| Toxicity: |
A barbiturate that
causes CNS depression, apparently due to a facilitation of
GABA-ergic inhibition. It appears that the site of action of pentobarbital may be the macromolecular complex made up of a
GABA receptor, chloride channel, benzodiazepine-binding site,
and picrotoxin-binding site. Barbiturates have been shown to
compete for dihydropicrotoxinin-binding sites. In clinical use,
barbiturates such as pentobarbital have been largely replaced
as sedative-hypnotics by the much safer benzodiazepines. The
sedative-hypnotic properties of barbiturates may lead to abuse, as
tolerance and dependence are known to occur. In animals, pentobarbital is routinely used for its anesthetic and anticonvulsant
properties, as well as for euthanasia. Pentobarbital, like other
barbiturates, can induce the metabolism of other compounds by
altering cytochrome P450 activity. The oral LD50 in rats is
118 mg/kg. |