Psych 3822 Chapter 8

Depressant

Drug that diminishes physiological activity (high abuse potential)

How do most depressants act?

Through increased activity of GABA

GABA A receptor

Ionotropic receptor that allows entry of Cl- ions

Barbiturates

Classified according to speed of onset and duration of action

Ultrashort-acting barbiturates

Produce effects within 10-20 seconds, maintains for about 30 minutes

Intermediate barbiturates

Takes effect in 30-60 minutes, provides sleep inducing effects for 3-6 hours

Long-acting barbiturates

An hour to take effect, producing effects for about 10-12 hours

Example of ultrashort-acting barbiturates

Thiopental

Example of intermediate acting barbiturates

Pentobarbital

Example of long-acting barbiturates

Phenobarbital

Effects of barbiturates on the Cerebral cortex

disinhibition, poor decision making, reduced attention and memory

Effects of barbiturates on the Amygdala

reductions in anxiety

Effects of barbiturates on the Medulla

respiratory depression

What is the main concern of barbiturate overdose?

Death from respiratory depression

What does barbiturate withdrawl lead to?

Barbiturate Abstinence Syndrome

Benzodiazepines

“minor tranquilizers”, most prescribed by general practioners

What was the first benzodiazepine to reach the market?

Chlordiazepoxide (Librium)

What do long-lasting benzodiazepines produce?

Active metabolites

Benzodiazepine site

Benzodiazepines serve as positive modulators by binding to an allosteric site

BZI site

High-affinity site, a1 subunit

BZII site

Low-affinity site, a2, a3, or a5 subunits

Endozepines

Substances produced by the brain that bind to benzodiazepine sites

Diazepam-binding inhibitor

neuropeptide with active fragments

B-carbolines

released from glial cells

Z drugs

Non benzodiazepines hypnotics which start with z, sleep aids

Gamma-Hydroxybutyrate (GHB)

Both a drug and neurotransmitter, dubbed “date rape"

Two drugs that produce GHB

GBL and 1,4 butanediol

Pharmacological effect onset of GHB

15-20 minutes

Inhalants

Vaporous chemicals with psychoactive effects

Amyl nitrite

“poppers", creates feelings of warmth and light headedness

Nitrous oxide

Laughing gas, euphorogenic

Volatile solvents

Mostly hydrocarbon chemicals

Age group that mostly uses inhalants

Children below grade 8

Sniffing

Direct inhalation of vapors

Huffing

Placing a soaked cloth over mouth and nose

Bagging

Placing compound in a small bag and inhaling

What can chronic use of inhalants lead to the loss of?

Brain tissue ( as well as ventricular enlargement and white matter degeneration)