Overview
DESCRIPTION Cosyntropin for Injection is a sterile lyophilized powder in vials containing 0.25 mg of Cosyntropin and 10 mg of mannitol to be reconstituted with 1 mL of 0.9% Sodium Chloride Injection, USP. Administration is by intravenous or intramuscular injection. Cosyntropin is a 1 to 24 corticotropin, a synthetic subunit of ACTH.
Mechanism of Action
CLINICAL PHARMACOLOGY Cosyntropin for Injection 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 to 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 residues. For example, the decrement from 20 to 19 results in a 70% loss of potency. The pharmacologic profile of Cosyntropin for Injection is similar to that of purified natural ACTH. It has been established that 0.25 mg of will stimulate the adrenal cortex maximally and to the same extent as 25 units of natural ACTH.
Indications
- INDICATIONS AND USAGE Cosyntropin for Injection is intended for use as a diagnostic agent in the screening of patients presumed to have adrenocortical insufficiency. Because of its rapid effect on the adrenal cortex it may be utilized to perform a 30-minute test of adrenal function (plasma cortisol response) as an office or outpatient procedure, using only 2 venipunctures (see DOSAGE AND ADMINISTRATION section). Severe hypofunction of the pituitary - adrenal axis is usually associated with subnormal plasma cortisol values but a low basal level is not per se evidence of adrenal insufficiency...
Common Doses
- 0.75 mg
- 7 mL
- 0.25 mg
- 1 mL
Dosage
DOSAGE AND ADMINISTRATION Cosyntropin for Injection may be administered intramuscularly or as a direct intravenous injection when used as a rapid screening test of adrenal function. It may also be given as an intravenous infusion over a 4 to 8 hour period to provide a greater stimulus to the adrenal glands. Doses of Cosyntropin for Injection 0.25 to 0.75 mg have been used in clinical studies and a maximal response noted with the smallest dose. A suggested method for a rapid screening test of adrenal function has been described by Wood and Associates (1).
Contraindications
- CONTRAINDICATION The only contraindication to Cosyntropin for Injection is a history of a previous adverse reaction to it.
Side Effects
- ADVERSE REACTIONS Since Cosyntropin for Injection is intended for diagnostic and not therapeutic use, adverse reactions other than a rare hypersensitivity reaction are not anticipated. A rare hypersensitivity reaction usually associated with a pre-existing allergic disease and/or a previous reaction to natural ACTH is possible. Symptoms may include slight whealing with splotchy erythema at the injection site. There have been rare reports of anaphylactic reaction.
Interactions
- Drug Interactions Corticotropin may accentuate the electrolyte loss associated with diuretic therapy.