Policy Number: 2012-046-v
Policy Title: Use of Tribromoethanol (Avertin)

POLICY: Tribromoethanol (TBE; also referred to as Avertin) is an injectable anesthetic historically used in laboratory mice. Other anesthetics, both injectable and inhalant, have largely replaced TBE. In addition, TBE is not available as a pharmaceutical-grade product, and its use is not considered by federal regulatory veterinary authorities to reflect current standards of veterinary care. View statements from OLAW and USDA's "Use of Non-Pharmaceutical-Grade Chemicals and Other Substances in Research with Animals - March 1, 2012” at http://grants.nih.gov/grants/olaw/educational_resources.htm

Use of TBE, therefore, must be described and scientifically justified in an animal care and use protocol. The Institutional Animal Care and Use Committee must critically evaluate and approve the use of TBE. Cost savings and convenience (e.g., avoidance of DEA controlled substances) are not considered appropriate justifications for the use of TBE. The following two scenarios may be instances where the use of TBE could be justified and approved; other applications may be approved if sufficient scientific justification is presented:

  1. A long-term ongoing study where a significant amount of data has been collected with the use of TBE, or a study where new data must be compared with historic data collected using TBE; TBE use may then be continued until the end of these studies.
  2. An investigator is specifically studying the effects of TBE.

Because there is no pharmaceutical-grade formulation of TBE available, it must be compounded by laboratories. Tribromoethanol must be prepared, stored, and used as follows:

  • TBE is for use in mice only.
  • Filter-sterilize with a 0.2 micron filter; store and use under sterile conditions.
  • Store in a dark or foil-covered bottle to prevent breakdown by light.
  • Store stock and working stock solutions at 4°C.
  • Do not use if solution is discolored or precipitates.
  • Check pH before each use, and use only when pH is greater than 5.0.
  • Discard ALL solutions after 4 months, including stock solution.
  • Label all containers with the name and concentration of drug, date prepared, and initials of the person making the solution.
  • Tribromoethanol can be used ONLY one time in any individual animal for survival procedures.

Failure to follow these instructions may reduce the potency and efficacy of the drug, and/or result in tissue necrosis at the injection site, peritonitis, or other adverse events.

Author: D. Jefcoat, J. Welter
ePublication Date: 05/25/2012