Cosyntropin: what the FDA reviewed for dog products
1 Freedom of Information summary from the FDA Center for Veterinary Medicine for products containing Cosyntropin, as typed records: every value below is followed by the verbatim passage it was taken from. Species as stated by each summary: Dogs.
Products
- CosACTHen® (NADA/ANADA 141-576)
CosACTHen® NADA 141-576, Original approval, December 18, 2025; sponsor Dechra Veterinary Products LLC; species: Dogs; foi_id 17830; FDA PDF
Indication
Evaluation of adrenal function in dogs (ACTH stimulation test).
Dose regimen
0.25 mg (1 mL) per dog weighing 10-110 lbs (4.5-50 kg), Intravenous or intramuscular injection, single injection for the ACTH stimulation test, Dose selected from literature; minimum effective dose 0.005 mg/kg; maximum exposure dose 0.056 mg/kg.
The dose is 0.25 mg (1 mL) per dog weighing 10-110 lbs (4.5-50 kg), administered by intravenous or intramuscular injection, with the purpose of performing the adrenocorticotropic hormone ACTH stimulation test.
Target-animal safety
dose multiples 1X (IV), 3X (IV), 5X (IV), 1X (IM), 2X (IM); duration Three weekly injections (Days 0, 7, 14); necropsy Day 16; animals 16 males and 16 females (Beagles, 5 to 6 months).
Study Animals: Thirty-two healthy Beagle dogs (16 males and 16 females), 5 to 6 months of age, and weighing 7.0 to 9.5 kg on the day of the first injection.
| Finding | Quote |
|---|---|
| Transient salivation during/after dosing in six of eight 5X IV dogs at the third dose. | Clinical signs related to cosyntropin injection administration included transient salivation observed during and/or immediately after dosing in six of eight dogs in the 5X IV-dosed group during the third dose. |
| Hypersensitivity reaction in one 5X IV dog at the third injection (salivation, injected mucous membranes, inguinal erythema, facial edema, tachycardia), recovered without intervention. | One of the 5X IV-dosed dogs had a hypersensitivity reaction to its third injection. The reaction started within three minutes of dosing and included: transient salivation, injected mucous membranes, inguinal erythema, facial edema, and tachycardia. |
| Vomiting within an hour of dosing in one of four 1X IV dogs and three of eight 5X IV dogs. | One of four 1X IV-dosed dogs and three of eight 5X IV-dosed dogs vomited once within an hour of dosing. |
| Microfocal mineralized deposits in the stomach fundus in 14 of 32 dogs (one control); prostatic interstitial inflammation in 3 of 16 males; relationship to drug unknown. | On histopathology examination, there was minimal to mild microfocal mineralized deposits in the fundic glands and/or lamina propria of the stomach fundus in 14 of 32 dogs; one of which was a control dog. Three of 16 males had non-suppurative interstitial inflammation of the prostate; no control dogs had this change. |
| Conclusion: adequate margin of safety at 1X, 3X, 5X IV and 1X, 2X IM of the 0.056 mg/kg maximum exposure dose; salivation, hypersensitivity and vomiting are possible drug-related reactions. | Cosyntropin injection demonstrated an adequate margin of safety when administered as three weekly IV injections at 1X, 3X, or 5X the maximum exposure dose of 0.056 mg/kg or by IM injections at 1X or 2X the maximum exposure dose. |
Effectiveness
Pivotal pharmacodynamic laboratory study (Study D24006, final formulation, GLP): masked, randomized, saline-controlled parallel design; CosACTHen 0.005 mg/kg IM once vs saline in healthy female beagles; serum cortisol pre-dose and 30, 60, 90 minutes post-dose; positive response rates compared by Fisher's exact test.; n = sixteen (8 CosACTHen, 8 saline); primary endpoint: Positive response (serum cortisol greater than 6.5 µg/dL after dosing, from a pre-dose value of 0.5 - 6.5 µg/dL) at 30, 60 and 90 minutes; result: All CosACTHen dogs and no saline dogs responded at every timepoint (p = 0.0002 at each); mean serum cortisol 9.2, 12.9 and 11.8 µg/dL at 30, 60 and 90 minutes vs 1.9 µg/dL pre-dose; no adverse reactions.
The sponsor conducted a well-controlled laboratory study in sixteen healthy, female beagle dogs intramuscularly administered CosACTHen® (8 dogs) or saline (8 dogs). Plasma cortisol concentrations were determined 30 minutes prior to dosing and at 30, 60, and 90 minutes after CosACTHen® or saline administration. All dogs in the CosACTHen® group had a positive response (defined as a serum cortisol concentration greater than 6.5 μg/dL after dosing) at 30, 60, and 90 minutes. No dogs in the control group had a positive response.
Adverse reactions
| Term | Treated | Control | Quote |
|---|---|---|---|
| Vomiting within 8 hours (field study NAH-08-0003, non-final formulation) | Two dogs | Adverse Reactions: Two dogs vomited within 8 hours after cosyntropin injection administration. One dog developed a hematoma following IV administration of cosyntropin injection. | |
| Hematoma following IV administration (field study NAH-08-0003) | One dog | Adverse Reactions: Two dogs vomited within 8 hours after cosyntropin injection administration. One dog developed a hematoma following IV administration of cosyntropin injection. | |
| Any adverse reaction (pivotal laboratory study D24006) | none reported | none reported | Adverse Reactions: No adverse reactions were reported during the study. |
Extraction notes: Original NADA (2025). No pharmacokinetic data (cortisol response is pharmacodynamic and recorded under effectiveness). Effectiveness also supported by a 2008 laboratory study (NAH-07-0036, 32 dogs, non-final formulation, IM and IV) and a randomized unmasked field study (NAH-08-0003, 119 dogs suspected of hypo- or hyperadrenocorticism, 107 evaluable, non-final formulation, 0.25 mg/dog IM or IV) with diagnostic accuracy 100% for hypoadrenocorticism and 69.8% (IM) / 70.5% (IV) for hyperadrenocorticism vs LDDS. The margin of safety study used a non-final formulation; dose multiples are of the 0.056 mg/kg maximum exposure dose (1X IV 0.056, 3X 0.168, 5X 0.280 mg/kg; IM 1X 0.056, 2X 0.112 mg/kg), 4 dogs per group except 8 in the 5X IV group. Foreign post-approval reports: lethargy, anxiety, muscle tremor/weakness, abdominal pain, anorexia, diarrhea, injection site pain/bruising, lameness, hypersensitivity. Field-study adverse reaction counts are written in words in the source ('Two dogs', 'One dog'); the safety population was 119 dogs.
Reproduce: foi_structured_search(query="Cosyntropin") and foi_summary_get(foi_id=...) in dog-geroscience-mcp; dataset foi-summaries-dog (config structured).