Description
Cosyntropin is a synthetic polypeptide that consists of amino acid residues 1 through 24 of
human ACTH, but that has the full biological activity of its parent. Because it is of synthetic
origin, it is less allergenic than ACTH of natural origin. Cosyntropin is used as a diagnostic
agent in the screening of patients suspected of having adrenocortical insufficiency. Normally,
parenteral administration of cosyntropin acts rapidly on the adrenal cortex to effect release of
plasma hydrocortisone; when performing the test, the hydrocortisone levels are compared to a
control blood sample taken earlier.
Chemical Properties
White or yellow, amorphous powder.
Uses
Hormone (adrenocorticotropic).
Definition
ChEBI: A synthetic peptide that is identical to the 24-amino acid segment at the N-terminal of adrenocorticotropic hormone (corticotropin). A segment similar in all species, it contains the biological activity that stimulates production of cort
costeroids in the adrenal cortex. It is used diagnostically to investigate adrenocortical insufficiency.
Indications
Cosyntropin (Cortrosyn) is a polypeptide that consists
solely of the first 24 amino acids of corticotropin. It appears
to offer an advantage over the naturally occurring
hormone in that it has a longer duration of action and
lacks the antigenic portion of corticotropin. Although
the short cosyntropin test is recognized as a valid
screening test to assess adrenocortical insufficiency, the
overnight metyrapone test or insulin hypoglycemia test
may prove more sensitive.
Brand name
Cortrosyn (Amphastar).
General Description
Cosyntropin (Cortrosyn) is a syntheticpeptide containing the first 24 amino acids of natural corticotropin.Cosyntropin is used as a diagnostic agent to testfor adrenal cortical deficiency. Plasma hydrocortisone concentrationis determined before and 30 minutes after theadministration of 250 g of cosyntropin. Most normal responses result in an approximate doubling of the basalhydrocortisone concentration in 30 to 60 minutes. If the responseis not normal, adrenal insufficiency is indicated.Such adrenal insufficiency could be a result of either adrenalor pituitary malfunction, and further testing is requiredto distinguish between the two. Cosyntropin (250 μg infusedwithin 4–8 hours) or corticotropin (80–120 U/day for3–4 days) is administered. Patients with functional adrenaltissue should respond to this dosage. Patients who respondaccordingly are suspected of hypopituitarism, and the diagnosiscan be confirmed by other tests for pituitary function.Patients who have Addison disease, however, show little orno response.
Biological Activity
Tetracosactide Acetate (SR-TA) stimulates the release of corticosteroids such as cortisol from the adrenal gland. It is absorbed into a zinc phosphate complex, which ensures the sustained release of the active substance from the intramuscular injection site. SR-TA is currently used to manage ulcerative colitis, Crohn's disease, juvenile/adult rheumatoid arthritis, and osteoarthrosis[1].
Biochem/physiol Actions
Activates G proteins.
Side effects
Common side effects of cosyntropin may include:
an allergic reaction (hives; difficult breathing; swelling of your face, lips, tongue, or throat);
fast or slow heartbeats;
increased blood pressure;
rash;
swelling in your hands or feet.
Veterinary Drugs and Treatments
Cosyntropin is used primarily as an alternative to ACTH to test for
adrenocortical
insufficiency (Addison’s), or hyperadrenocorticism,
particularly in animals who have reacted immunologically
to corticotropin
in the past or if ACTH gel is unavailable.
References
[1] F. Iuliano, M. Rossi, Eleonora Iuliano. “Adding Slow Release Tetracosactide Acetate to Eltrombopag Improves Haematological Response in ITP Patients with Platelet-Count Fluctuation.” Blood (2018).
