Cosyntropin (Synthetic Corticotropin)

( Synthetic Corticotropin ) Pronunciation: (KOE-sin-TROE-pin)Class: Adrenalcortical steroid

Trade Names:Cortrosyn- Injection, lyophilized powder for reconstitution 0.25 mg

Trade Names:Cosyntropin- Injection, solution 0.25 mg/mL


Exhibits full corticosteroidogenic activity of natural corticotropin, stimulating the adrenal cortex to produce and secrete adrenocortical hormones.

Indications and Usage

Diagnostic testing of adrenal function.


Standard considerations.

Dosage and Administration

Adults and Children older than 2 yr of age

IM/IV (direct injection) 0.25 to 0.75 mg. IV infusion 0.25 mg in dextrose 5% in water or saline 0.9% administered at 0.04 mg/h over 6 h.


Cortrosyn may be administered IM or IV; cosyntropin must be administered by IV only.

Children 2 yr of age and younger

IM/IV 0.125 mg often will be sufficient.

General Advice

  • Do not allow cosyntropin to mix with blood or plasma infusions.
  • Reconstituted preparations should not be retained.
  • For IM administration, reconstitute 0.25 mg of Cortrosyn in solvent (1 mL ampule of sodium chloride 0.9% injection) and inject intramuscularly.
  • For IV administration, reconstitute cosyntropin with 2 to 5 mL of sodium chloride 0.9% injection. For administration as an IV infusion, cosyntropin 0.25 mg may be added to glucose or saline solutions.
  • Cosyntropin: Do not administer by IM; may be administered as a direct IV injection or as an IV infusion.
  • Cortrosyn may be administered IM, as a direct IV injection, or as an IV infusion.
  • Cosyntropin can be injected IV over a 2-min period. When given as an IV infusion, give at a rate of approximately 40 mcg/h over a 6-h period.



Store at 59° to 86°F.


Store refrigerated at 36° to 46°F; protect from light and freezing.

Drug Interactions


May antagonize anticholinesterase effects in myasthenia gravis.


May decrease pharmacologic effect of cosyntropin.


May decrease pharmacological effect of cosyntropin.


Corticotropin may accentuate the electrolyte loss associated with diuretic therapy.


May increase clearance and decrease therapeutic efficacy of cosyntropin.


Pharmacologic effects may be decreased by cosyntropin; avoid coadministration.


Coadministration is contraindicated.


Potential for increased risk of maternal pulmonary edema when coadministered with cosyntropin.


May require reduced dosage of warfarin; monitor INR closely and adjust dose as needed.

Laboratory Test Interactions

None well documented.

Adverse Reactions


Rare hypersensitivity (eg, slight whealing with splotchy erythema at injection site).



Plasma cortisol concentrations

Measure plasma cortisol concentrations prior to and 30 min after administration. Collect blood sample of 6 to 7 mL in heparinized tube.

Urinary steroids

Alternatively, measure urinary steroids before and after IV infusion.


Category C .




Exhibits slight immunologic activity but is less likely to cause reactions than natural ACTH.

Concomitant therapy

Patients taking cortisone or hydrocortisone on the test day and patients taking spironolactone may exhibit abnormally high basal plasma cortisol levels. A decrease in plasma cortisol values following a stimulating dose of cosyntropin in patients taking cortisone or hydrocortisone may be seen, while a normal response is expected in patients taking spironolactone.

Patient Information

  • Explain purpose of the test.
  • Emphasize importance of lab tests.
  • Instruct patients taking corticosteroids or aldosterone to omit doses on day of test.

Copyright © 2009 Wolters Kluwer Health.