Cortrosyn

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Cortrosyn

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Medically reviewed

Marina Burgos

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Cortrosyn

What is Cortrosyn?

Cortrosyn is a synthetic brand-name medication containing cosyntropin as its active ingredient. It is a sterile lyophilized powder that, when reconstituted, is administered via injection.

Mechanism of Action

Cosyntropin is a synthetic subunit of the naturally occurring adrenocorticotropic hormone (ACTH). In a healthy functioning system, ACTH is produced by the pituitary gland to stimulate the adrenal cortex. Once stimulated, the adrenal glands produce various essential hormones, including cortisol and aldosterone.

Cortrosyn mimics the action of natural ACTH. When introduced into the body, it acts on the adrenal cortex to trigger the release of these hormones. Because it is a synthetic derivative containing the first 24 amino acids of the 39-amino acid ACTH chain, it maintains the full biological activity of the natural hormone while reducing the potential for certain types of allergic reactions associated with animal-derived ACTH.

Primary Clinical Use

Cortrosyn is primarily used as a diagnostic agent rather than a long-term treatment. It is the central component of the ACTH stimulation test (sometimes referred to as a cosyntropin test), which helps healthcare providers evaluate the functional capacity of the adrenal glands.

By measuring the levels of cortisol in the blood before and after an injection of Cortrosyn, clinicians can determine if the adrenal glands are responding appropriately to hormonal signals. This process is essential for identifying various types of adrenal insufficiency, such as Addison's disease, or determining if adrenal function has been suppressed by other factors.

Regulatory References

  1. Synthetic ACTH analogue purity and antigenic concerns (NIH/PMC)

What side effects are possible with Cortrosyn?

Possible Side Effects and Safety Information

The safety profile of Cortrosyn (Tetracosactide) is defined primarily by its function as a short-acting diagnostic agent, with most adverse event data derived from post-marketing surveillance. This means that for many reactions, the frequency cannot be reliably estimated according to regulatory standards.

Serious and Acute Adverse Reactions

The most critical officially documented risk is the potential for severe hypersensitivity reactions, including anaphylaxis. Regulatory documents note that fatalities have been reported in rare cases associated with these severe reactions. Such acute events generally manifest rapidly, often within 30 minutes of administration.

Officially Documented Adverse Reactions

Adverse reactions reported post-approval are generally classified by the affected body system. Common reports have included events within Cardiovascular Disorders (e.g., hypertension, bradycardia, tachycardia), Skin and Subcutaneous Tissue Disorders (rash), and General Disorders (peripheral edema).

System-Organ Class Examples of Reported Adverse Reactions
Immune System Disorders Anaphylactic reaction, Hypersensitivity
Vascular Disorders Hypertension
Cardiac Disorders Bradycardia, Tachycardia

Safety Considerations and Restrictions

The drug is formally contraindicated in individuals with a known history of a previous adverse reaction to Cosyntropin or any of its excipients. For specific populations, the regulatory status is defined as Pregnancy Category C, meaning risk cannot be ruled out. Caution is advised during lactation because it is unknown if the drug is excreted in human milk. Furthermore, the label notes that the use of other medications may interfere with the test results, potentially leading to diagnostic inaccuracies.

Overdose and Emergency Response

Overdose and When to Seek Help

Cortrosyn (cosyntropin) is strictly intended for diagnostic use, meaning it is used only to test adrenal function and not for therapeutic treatment. Due to this limited purpose, adverse reactions beyond a rare hypersensitivity reaction are generally not anticipated by regulators.

Overdose situations are primarily characterized by the reporting of various adverse reactions following administration. These reported signs may include cardiovascular changes such as bradycardia (slow heart rate), tachycardia (fast heart rate), and hypertension (high blood pressure), along with peripheral edema (swelling of the extremities).

When Urgent Medical Attention is Required

Immediate medical help is required if a patient experiences signs of a hypersensitivity reaction, which has been documented to include anaphylaxis (a severe, potentially life-threatening reaction). Patients and caregivers should be vigilant for the early signs of a severe reaction, which include:

  • Rash or hives
  • Itching
  • Facial swelling
  • Tightness of the chest
  • Wheezing

If any of these severe signs of hypersensitivity develop, immediate evaluation and treatment by a healthcare provider are necessary. Healthcare professionals must monitor patients for hypersensitivity reactions and treat them as medically needed.

