If a doctor has ordered testing for possible adrenal insufficiency, cosyntropin may be part of that workup. It is a diagnostic agent, not a treatment, and its role is narrowly defined by its FDA label.
Key takeaways
- Cosyntropin is classified as an adrenocorticotropic hormone used for diagnostic testing.
- It is approved to help screen for adrenocortical insufficiency by measuring plasma cortisol response.
- The approved brand name is Cosyntropin.
- Over 90 registered trials have studied cosyntropin or involved it as a testing tool.
- Reported adverse events span pregnancy-related exposure reports, low blood sugar, low blood pressure, and respiratory symptoms.
What Cosyntropin Is
Cosyntropin belongs to a drug class known as adrenocorticotropic hormones. It is a synthetic compound built to act like the natural hormone that signals the adrenal glands. Its identity is catalogued under PubChem CID 16129617.
What Cosyntropin Is Approved For
Cosyntropin is approved as a diagnostic agent to screen patients suspected of having adrenocortical insufficiency. It works by prompting a rapid adrenal cortex response, allowing clinicians to measure plasma cortisol over a short test window, often around 30 minutes, using just two blood draws. The label notes that a normal basal cortisol level does not rule out insufficiency, since some patients only show abnormal responses under stress. No boxed warning is present on the label. The approved brand is marketed as Cosyntropin.
What the Evidence Shows
Clinical trial registries list 96 studies connected to cosyntropin, though many use it as a diagnostic or research tool rather than as the primary intervention. A completed Phase 2 trial examined dexamethasone for preventing oral chronic graft-versus-host disease, incorporating cosyntropin-based adrenal assessment. A separate early-phase trial exploring longer-term adrenal suppression with low-dose hydrocortisone was withdrawn before completion.
Reported Side Effects
Adverse event reports submitted to FAERS reflect counts of reported reactions, not confirmed incidence or direct causation. The most frequently reported issues relate to pregnancy exposure, including foetal growth restriction (24 reports) and foetal exposure during pregnancy (23 reports). Metabolic and cardiovascular reactions also appear, including hypoglycaemia (20), hypotension (18), and hyperkalaemia (11). Respiratory and general reactions include dyspnoea and pneumonia (13 reports each), along with nausea (12 reports).