This test has replaced Anti Diuretic Hormone (ADH)

This test is not Medicare Rebateable.

Test cost: $50

This test must be approved by the Chemical Pathologist before sending

Morning samples after 8 hour fast (without water restriction) are recommended unless otherwise stated by Clinician.

Samples are to be spun and aliquoted within 24 hours on collection.

Samples to be sent frozen.

Non-Water deprived, non-fasting adults:  <16.3 pmol/L

Non-water deprived, fasting (>8hrs) adults:  <15.2 pmol/L

Non-water deprived, non-fasting paediatric subjects:  <14.5 pmol/L

For the investigation of diabetes insipidus (DI) and primary polydipsia (PP) in patients with confimed polyuria (>40 mL/kg/d.*

A baseline Copeptin level >21.4 pmol/L is 100% sensitive and specific for nephrogenic diabetes insipidus.

A baseline Copeptin level <2.6 pmol/L with prior fluid deprivation (>8hr) will indicate complete central DI likely

A stimulated Copeptin**  >4.9 pmol/L PP likely and <4.9 pmol/L partial central DI likely (94.0% specificity and 94.4% sensitivity)

_{*Without concurrent diabetes mellitus, hypercalcemia, pregnancy, uncorrected thyroid or adrenal insufficieny, and heart failure; **at sodium levels >147mmol/L following water deprivation.}