Pentobarbital Sodium

Pentobarbital sodium is indicated for use as a general anesthetic in dogs and cats. Although it may be used as a general surgical anesthetic for horses, it is usually given at a lower dose to cause sedation and hypnosis and may be supplemented with a local anesthetic. It may also be used in dogs for the symptomatic treatment of strychnine poisoning. The drug is administered intravenously "to effect." It is one of the most potent anticonvulsants available and has the widest spectrum of activity.

The main action of pentobarbital sodium is to depress the central nervous system, and effects upon other systems of the body, only become important as the toxic limitations of the drug are approached. It depreses the cerebral cortex, and probably the hypothlamus. Because it also depresses motor centers of the brain it is used to control convulsive seizures. It has only a weak analgesic action and relatively large doses must be administered to cross the blood-brain barrier. The drug markedly depresses the respiratory center and in pregnant animals it penetrates the placenta into the fetal circulation, inhibiting fetal respiratory movements .

Primary Uses Ip injection of pentobarbital has been widely /used/ in small animals but now is limited primarily to those difficult to restrain for iv injections. ... Depression appears in about 15 min and persists in some measure /for/ 4-8 hr. IV injection of pentobarbital is the most satisfactory method of admin for /the/ production of anesthesia. An iv injection of a small dose of pentobarbital is used to produce hypnosis or sedation to avoid the fright, excitement, & resistance to restraint that are so dangerous and objectionable in handling. Pentobarbital is an important drug for relieving convulsive seizures, esp when caused by strychnine or other convulsants, for use as preoperative medication to help reduce anxiety and facilitate induction of anesthesia.

Pentobarbital Sodium is an active ingredient in the following proprietary animal drugs: Somnopentyl Injection, Combuthal Powder, Sodium Pentobarbital Injection, Beuthanasia-D Special, Euthasol, Euthanasia-III Solution. In acute barbiturate poisoning the respiration becomes shallow & slow & when intoxication is fully developed, there is extreme lethargy & coma, with disappearance of the reflexes; the pupils become dilated. Death occurs from respiratory failure, due to depression of the resp center. Large doses of the drug may be damaging to the liver.


  1. Hazardous Substances Data Bank
  2. FDA
  3. Veterinary Pharmacology and Therapeutics. H. Richard Adams
  4. Veterinary Anaesthesia. Leslie W. Hall, K. W. Clarke, Cynthia M. Trim