Acromegaly
-patho
Overproduction of Growth Hormone
(GH)
Usually from a benign pituitary tumor- leads to overgrowth of bones and soft tissues
Acromegaly in adults vs. children
Adults: growth plates are fused: bones thicken
Children: long bone growth plates are not fused: leads to Giantism due to increased bone length
How is hyperpituitary-acromegaly diagnosed?
High IGF-1: matches/reflects GH levels
CT scan/MRI
OGTT: normally, GH should decrease in response to insulin rising for glucose
In Acromegaly, the GH does not decrease
How does acromegaly present in adults?
Enlarged pituitary: HA, visual problems
Slanted forehead, coarse facial features, protruding jaw, enlarged bones of hands and feet
How is acromegaly treated?
Surgical removal of pituitary tumor
Radiation therapy
Drug therapy
Octreotide
-MOA
-Schedule/route
-Measure what lab?
-Risk for?
Drug for acromegaly
-Antagonizes GH effects
-Give SQ 3x/week
-Measure GH levels every 2 weeks until optimal dose is found
-Risk for gallstones
Hypopituitarism
Treatment?
Decrease in one or more of the pituitary hormones
Surgery/radiation with lifelong hormone therapy
Somatropin
-purpose?
-how is dose adjusted?
-route/schedule?
-AE?
Drug given for low GH from hypopituitarism in children
Synthetic GH
Dosing adjusted via IGF-1
Daily SQ injection
AE: fluid retention, myalgia, joint pain, HA
-usually well tolerated and effective
SIADH
-patho
-manifestations
-Abnormal lab value
High ADH released despite no need to raise BP
Dilutional hyponatremia: muscle cramps, pain, weakness
Initially: thirst, dypsnea on exertion, fatigue
Low UOP, weight gain w/out edema (from fluid retention)
How is SIADH diagnosed?
Measure urine osmolality and serum osmolality at the same time: they should be congruent
-if one if high, the other should be high
SIADH: the urine osmolality is HIGH and the plasma osmolality is LOW
-sodium is also LOW
In mild cases of SIADH, what is often the only treatment?
Fluid restriction: 800-1000 mL/day
What medication can be given for SIADH?
Furosemide
-only safe if sodium is 125+
How is severe hyponatremia from SIADH treated?
IV hypertonic saline (3% NaCl) is slowly infused
-avoid raising sodium quickly
Fluid restriction to 500 mL/day
What fluid restriction is recommended for chronic SIADH?
800-1000 mL/day
Diabetes Insipidus
-patho?
-2 types?
Opposite of SIADH
-low/deficient ADH
-decreased renal response to ADH
Nephrogenic: inadequate renal response to ADH (problem in kidneys)
Central: interference with ADH synthesis/transport/release (problem in pituitary)
What do the lab values for Diabetes Insipidus look like?
High UOP, high plasma osmolality, low urine osmolality
how does Diabetes Insipidus present?
2-20 L UOP/day : LOTS of urine
Low urine specific gravity, high serum osmolality
Polydipsia-compensation for fluid loss
Fatigue from nocturia
General weakness
Severe dehydration: low BP, tachycardia, hypovolemic shock
Severe hypernatremia: CNS symptoms: irritability, mental dullness, coma
How is Diabetes Insipidus diagnosed?
Water deprivation test
-no water for 4-6 hours
-normally, UOP would decrease
-In DI: UOP still high
How is a Diabetes Insipidus diagnosis differentiated into Central or Nephrogenic
Give ADH
If Central, UOP will be normla
If Nephrogenic, nothing improves
How is Central DI treated?
Fluids and hormone therapy
Desmopressin: an ADH analog
How is Nephrogenic DI treated?
Dietary: low sodium
Thiazide diuretics: improve kidney response to ADH
Hormone therapy is ineffective, since kidneys won’t respond