Therapeutic Uses of Cortrosyn

Cortrosyn: Main Uses and Benefits

Quick Facts
Primary Use: Diagnostic agent
Aids in the screening for: Adrenocortical insufficiency
Used in the evaluation of: Adrenal gland function

Cortrosyn is a specialized medication with a primary role as a diagnostic agent. Its main use is in the screening of patients when the physician suspects adrenocortical insufficiency (AI). This condition involves the inadequate production of specific hormones by the adrenal glands.

The medication is administered during a medical test, commonly known as an ACTH stimulation test, to help evaluate the function of the adrenal cortex. The results of this test, when interpreted alongside other clinical information, may assist in establishing a diagnosis of AI in adults and pediatric patients.

By utilizing this diagnostic agent, healthcare professionals can assess the adrenal gland's capacity to respond to stimulation. This assessment is an important step in determining the presence and type of adrenal dysfunction.

Eligibility and Restrictions for Use

The eligibility for using Cortrosyn (Cosyntropin) is defined by official regulatory documentation, primarily establishing its use as a diagnostic agent and defining clear contraindications. This information strictly governs who is permitted to receive the medicine.


Populations That Must Not Use Cortrosyn

Cortrosyn is strictly contraindicated and must not be administered to any patient with a documented history of hypersensitivity to the active substance, cosyntropin, or to synthetic adrenocorticotropic hormone (ACTH). This absolute restriction also applies to known allergies to any inactive ingredients (excipients) in the injection formulation.


Established and Restricted Eligibility

Use is established in a wide age range, including adults and pediatric patients from birth to 17 years, when screening for adrenocortical insufficiency. The regulatory label does not cite specific restrictions based on pre-existing hepatic (liver) or renal (kidney) impairment.

For pregnant women, use is conditional and should be considered only if clearly needed, as safety in this population has not been definitively established. Caution is advised for nursing mothers, as regulators note it is currently unknown whether cosyntropin is excreted into human milk.

What should I know about interactions with other medicines?

Cortrosyn (cosyntropin) is a diagnostic agent used in the ACTH stimulation test, and its primary interactions involve medications that can interfere with the accuracy of the test results, rather than causing direct adverse reactions. To ensure a reliable diagnosis of adrenocortical insufficiency, it's crucial to inform your healthcare provider about all medicines you are taking, including over-the-counter drugs, vitamins, and herbal supplements.

Medications that Interfere with Test Accuracy

Certain medicines can affect plasma cortisol levels, leading to false test results. Your doctor will provide specific instructions on when to temporarily stop these drugs before the test:

Drug Class Effect on Cortisol Levels Pre-Test Instruction (Consult Physician)
Glucocorticoids (e.g., prednisone, hydrocortisone) and Spironolactone May falsely elevate plasma cortisol. Stop on the day of the test. Longer-acting glucocorticoids may require stopping for a longer period.
Estrogen-containing Drugs (e.g., oral contraceptives, hormone replacement therapy) Increase cortisol-binding globulin, which elevates total plasma cortisol. Discontinue 4 to 6 weeks before the test.

Other Interactions

Cortrosyn may also accentuate the electrolyte loss associated with certain diuretic (water pill) therapies. You should inform your doctor if you are taking a diuretic.

Mechanism of Action

Cortrosyn (synthetic ACTH1-24) is a short polypeptide that acts as an agonist for the adrenocorticotropic hormone (ACTH) receptor. Its primary mechanism of action centers on engaging this receptor type, which is found predominantly on the cells of the adrenal cortex.

Agonism at Melanocortin-2 Receptors ( MC2 R)

The drug's action initiates a signaling sequence by binding to the melanocortin-2 receptor ( MC2 R), the specific receptor subtype for ACTH located on the adrenal cortex. This engagement is the initial step in the mechanistic cascade that drives cellular response.


