"Animal drug" for executing animalistic humans

The ABC reports on a change of drugs for U.S. lethal injections:

A United States judge has approved a drug normally used to euthanise animals for use in capital punishment in Oklahoma.

The drug, pentobarbital, is indeed used to euthanise animals but has other uses:

Pentobarbital has also been used for physician-assisted suicide. It is used in the US state of Oregon for this purpose, and is also used by the Swiss euthanasia group Dignitas. Pentobarbital was also used for this purpose in the Northern Territory of Australia, prior to euthanasia becoming illegal in that region.

In the Netherlands, a pentobarbital elixir is used for physician-assisted suicide (an alternative to euthanasia for patients who wish to take the barbiturate needed for the lethal cocktail themselves, instead of having it administered intravenously, in which case thiopental is used). Pentobarbital has no current therapeutic use in the Netherlands, and is only used for this purpose.

Typically, when orally ingested for euthanasia purposes, an antiemetic drug is swallowed approximately 30 minutes before the lethal overdose of pentobarbital. This is done because large concentrated doses of pentobarbital may cause vomiting.

In this role, pentobarbital is highly sought after by people wishing to end their lives but not allowed to do so under their country's laws. It is therefore often smuggled across borders from countries where it is still available over-the-counter such as Mexico, or purchased through illegal mail orders.

Pentobarbital is used by those promoting and seeking a painless exit, so it is also suitable for executing those deemed to be deserving of elimination.