Diabetes Inspidus
                             =================

þ Diabetes Insipidus Etiology
 - caused by decreased cAMP or decreased cAMP effect, or decreased
    countercurrent mechanism
 - diuretics
 - low K+
 - Amphotericin B
 - sickle-cell kidney (disease OR trait)
 - congenital renal disease
 - Darvon (propoxyphene) overdose
 - lithium
 - demecocycline
 - amyloid renal disease
 - Sjogren's syndrome
 - hypercalcemia
 - renal failure
 - osmotic diuresis
 - primary DI

þ Primary Diabetes Insipidus
 - sudden onset of DI due to suprasellar tumor, either primary adenoma or
   sometimes a met from breast cancer.
 - usually patient is 10-20 years old
 - three classic phases:
  + polyuria for 5 days
  + inappropriate antidiuresis for 5 days
  + permanent DI

þ Diagnosis of Diabetes Insipidus
 - Water Restriction Test:
  + lock person away from water, ALL water
  + check urine amount, osmolarity, and patient's weight Q1H, and serum
    osmolarity Q4H.
  + endpoints:
   - serum osmo more than 295
   - weight down by 3-5%
   - three urine osmolalities are within 10% of each other (urine osmolality
     has reached a plateau)
  + once endpoint reached, do DDAVP test:
   - give 10 ug (10 micrograms) DDAVP (arginine vasopressin, also known as
     desmopressin, a synthetic analog of ADH) intranasally or ADH 5 units SQ
   - see if there is an ADH response

þ Treatment of Diabetes Insipidus
 - diabenese (chlorpropamide)
 - Tegretol
 - clofibrate