Modulating Adrenal Steroidogenesis Cascade

Binding to the MC2 R triggers a G protein-coupled receptor signaling pathway, leading to increased activity of the enzyme adenylate cyclase and a subsequent rise in intracellular cyclic AMP ( cAMP). This increased cAMP concentration mediates the downstream enzymatic events that activate the steroidogenesis process.


Resulting Physiological Effect: Steroid Hormone Secretion

The cAMP-mediated signaling culminates in the rapid stimulation of the synthesis and secretion of adrenocortical hormones, primarily cortisol and, to a lesser extent, androgens and aldosterone. This direct stimulation of the adrenal gland results in a rapid increase in the circulating levels of these steroid hormones.

Dosage and Administration Information

How to Use Cortrosyn — Administration Guidelines

Cortrosyn (cosyntropin) is administered by a healthcare professional as a diagnostic agent, following a precise, time-sensitive protocol. The guidelines detail preparation, dosing, administration route, and pre-test medication adjustments.

Administration and Dosing

The required dose and method of delivery are specified based on age:

Age Group Recommended Dose Administration Route
Adults 0.25 mg Intravenous (IV) or Intramuscular (IM) injection
Children (2 to 17 years) 0.25 mg IV or IM injection
Children (Birth to <2 years) 0.125 mg IV or IM injection

Preparation and Procedural Steps

  1. Pre-Test Medication Stop: Patients should generally stop glucocorticoids and spironolactone on the day of testing, as these medications may affect test accuracy. Long-acting glucocorticoids may require stopping for a longer period.
  2. Reconstitution: The lyophilized powder must be reconstituted with 1 mL of 0.9% Sodium Chloride Injection, USP. The resulting solution must be visually inspected for particulate matter or discoloration prior to injection.
  3. Blood Sample Collection: A baseline blood sample must be collected just prior to the injection.
  4. Administration and Timing: The appropriate dose is administered via IV or IM injection. For the rapid screening test, a second blood sample is collected for cortisol assessment exactly 30 minutes after the injection.

Note: Any unused portion of the reconstituted solution must be discarded.

Recent Clinical Evidence

Cortrosyn: Recent Clinical Evidence

Cortrosyn (synthetic ACTH/cosyntropin) is primarily used in the rapid adrenocorticotropic hormone (ACTH) stimulation test, which assesses the function of the adrenal glands. This diagnostic procedure measures the adrenal cortex's capacity to produce cortisol in response to the injected synthetic hormone.

Clinical Efficacy in Adrenal Function Assessment

Research has consistently established the role of cosyntropin as the gold standard for diagnosing primary and secondary adrenal insufficiency (Addison's disease or pituitary failure). The test is generally considered reliable and safe when performed under standard clinical guidelines. A typical study involves administering 250 mu g of cosyntropin intramuscularly or intravenously, followed by measuring serum cortisol levels at 30 and 60 minutes.

Recent data emphasize the test's high specificity and sensitivity for detecting adrenal insufficiency, particularly when interpreting results based on established cutoff values for cortisol response. Studies continue to explore and validate lower-dose protocols (1 mu g) for diagnosing mild forms of secondary adrenal insufficiency, although the standard 250 mu g dose remains the most widely accepted method.

Safety and Tolerability Profile

Clinical data indicates that Cortrosyn is well-tolerated in most populations, especially given its use as a single-dose diagnostic agent. The risk of serious adverse events is low. The most frequently reported reactions are localized at the injection site, such as mild pain or redness. Rare reports of hypersensitivity reactions, including anaphylaxis, have been documented, highlighting the need for vigilance during the procedure. However, the overall safety profile aligns with its established use in clinical diagnostics across various patient groups, including children and adults.

Key Studies & References

  1. Cortrosyn (cosyntropin) Injection, powder, lyophilized, for solution - DailyMed (FDA Labeling)
  2. Diagnostic Utility of Low-Dose Cosyntropin Stimulation Test for Central Adrenal Insufficiency

Frequently Asked Questions (FAQ)

Common questions about Cortrosyn (FAQ)

Q: Is Cortrosyn the same as hydrocortisone?

