effect on maintenance of vascular system
–hypertension
–capillary friability
increased cortisol effect on protein breakdown
–muscle wasting
–muscle weakness
–thinning of skin
–osteoporosis and bone pain
increased cortisol effect on fat breakdown
–redistribution of fat to abdomen, shoulders, and face
increased cortisol effect on suppression of immune and inflammatory responses
–impaired wound healing and immune response
–risk for infection
increased cortisol effect on CNS excitability
–mood swings
–insomnia
clinical manifestations of Cushing’s
–red cheeks
–abdominal stretch marks
–pendulous abdomen
–fat pads (Buffalo hump)
–bruise easily
–thin arms and legs
treatment for Cushing’s
treatment depends on cause
–pituitary or adrenal tumor: surgery or radiation
drugs used with Cushing’s
–aminoglutethimide
–ketoconazole
MOA of aminoglutethimide
blocks synthesis of all adrenal steroids
indication of aminoglutethimide (Cytadren)
temporary therapy to decrease cortisol production
effects of aminoglutethimide (Cytadren)
–reduces cortisol levels by 50%
–does not affect the underlying disease process
adverse effects of aminoglutethimide (Cytadren)
–drowsiness
–nausea
–anorexia
–rash
MOA of ketoconazole (Nizoral)
antifungal drug that also inhibits glucocorticoid synthesis
indication for ketoconazole (Nizoral)
adjunct therapy to surgery or radiation for Cushing syndrome
main adverse effect of ketoconazole (Nizoral)
severe liver damage
safety issues with ketoconazole (Nizoral)
–do not take with ETOH or other drugs that harm liver
–do not give during pregnancy (fetal thyroid damage)
definition of Addison disease
disease of the adrenal cortex that causes hyposecretion of all 3 adrenocortical hormones
cortisol = ?
sugar
salt = ?
aldosteron
sex = ?
androgens
etiology of Addison disease
idiopathic, autoimmune, or other
patho of Addison disease
–adrenal gland destroyed
–symptoms when 90% non-functional
–adrenocorticotropin hormone (ACTH) and melanocyte-stimulating hormone (MSH) are secreted in large amounts
early clinical manifestations of Addison disease
–anorexia
–weight loss
–weakness
–malaise
–apathy
–electrolyte imbalances
–skin hyperpigmentation
symptoms of hypoaldosteronism
–hypotension (decreased vascular tone, decreased CO, decreased circulating blood volume)
–salt craving (decreased serum NA levels, decreased serum K levels, dehydration)
symptoms of hypocortisolism
–hypoglycemia
–weakness and fatigue
–unsuppressed ACTH production
–hyperpigmentation
pharmacology for Addison Disease
–lifelong corticosteroid replacement therapy (adrenal insufficiency)
–glucocorticoid
–hydrocortisone (drug of choice)
–prednisone
–dexamethasone
–some require mineralcorticoid
–fludrocortisone
important issues with pharmacotherapy
–dosing mimics natural release of hormones
–never abruptly stop therapy
–dose will need to be increased during stress
–always maintain emergency supply
–wear Medic Alert bracelet
adrenal medulla disorder
pheochromocytoma
pheochromocytoma
rare tumor of the adrenal medulla that produces excessive catecholamines
risk factor for pheochromocytoma
young-middle age
What does a pheochromocytoma trigger in the body?
SNS stimulation –> excessive release of epi, norepi
symptoms of pheochromocytoma
–HA
–hypertension
–diaphoresis
–tachycardia
drug therapy for pheochromocytoma
–principal cause of hypertension = activation of alpha 1 receptors on blood vessels
–treatment = surgery
–alpha-adrenergic blockers for inoperable tumors, pre-op to reduce risk of HTN
example of alpha-blockers for pheochromocytoma
phenoxybenzamine HCl (Dibenzyline)
indication for phenoxybenzamine HCl (Dibenzyline)
pheochromocytoma
MOA for phenoxybenzamine HCl (Dibenzyline)
long-lasting, irreversible blockage of alpha-adrenergic receptors
drug effects of phenoxybenzamine HCl (Dibenzyline)
lowers BP
adverse effects of phenoxybenzamine HCl (Dibenzyline)
–orthostatic hypotension
–reflex tachycardia
–nasal congestion
–sexual side effects in men
antidiuretic hormone (ADH)
released in response to high serum osmolality and/or hypotension
function of ADH
causes water retention via action in the kidneys
way to remember function of ADH
“ADH–this hormone stops the pee pee”
SIADH
syndrome of inappropriate antidiuretic hormone
SIADH definition
an abnormal production or sustained secretion of ADH
what is SIADH characterized by?
