ACTH Stimulation in Hyperadrenocorticism and Hypoadrenocorticism


The rise in cost for Synacthen has left us gasping, so the following papers evaluating lower doses of Synancthen are useful.


Study one (Aldridge et. al., 2016) determined that cosynthropin (Synacthen) could be given at a dosage of 5 ug/kg for diagnosing hyperadrenocorticism whereas 1 ug/kg is adequate for monitoring during trilostane therapy. 

Note: A dosage of 1 ug/kg is insufficient to diagnose hyperadrenocorticism.


Study two (Latham et. al., 2008) determined that 5 ug/kg was sufficient for assessing adrenal function in hypoadrenocorticoid dogs.

Note: A dosage of 1 ug/kg is insufficient to diagnose hypoadrenocorticism


Reconstituted Synacthen not used at the first test can be aliquoted into smaller units and frozen for future use.  Note that once thawed, the remainder must be discarded.

Be aware that red top tubes cannot be used for storing Synacthen.   Syringes are used by some veterinarians.

Frozen Synacthen not used within 6 months should be discarded.



Reference 1: Comparison of 2 Doses for ACTH Stimulation Testing in Dogs Suspected of or Treated for Hyperadrenocorticism. C Aldridge, E N Behrend, R J Kemppainen, et. al J Vet Intern Med.  2016;30:1637-41

Reference 2: Use of a low-dose ACTH stimulation test for diagnosis of hypoadrenocorticism in dogs. P Lathan, GE Moore, S Zambon, JC Moncrieff. Â J Vet Intern Med.  2008;22:1070-3