A: No, they are different substances. Cortrosyn is a synthetic peptide that works by stimulating the adrenal glands to synthesize and release their own hormones.

Its function is to trigger the release of cortisol, which is the endogenous (natural) form of hydrocortisone. It is not the same chemical substance as hydrocortisone.


Q: Is Cortrosyn a steroid?

A: Cortrosyn is not classified as a steroid hormone (corticosteroid). It is officially defined as a synthetic polypeptide that mimics the action of the body's natural adrenocorticotropic hormone (ACTH).

Its purpose is to stimulate the adrenal gland to synthesize and secrete cortisol, which is classified as a steroid.


Q: What is 'adrenal insufficiency' that the Cortrosyn test looks for?

A: Adrenal insufficiency is a condition where the adrenal glands, which sit above the kidneys, are characterized by the inadequate release of cortisol and other essential hormones.

Specifically, the Cortrosyn test is used to assess if there is an inadequate production of the steroid hormone cortisol from the outer layer of the adrenal gland, called the adrenal cortex.


Q: What is the difference between primary and secondary adrenal insufficiency in the context of the Cortrosyn test?

A: The Cortrosyn test helps distinguish between the two main types of the condition. Primary adrenal insufficiency is attributed to an impairment of the adrenal glands themselves.

Secondary adrenal insufficiency, in contrast, stems from an issue with the pituitary gland, which is responsible for sending the signal (ACTH) to the adrenals.


Q: Can Cortrosyn cause anxiety or nervousness?

A: Official documents contain reports of adverse events, which have included mood changes such as irritability or anxiety.

It is noted, however, that because the drug's use is limited to a single diagnostic dose, the frequency of these types of effects cannot be reliably estimated.


Q: Are headaches a common side effect of Cortrosyn?

A: Headache has been reported in official documents as a potential adverse reaction following administration.

As with many reported side effects for single-dose diagnostic agents, the frequency of headaches is generally not defined or reliably estimated in regulatory documents.


Q: Is it normal to feel flushed right after getting the Cortrosyn injection?

A: Feeling flushed is listed in official regulatory documentation as a reported adverse effect of Cortrosyn.

If this sensation occurs, the healthcare professional performing the test should be made aware.


Q: Can Cortrosyn cause temporary changes in mood?

A: Official documents contain reports of adverse events, which have included mood changes such as irritability or anxiety.

It is noted, however, that because the drug's use is limited to a single diagnostic dose, the frequency of these types of effects cannot be reliably estimated.


Q: Does Cortrosyn affect sleep patterns?

A: Official adverse reaction reports do not explicitly mention sleep patterns. However, reported psychological effects, such as irritability or anxiety, are listed.

Reported psychological effects are not tied to specific frequencies.


Q: How quickly does the Cortrosyn injection work?

A: Official regulatory information indicates that the body's response is very rapid. In healthy individuals, an increase in plasma cortisol (a key adrenal hormone) is typically observed within 5 minutes of the injection, with levels generally reaching their peak between 45 and 60 minutes.


Q: How long does the effect of Cortrosyn last in the body?

A: The drug is short-acting, which is why it is used for a rapid test. The half-life of the active substance (cosyntropin) in the bloodstream is reported to be approximately 7 to 15 minutes.

Its stimulatory effect on the adrenal glands is typically over within four hours after administration.


Q: What are the main components of the Cortrosyn vial?

A: The active ingredient is cosyntropin, also known as tetracosactide. The vial also contains inactive ingredients, called excipients, which include mannitol and water for injection.

Other components, like glacial acetic acid and sodium hydroxide, may be present to ensure the solution's correct balance and stability.


Q: Are there any specific foods or drinks to avoid before getting a Cortrosyn injection?

A: Regulatory warnings emphasize the need to temporarily stop certain medications that could interfere with the accuracy of the cortisol measurement.

However, there are no specific regulatory warnings regarding the need to avoid particular foods or drinks before receiving the Cortrosyn injection.


Q: Can Cortrosyn interact with common anti-inflammatory drugs?

