Tetracosactide acetate

Absorption

Rapidly absorbed following intramuscular administration.

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.

The Uses of Tetracosactide acetate

Hormone (adrenocorticotropic).

The Uses of Tetracosactide acetate

Adrenocorticotropic Hormone (1-24), human is used in the treatment of West syndrome. It activates G proteins. It stimulates secretion of glucocorticoid steroid hormones from adrenal cortex cells. It also enhances transcription of mitochondrial genes.

The Uses of Tetracosactide acetate

Adrenocorticotropic Hormone Fragment 1-24 human, rat, has been used in corticosterone enzyme immunoassay and to induce color change in frogs.

Indications

For use as a diagnostic agent in the screening of patients presumed to have adrenocortical insufficiency.

Background

Tetracosactide (also known as Cosyntropin) is a synthetic peptide that is identical to the 24-amino acid segment (sequence: SYSMEHFRWGKPVGKKRRPVKVYP) at the N-terminal of adrenocorticotropic hormone. ACTH (1-24), a segment similar in all species, contains the biological activity that stimulates production of corticosteroids in the adrenal cortex. Tetracosactide exhibits the same activity as natural ACTH with regard to all its biological activities. The complex results in a product whose absorption in man is effected over a longer period of time as compared to corticotropin. Therefore, therapy may be maintained with less frequent administration.

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.

Pharmacokinetics

Cosyntropin exhibits the full corticosteroidogenic activity of natural ACTH. Various studies have shown that the biologic activity of ACTH resides in the N- terminal portion of the molecule and that the 1-20 amino acid residue is the minimal sequence retaining full activity. Partial or complete loss of activity is noted with progressive shortening of the chain beyond 20 amino acid residue. For example, the decrement from 20 to 19 results in a 70% loss of potency. The pharmacologic profile of Cosyntropin is similar to that of purified natural ACTH. It has been established that 0.25 mg of Cosyntropin will stimulate the adrenal cortex maximally and to the same extent as 25 units of natural ACTH. Cosyntropin has less immunogenic activity than ACTH because the amino acid sequence having most of the antigenic activity of ACTH, i.e., amino acids 25-39, is not present in cosyntropin. The extra-adrenal effects which natural ACTH and Cosyntropin have in common include increased melanotropic activity, increased growth hormone secretion and an adipokinetic effect. These are considered to be without physiological or clinical significance.

Side Effects

Common side effects of Tetracosactide acetate 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.

Metabolism

Not Available

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).