Informational Sheet: The IACUC has provided a set of guidance documents (Policies, Guidelines, and Informational Sheets) for use when planning animal procedures at the University of Iowa. Informational Sheets provide information about frequently asked questions and represents guidance for best practices. Deviation from the recommendation(s) does not require specific justification.

 

Purpose: The purpose of this document is to provide labs with information about extended-release buprenorphine options, including the use of FDA-approved versus compounded versions.

Extended-release buprenorphine products offer a way to provide opioid analgesia for up to 48 hours with a single subcutaneous injection. 

Use of Extended-Release Buprenorphine Products 

  • Do NOT dilute it as it affects the rate of release
  • MUST be given as a subcutaneous injection
  • Is viscous and may require larger needle sizes (22-23 gauge) for administration
    • May most easily be administered under anesthesia.
  • Administration of small volumes may be aided by drawing up air into the syringe prior to the dose or using low-dead space syringes.
  • Will take time to reach therapeutic levels (30 minutes for mice, up to 8 hours for guinea pigs). May need to administer other analgesia (e.g. regular buprenorphine) to provide pain relief in the interim.
  • Consult with an OAR Veterinarian regarding concerns of dosing and administration

Ethiqa XR

Ethiqa XR the only FDA-approved extended-release buprenorphine product for laboratory animals. It is approved for various rodent species, ferrets, laboratory rabbits, and non-human primates. It is manufactured by Fidelis Animal Health.

Ethiqa XR is a controlled substance obtained under the PI’s DEA license and must be managed like any other controlled drug, including storage, inventory tracking, and disposal.

Note: Caution should be used when administering Ethiqa XR with NSAIDs concomitantly in mice as death has been reported. Should you want to perform multimodal analgesia with Ethiqa XR in mice, consult with an OAR veterinarian first.

More information about Ethiqa XR, including suppliers/distributors, can be found here: https://ethiqaxr.com/

Buprenorphine ER

Buprenorphine Extended-Release (Bup ER) is a patented compounded extended-release buprenorphine product provided by Wedgewood Pharmacy. Its former name was Buprenorphine Sustained Release (Bup SR).

Buprenorphine ER is a compounded controlled substance that can only be procured via prescription from a veterinarian. While prudent to keep it locked up for safety and security reasons, as a prescription drug, it is not required that you do so. If you do lock it up, do not store it in the same lock box as other DEA controlled drugs.

                                                                

Per FDA guidance GFI #256 Compounding Animal Drugs from Bulk Drug Substances, use of compounded drugs that have an FDA-approved equivalent must have a medical rationale describing the clinical difference between them.  This means there must be justification provided in order to procure Buprenorphine ER. For further prescriptions of Buprenorphine ER, a medical rationale will be required and reviewed by the prescribing veterinarian, who will make the final decision to write the prescription. 

All labs should review their use of Buprenorphine ER and consider obtaining the FDA-approved Ethiqa XR for future studies. 

 

Below is a chart comparing the two extended-release buprenorphine products:

Drug Information

Ethiqa XR

Buprenorphine ER/SR

FDA Approval Status

FDA-Approved

Compounded

 

Analgesia Length

Up to 72 hrs

48-72 hrs

Dosage

Mouse: 3.25 mg/kg SQ

Rat: 0.65 mg/kg SQ

Ferrets: 0.6 mg/kg SQ

Lab Rabbits: 0.15 mg/kg SQ

Mouse: 0.5-2 mg/kg SQ

Rat: 1-1.2 mg/kg SQ

Concentration

1.3 mg/mL

0.5, 1, and 3 mg/mL

Volume

3 mL

5 mL

Shelf Life Unopened

36 months

Varies by lot; typically 10-12 months from date of purchase

Shelf Life after Piercing Rubber Seal

90 days

30 days

Cost per vial*

$415

$150-190

How to Obtain

Investigators can purchase on their own with their individual DEA license through multiple suppliers/distributors 

https://ethiqaxr.com/ordering/

Lab submits ‘Buprenorphine-ER Prescription Request Form’ through OAR’s Drug Orders website. An OAR veterinarian will review and write the prescription. Drug ordered by lab through Wedgewood Pharmacy

 

 

 

Last Reviewed by the IACUC 4/8/2026