A: The primary concern for interactions involves medications that can interfere with the accuracy of the diagnostic test.

To ensure accurate test results, temporary discontinuation of drugs in the glucocorticoid class (a type of anti-inflammatory steroid) is often required prior to the procedure to prevent falsely elevated results.


Q: Can having a known thyroid condition impact the use of Cortrosyn?

A: Regulatory warnings advise that caution should be exercised when administering Cortrosyn to patients who have a known history of thyroid disease.


Q: Does Cortrosyn have any long-term side effects listed in official documents?

A: Since Cortrosyn is strictly intended for diagnostic testing and is administered only as a single dose, it is not used for chronic or long-term treatment.

Therefore, long-term side effects are generally not anticipated based on its established use. Serious acute events, like rare hypersensitivity reactions, are the primary focus of official warnings regarding safety.


Q: Is Cortrosyn used for conditions other than testing for adrenal problems?

A: Cortrosyn is formally indicated and approved for use exclusively as a diagnostic agent. Its entire purpose is to screen patients to assess adrenal gland function (adrenocortical insufficiency).

It is not prescribed for therapeutic purposes or for the treatment of other medical conditions.


Q: What is the regulatory status of Cortrosyn (e.g., FDA-approved indication)?

A: According to regulatory agencies, Cortrosyn is formally classified as a Diagnostic Agent. This means its labeled purpose is to aid doctors in diagnosis.

Specifically, it is indicated for the screening of patients with suspected adrenocortical insufficiency.


Q: Why is Cortrosyn often stored refrigerated?

A: The powdered form of Cortrosyn requires specific storage conditions that are often misunderstood. Official product information states it must be stored at room temperature, which is typically between 15 C and 30 C (59 F and 86 F).

The product is required to be protected from both light and freezing temperatures.


Q: Is the Cortrosyn test considered a definitive diagnosis tool?

A: Studies and official information consistently establish the ACTH stimulation test, performed using Cortrosyn, as the 'gold standard' diagnostic procedure.

This means it is the primary and most reliable method used to assess a person's adrenal function and determine if primary or secondary adrenal insufficiency is present.


Q: What is the definition of a 'negative' result from the Cortrosyn test?

A: The official test interpretation defines a subnormal or 'negative' result based on the patient's cortisol level following the injection.

This response is typically indicated when the peak plasma cortisol level does not rise above a specific cutoff, such as 18 micrograms per 100 mL, at the 30-minute mark.


Q: What is the definition of a 'normal' response to Cortrosyn?

A: The official test interpretation defines a 'normal' response based on the patient's cortisol level following the injection.

A normal response is generally considered to be an approximate doubling of the basal cortisol level, with the 30-minute plasma cortisol level typically exceeding a specific benchmark, such as 18 micrograms per 100 mL.


Q: Do studies exist about Cortrosyn use in older adult populations?

A: Regulatory labels note that the maximum dose used for adults is also applicable to the geriatric population (patients over 65 years old).

However, official documentation acknowledges a current lack of specific data regarding the safety and use of the drug in this older adult population.


Q: Are there research studies comparing the Cortrosyn test to older methods?

A: Research has focused on the quality and consistency of the synthetic drug itself. Official documents note that because cosyntropin is a synthetic compound, it avoids the variability and potential issues, such as allergic or antigenic concerns, that were associated with older hormone extracts derived from animal sources.

How should Cortrosyn be stored and disposed of?

The lyophilized powder form of Cortrosyn (cosyntropin) should be stored at room temperature, typically between 15 C and 30 C (59 F and 86 F). The product must be protected from light and freezing.

Once the powder has been reconstituted with the appropriate diluent, the resulting solution should not be retained for later use, as its stability is limited. Reconstituted Cortrosyn should be inspected visually for particulate matter or discoloration before injection and is generally intended for immediate use in diagnostic procedures.

For disposal of unused medicine, containers, and other related materials, it is essential to follow all federal, state, and local regulations. Do not dispose of unused portions down the drain or in household trash unless instructed to do so by a healthcare provider or official guidelines.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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