Barbiturates and Benzodiazepines

Question 1

how does phenobarbital work

Answer 1

• discovered in 1911
• potent anticonvulsant effect at doses that are not sedative
• still used today to control generalized tonic-clonic and
  complex partial seizures, anxiolytic, hypnotic
• effect depends on dose

Question 2

how does pentobarbital work

Answer 2

• discovered in 1916
• potent anticonvulsant and sedative/hypnotic
• used today only for animal euthanasia

Question 3

what are their adverse effects:

Answer 3

• sedation
• physical dependence
• exacerbation of seizures upon withdrawal
• narrow therapeutic window (lethal overdose)

Question 4

what does Benzodiazepines consist of

Answer 4

fusion of a benzene ring and a diazepine ring

Question 5

what are Benzodiazepines effects

Answer 5

Benzodiazepines have a number of selective effects
- sedative
- hypnotic
- anxiolytic
- anticonvulsant

Question 6

what is the mechanism of benzodiazepine tolerance

Answer 6

subunit switch
- increased internalization
- altered phosphorylation
- uncoupling of the GABA /
benzodiazepine sites