–fluid retention
–serum hypoosmolality and hyponatremia
–concentrated urine
etiology of SIADH
–malignant tumors
–CNS disorders
–drug therapy
–miscellaneous (hypothyroidism, infection)
malignant tumors associated with SIADH
small cell carcinoma of the lung
CNS disorders associated with SIADH
–head trauma
–stroke
–brain tumors
patho of SIADH
increased antidiuretic hormone –> increased water reabsorption in renal tubules –> increased intravascular fluid volume –> dilutional hyponatremia and decreased serum osmolality
serum osmolality in SIADH
low
urine osmolality and specific gravity in SIADH
high
serum sodium in SIADH
low
urine output in SIADH
low
weight in SIADH
gain
water retention in SIADH
retaining pure water without salt
what do symptoms depend on with SIADH?
depend on severity and rate of onset of hyponatremia
symptoms of hyponatremia
–dyspnea
–fatigue
–lethargy
–confusion
–dulled sensorium
–musical twitching
–convulsions
–impaired taste
–anorexia
–vomiting
–cramps
severe symptoms of SIADH
sodium = 100-115 –> irreversible neuro damage
water intoxication
when serum levels of sodium become lower than what is INSIDE the cells
–cells swell
symptoms of water intoxication
–neurologic: confusion, lethargy, coma, death
pharm with SIADH
–not first line of defense
–treatment –> underlying cause
–chronic SIADH = demeclocycline
classification of demeclocycline (Declomycin)
tetracycline broad-spectrum antibiotic
MOA of demeclocycline
interferes with renal response to ADH
adverse effects of demeclocycline
–photosensitivity
–teeth staining
–nephrotoxic
definition of diabetes insipidus
a deficiency of ADH or a decreased renal response to ADH
what is DI characterized by?
excessive loss of water in the urine
two forms of DI
–neurogenic (central)
–nephrogenic
cause of neurogenic DI
hypothalamus or pituitary gland damage
associated disorders with neurogenic DI
–stroke, TBI
–brain surgery
–cerebral infections
etiology of neurogenic DI
–sudden onset
–usually permanent
–neuro origin
etiology of nephrogenic DI
–renal origin
–slow onset
–progressive
cause of nephrogenic DI
–loss of kidney function
–often drug-related
associated disorders of nephrogenic DI
CKD
patho of DI
decreased antidiuretic hormone –> decreased water reabsorption in renal tubules –> decreased intravascular fluid volume –> increased serum osmolality/excessive urine output
serum osmolality in DI
high
urine osmolality and specific gravity in DI
low
serum sodium in DI
high
urine output in DI
high
weight in DI
loss
symptoms of DI
–polyuria
–polydipsia
–dehydration
–electrolyte imbalances
–hypovolemic shock –> death
pharm for neurogenic DI
–synthetic ADH replacement
pharm for nephrogenic DI
–thiazide diuretics
why are diuretics used in someone who is peeing constantly?
paradoxical effect decreases polyuria and increases urine osmolality
desmopressin (DDAVP)
treatment for neurogenic DI
MOA for desmopressin
–synthetic ADH replacement
–anti-diuretic effects
route for desmopressin
–nasal spray
–PO
–IV
–SQ
adverse effects for desmopressin
small doses: none
nasal spray: nasal irritation
large doses: hyponatremia, water intoxication
DI acronym
D: dry
I: I&O, daily weight
L: low specific gravity
U: urinates lots
T: treat=desmopressin
E: rEhydrate
