Transcript Depressants. - Littleton High School

Depressants.
Overview
• Alcohol
• Barbiturates
• Benzodiazepines
How it works
• Depressants go into blood, and cross Blood
brain barrier and binds to GABA receptors
• GABA receptors signal dopamine receptors,
which releases dopamine into the brain (this is
what makes you feel “good” or “spacey” on
depressants)
Alcohol
• Stimulant from hormone secretionalcohol stimulates the adrenal glands
• Some alcohol is synthesized in stomach,
however, if enough is consumed it is:
• Absorbed through gastrointestinal tract,
however, must be oxidized (cannot be
stored)
• That happens in the liver
• Converted to acetaldehyde, to acetic
acid, to CO2 and water
• Produces an excess amount of NADH
• Ultimately, alcohol and all other
depressants inhibit the brain because of
their effect on GAVA receptors
Side effects-part 1
• Its that acetaldehyde, dude– Extra acetaldehyde goes into bloodstream, inhibits
mitochondria, which creates a vicious cycle  hepatitis
 death
• Extra NADH is bad– Excess synthesis of glycerol-makes people overweight
– Oversynthesize ATP  secrete lipids into the
bloodstream (to balance it out)  heart attacks (those
are bad)
• Physical dependence-addictions
Side effects-why drinking is bad
• Malnutrition-the alcohol that most
alcoholics drink in a day is enough to
provide 50% of energy requirementsdoesn’t contain nutrients (or those
carbohydrate, lipid, and essential
amino acid things we looked at)
• Hangovers-extra acetaldehyde causes
a hangover (headaches, nausea,
dizziness) because it builds up in the
body
Alcohol and the law
• Urine testing
– The least accurate-dependent on climate, metabolic
rate, and only accurate for 2 hours after drinking
– Tests for alcohol in liver
• Blood detection
– The MOST accurate
– Literally measures alcohol content from blood
• Breath detection (only used as proof for arrest)
– Oxidizes the alcohol in someone’s breath into acetic acid
– The electricity of the reaction is measured and used as a
method for determining the BAC
Legal Limits
• In Colorado
– DWAI (less severe penalties)-.5 to .8 BAC
– DUI (more severe)- more than .8 BAC
– If the subject has a BAC greater than .17, he/she is
subject to much more severe penalties and is
classified as a severely drunk driver
Benzodiazepines (aka Benzos)
• Most commonly used since 1960’s
• Used instead of barbiturates because they are
WAY safer
• How it works– Same as the general way
– Most benzos undergo oxidative metabolism
– All are then conjugated to glucoronic acid
– Drugs that DON’T undergo phase 1 metabolism
(oxidative) are safer for liver patients
http://pharmacy.wingate.edu/faculty/mnelson/PDF/Sedative_Hypnotics.pdf
http://pharmacy.wingate.edu/faculty/mnelson/PDF/Sedative_Hypnotics.pdf
Benzos-cont.
• Short acting, intermediate
acting, long term acting
determines use.
• Based on:
– Half life (how long for fifty percent
of drug to be eliminated)-longer
half life, longer duration
– Half life of active metabolite
(metabolic fate) the body, Benzos
become different benzos with
same effects (due to enzyme
reactions) [e.g. valium (diazepam)
is converted to serax (oxazepam)
in the body]
Barbiturates
• The first depressantswere used as sleeping
pills, anesthesia;
however, use
discontinued due to
side effects (death, with
high dose)
• Synthesized from
barbituric acid-aromatic
hydrocarbon structure
http://www.elmhurst.edu/~chm/vchembook
/6673barbit.html
Barbiturates-cont.
• The duration depends
on the number five
alkyls-longer chains,
shorter effect
• Based on the lipid
solubility (polarity) of
the molecule used
Barbiturates-cont. cont.
• At low doses, work regularly on the GABA
receptor
• High doses-antagonize GABA receptors, which
causes brain depression (that’s bad, literally
means a depression in brain activity)
Barbiturates-2cont.+cont.
• Used as anti-epileptic
medicine
• Used as an IV
anesthetic
• After head injuriesreduce swelling and
reduce glutamate
• Sedation in therapy
Barbiturates-22cont.-Side effects, OR,
why we no longer use Barbiturates
• THEY KILL YOU
• Lethal depression of breathing-easy to
overdose (often used in suicides)
• Triples birth defects
• Decreased REM when used as a sleeping pill
(because it is an anesthetic)
• Addiction
– Rapid tolerance development
– Life threatening withdrawal
Bibliography
• Alcohol Abuse and Dependence: Nutrition on the Rocks. Mary Anne
Clairmont, RD. Today’s Dietitian, September 2005
(http://cms.skidmore.edu/health/education/Alcohol_And_Drugs/al
cohol-and-nutrition.cfm)
• “Pharmacy 725: Sedative and Hypnotic Drugs”
http://pharmacy.wingate.edu/faculty/mnelson/PDF/Sedative_Hypn
otics.pdf
• Elmhurst College, Virtual Chembook “Barbiturate Drugs”
http://www.elmhurst.edu/~chm/vchembook/6673barbit.html
• Elmhurtst College, Virtual Chembook, “Alcohol Metabolism”
http://www.elmhurst.edu/~chm/vchembook/642alcoholmet.html
• Office of Legislative Legal Services “Colorado Drunk Driving Laws”
http://www.state.co.us/gov_dir/leg_dir/olls/PDF/COLORADO%20D
RUNK%20DRIVING%20LAWS.pdf
More bibliography
• Korschun., H. (2009). Antidepressant directly stimulates
brain growth factor receptors. Woodruff Health
Sciences Center, Retrieved from
http://whsc.emory.edu/home/news/releases/2009/06
/antidepressant-stimulates-brain-growth-factorreceptors.html
• Walker, E. (2009). Psychoactive drugs. Weber
University, Retrieved from
http://faculty.weber.edu/ewalker/Medicinal_Chemistry
/topics/Psycho/psycho.htm