Approved indications: Cortrosyn is approved only as a diagnostic agent, used with blood tests to assess adrenal function and help diagnose primary and secondary adrenal insufficiency in adults and children from birth.

Off-label uses: Clinicians may use different dosing protocols (such as low-dose or prolonged infusion tests) or administer Cortrosyn during specialized procedures like adrenal vein sampling; these uses rely on clinical studies and expert practice but are not separately FDA-approved indications.

Efficacy expectations: In people with normal adrenal function, cortisol levels begin to rise within minutes and typically peak about 30–60 minutes after injection, often at least doubling from baseline or reaching a lab-defined cutoff; the Cortrosyn (ACTH) stimulation test is considered a standard, reliable first-line screen compared with more complex tests such as the insulin tolerance or metyrapone tests.

Typical dosing and how it is given: For adults, the usual dose is 0.25 mg Cortrosyn given once by intravenous (IV) or intramuscular (IM) injection; for children, 0.125 mg is used from birth to under 2 years and 0.25 mg from 2 to 17 years, also by IV or IM injection.

How the test is performed: A healthcare professional draws a baseline blood sample, gives the Cortrosyn injection into a vein or muscle, then draws additional blood samples—commonly at 30 and 60 minutes—to measure cortisol levels; the test is often scheduled in the morning and may or may not require fasting depending on local protocols.

Special dosing instructions: Your clinician may adjust or stop certain medicines before the test (for example, glucocorticoids and spironolactone on the day of testing, and estrogen-containing medicines several weeks in advance) and will ask you to remain in the clinic for monitoring until the blood draws and observation period are complete.

Missed dose: Because Cortrosyn is given only in a supervised setting, a “missed dose” usually means a missed appointment; in that case, contact the clinic to reschedule rather than trying to obtain or use the drug yourself.

Overdose: Accidental extra dosing is uncommon, but could cause stronger or more prolonged changes in blood pressure, heart rate, or fluid retention; if an overdose is suspected, medical staff will monitor and treat as needed, and if you are outside a medical setting you should seek emergency care or contact poison control immediately.

Common side effects: Most people tolerate a single Cortrosyn injection well, but some may experience brief flushing, feeling warm, nausea, headache, dizziness, injection-site discomfort, or temporary changes in blood pressure or heart rate, usually beginning during or soon after the injection and resolving within hours.

Serious or rare adverse effects: Rarely, Cortrosyn can cause severe allergic reactions including anaphylaxis (trouble breathing, wheezing, swelling of face or throat, hives), significant changes in heart rate or blood pressure, chest pain, or marked swelling of legs or face; these require immediate medical attention and the test is therefore performed where emergency treatment is available.

Warnings and precautions: People with a known allergy to cosyntropin, ACTH, or components of the product should not receive Cortrosyn; those with serious heart disease, uncontrolled high blood pressure, or a history of severe allergies should be monitored closely during testing.

Special populations: Cortrosyn is approved for use from birth through adulthood; available experience in pregnancy and breastfeeding has not shown clear harm, and the brief single-dose exposure is generally considered acceptable when testing for suspected adrenal insufficiency, but decisions are individualized.

Safety vs similar drugs: Because Cortrosyn is typically given as a one-time small injection only for testing, it has far fewer long-term systemic risks than chronic steroid therapy or long-acting ACTH gel products, though the immediate allergy and cardiovascular risks still require monitoring.

Side-effect reporting and safety updates: Patients can report side effects to their healthcare professional and to the FDA MedWatch program (online or by calling 1-800-FDA-1088), and up-to-date safety communications are available on the FDA’s drug safety website.

Drug and supplement interactions: Medicines that change cortisol levels or binding can alter Cortrosyn test results, including glucocorticoids (such as prednisone or hydrocortisone), spironolactone, estrogen-containing therapies (birth control pills, hormone replacement), drugs that inhibit steroid production (such as ketoconazole, etomidate, metyrapone, mitotane, or megestrol), and drugs that speed cortisol breakdown (such as phenytoin or rifampin); your clinician may adjust these before testing.

Foods, alcohol, and lifestyle factors: There are no major direct interactions with specific foods or alcohol for a single diagnostic dose, but heavy alcohol use, severe stress, or acute illness can affect cortisol levels, so you should follow any preparation instructions your healthcare team provides.

Medical conditions requiring caution: A history of severe allergic reactions to ACTH or cosyntropin is a contraindication; significant heart disease, uncontrolled hypertension, or fluid overload warrant close monitoring; conditions that change cortisol-binding proteins (such as pregnancy, oral estrogen use, liver disease, or nephrotic syndrome) are not usually unsafe for the injection but can make interpretation of results more complex.

Monitoring needs: During and shortly after the injection, staff typically check blood pressure, heart rate, and symptoms of allergy while obtaining timed blood samples for cortisol (and sometimes aldosterone or other hormones), and additional lab tests such as electrolytes may be ordered based on the suspected condition.

Q: What is Cortrosyn used for?
A: Cortrosyn is used as part of the ACTH (cosyntropin) stimulation test, in which a single injection is given and blood cortisol levels are measured to see whether the adrenal glands are making enough hormone, helping diagnose adrenal insufficiency and related problems.

Q: Is Cortrosyn a steroid or the same as taking cortisol?
A: No, Cortrosyn is not a steroid; it is a synthetic form of the ACTH hormone fragment that briefly stimulates your own adrenal glands to release cortisol, rather than supplying cortisol directly like steroid pills do.

Q: How should I prepare for a Cortrosyn test—can I eat or take my medicines?
A: Preparation varies by center, but the test is usually done in the morning and your doctor may ask you to fast for a few hours and to stop or adjust certain medicines such as steroids, spironolactone, or estrogen; always follow the specific instructions given by your clinic.

Q: How long do the effects of Cortrosyn last and when will I get results?
A: The drug itself acts for a short time, with cortisol levels typically peaking 30–60 minutes after the injection and then falling over the next few hours, while laboratory results are usually available within hours to a few days depending on the facility.

Q: Is Cortrosyn safe during pregnancy or breastfeeding?
A: Available experience suggests that a single diagnostic dose of Cortrosyn has not been linked to specific problems in pregnancy or breastfeeding, and because untreated adrenal insufficiency can be dangerous, testing is generally recommended when needed, with your care team weighing risks and benefits for your situation.

Storage: Cortrosyn vials are usually kept in clinics or hospitals at controlled room temperature (68–77°F/20–25°C), protected from light and stored in the original carton; patients rarely need to store this medicine at home.

After mixing: Once the powder is mixed with saline, the clear solution is intended for immediate use and any unused portion should be discarded; it should not be saved, refrigerated for later use, or frozen.

Disposal: Used vials, needles, and syringes should be placed in an approved sharps container and disposed of through a clinic, pharmacy, or community take-back program, not in household trash or recycling.