<unk>  (INN, JAN), also known as alphaxalone or alphaxolone (BAN), is a neuroactive steroid and general anaesthetic. It is used in veterinary practice under the trade name Alfaxan, and is licensed for use in both dogs and cats.[citation needed] Along with alfadolone, it is also one of the constituents of anesthetic drug mixture althesin.
Unlike some of its predecessors<unk>  is not associated with histamine release and anaphylaxis.[citation needed]
A study 1987 found the primary mechanism for the anaesthetic action of<unk>  to be modulation of neuronal cell membrane chloride ion transport, induced by binding of<unk>  to GABAA cell surface receptors.

A 1994 study found that<unk>  binds to a different region of this receptor than the benzodiazepines.
. These benzodiazepine-insensitive GABAA receptors are located extrasynaptically and are responsible for tonic inhibition. The occurrence of tonic GABAA inhibition coincides with the expression of relatively rare receptor subunits, particularly the α4, α6, and δ subunits, and as a general rule-of-thumb, δ subunit-containing receptors are extrasynaptic.<unk>  is metabolised rapidly in the liver. It has a very short plasma elimination half-life in dogs and cats.[citation needed]
Alfaxalone
Metaxalone
Guaifenesin
Mephenoxalone
Cimetropium bromide
Butalbital
Rescinnamine
Nomifensine