Week 1

Question 1

Posterior Pituitary

Answer 1

ADH (Vasopressin) – increases water reabsorption in kidneys, causes vasoconstriction
Oxytocin – promotes milk ejection, uterine contraction and is anti-inflammatory

Question 2

Syndrome of Inappropriate ADH Secretion (SIADH)

Answer 2

• Improper suppression of ADH secretion leads to increase ADH (Inability for the body to produce-h2o retention)
• Hyponatremia caused from ADH induced retention of water. (Aldosterone {H2o in} & Na+ reabsorption-Made in adrenals)
• Normal functioning of aldosterone and natriuretic peptides lead to euvolemic hyponatremia.

Goals of treatments:

• Treatment of the underlying cause
• Raise serum sodium – fluid restriction, saline administration, oral salt tablets
• Medications if hyponatremia is unable to be corrected by methods above.
• Sodium correction depends on severity of hyponatremia and symptoms

Question 3

Hyponatremia Drugs:

Diuretics

Answer 3

Furosemide – Loop diuretic

Amiloride – K sparing diuretic

Question 4

Hyponatremia Drugs:

Vasopressin Receptor Antagonists – severe SIADH, hospital administration

Answer 4

Tolvaptan

Conivaptan

Question 5

Hyponatremia Drugs:

ADH Inhibitors

Answer 5

Demeclocycline

Lithium

Question 6

Treatment Indication – Severe SIADH (urine osmolality > 2x plasma osmolality) or with saline solution

Answer 6

Furosemide (Lasix)

Dosing Adult: 20 - 40mg po BID, used in combination with salt tablets
MOA: Loop Diuretic (STRONGEST-cause the most Hypokalemia & Hyponatremia)
Monitoring: CMP (Na/K), blood pressure, renal function
Tip: some patients will require KCl supplementation; administer on an empty stomach
Main SE: Hypotension, dizziness, headache, hyponatremia, hypokalemia, hyperglycemia, urinary frequency
Avoid combination with the following drugs: Chloral Hydrate, Ethacrynic Acid, Levosulpiride, Mecamylamine

Question 7

Treatment Indication – Severe SIADH (urine osmolality > 2x plasma osmolality) when Furosemide is contraindicated

Answer 7

Amiloride (Midamor)

Treatment Indication – Severe SIADH (urine osmolality > 2x plasma osmolality) when Furosemide is contraindicated
Dosing Adult: 5mg po qd (may increase to 10mg)
MOA: K sparing diuretic
Monitoring: CMP (Na/K), blood pressure, renal function
Tip: administer with food
Main SE: Hypotension, dizziness, headache, hyperkalemia, abdominal pain, hyponatremia
Avoid combination with the following drugs: cyclosporine, spironolactone, tacrolimus

Question 8

Treatment Indication – Severe SIADH (off-label)

Answer 8

Demeclocycline (Declomycin)
(Tetracyclin antibiotic)
ACUTE only!!! (Severe hepatotoxicity)

Dosing Adult: 300-600mg BID
MOA: inhibits the action of ADH, tetracycline ABX
Monitoring: CBC, renal/hepatic function
Tip: administer 1-2 hours before/after food
This medication is NOT to be used for maintenance of chronic SIADH due to toxicity.
Main SE: many side effects, but can cause heptatotoxicty and acute renal failure.

Question 9

Diabetes Insipidus

ADH only no Glucose involvement

Answer 9

Central DI – deficiency of ADH
Nephrogenic DI – normal ADH with renal resistance to ADH action
Patients present with polyuria, nocturia, thirst, hypernatremia.
Normal functioning of aldosterone and natriuretic peptides lead to euvolemic hypernatremia.
Goals of treatments:
Reduce water loss
Avoid over correcting with water retention

Question 10

Treatment Indication – Diabetes Insipidus (central), Dx of Central DI

Answer 10

Desmopressin (dDAVP)
(Synthetic ADH) Used to dx bt central & Nephrogelic Diabetes)

** Give it at night- suppress urination**

Dosing Adult: Intranasal: 5 – 20mcg qd – BID; Oral: 0.05 – 0.1mg BID
MOA: synthetic ADH analog
Monitoring: blood pressure, fluid intake, serum sodium, urine osmolality
Tip: oral can be administered with or without food; administration usually occurs at night initially; aim for partial diuresis control during the day
Main SE: Headache, dizziness, chills, abdominal pain, fluid retention, hyponatremia.
Goal of treatment is to reduce nocturia
Measure serum sodium 1-2 days after initiation and then at 4 days post Tx

Question 11

Treatment Indication – Diabetes Insipidus (nephrogenic) off-label

Answer 11

Hydrochlorothiazide

Thiazide Diuretic-Helps excrete Na+-lots of fluids needed, low Na+ diet

Dosing Adult: 25mg qd – BID
MOA: Thiazide diuretic – induces mild volume depletion which reduces weight and urine output; decreases sodium volumes.
Monitoring: blood pressure, serum electrolytes, BUN, creatinine.
Tip: Used in combination with a low-sodium diet
Main SE: hypotension, dizziness, headache, hypokalemia, hyponatremia, abdominal cramps

Question 12

Growth Hormone Deficiency

Answer 12

Congenital GH deficiency – children only have slightly reduced birth length.
Acquired GH deficiency – children have severe growth failure
Most children are treated with biosynthetic (recombinant) growth hormone via SC administration.
Dosing is dependent on the severity of the condition (less given to more severe cases).
Injections are often given for years, children are monitored every 6-12 months for responsiveness.

Question 13

Treatment Indication – growth failure

Answer 13

Recombinant hGH (Somatropin)

Dosing Child: 20 - 40mcg/kg/day qd SC
MOA: Growth Hormone
Monitoring: growth curve, tanner staging, thyroid function, IGF-1, urine glucose, alk phos, parathyroid hormone
Tip: rotate administration sites to avoid tissue atrophy
Main SE: antibody production, arthralgias, hypertension, edema, hypoglycemia, hypothyroidism, leukemia, muscle pain, weakness.