CPPS 306 Drug and Substance Abuse

What is drug abuse

Any use of a drug that does more than harm than good for the individual or for society

Define:

• Inappropriate use

• Inappropriate non-use

• Recreational or non-medical use of drugs

Inappropriate use = using a drug when you should

Inappropriate non-use = not using a drug when you hsoul d

Recreational / non medical use = using drugs without medical intent

What are the club drug classes and the drugs names

Depressants: GHB, Flunitrazepam

Dissociative: Ketamine, PCP

Stimulant/hallucinogens MDMA

Adictive potential of a dug

Addictive drugs have pleasant direct effects and short half-lives

What are the natural stimulant recreational drugs

Nicotine

Caffeine

Cocaine

Ephedrine (in stimulant lecture)

What are the synthetic stimulant recreational drugs

Amphetamine and its relatives (methylphenidate)

What are the natural depressant recreational drugs

Marijuana

Opium

Ethanol

What the the synthetic depressant recreational drugs

Barbiturates

Opioids (heroin)

Benzodiazepines

What is the mechanism of THC

THC receptors linked to Gi protein → decrease cAMP which reduces activity in NE, DA, Glu, and other pathways

Whare the the two ENDOGENOUS endocannabinoids

Arachidonylethanolamide

2-arachidonylglycerol (2-AG)

How does the combinaiton of a stimulant with a depressent affect the “high”

Combination of a stimulant and a depressant MAKES THE HIGH BETTER

• Potentiates the high

What are hallucinogens

Hallucinogens alter or distort perception

What are the natural hallucinogens

Ergotamines = fungus growing on rye grain

Mescaline = peyote cactus

Psilocin = shrooms

Atropine and scopolamine

What ae the synthetic hallucinogens

• LSD

• PCP

• Benztropine (ANTI CHOLINERGIC THERAPY)

• Amphetamine

  • TMA

  • MDA

  • MDMA

How do opioids affect the reward pathway

Opioids activate the mu receptors on GABA interneurons in the VTA and decreases the activity of GABA inhibition which act on dopamine neurons

Less inhibition in dopamine neurons leads to more release of dopamine in the nucleus accumbens and enhances the reward pathway.

What are the mechanisms of action of hallucinogens

• increase neural activity in NE, DA, and 5-HT

• Reduce Ach pathway activity

How does cross tolerance develop with hallucinogens

Cross tolerance develops to drugs sharing the same mechanism of action, but not across mechanisms

What drugs are used to treat opioid abuse

• Methadone (narcotic analgesic)

• Naloxone / naltrexone = opioid ataganoist

Specifically, which drug is used for opioid dependency

Methadone

• Good oral absorption, less euphoria

• Long half life

What drugs are used to treat nicotine abuse

• Nicotine replacement therapy

• Varenicline

• Buproprion (atypical antidepressant)

Is alcohol a depressant or a stimulant

Depressant

Explain the metabolism of ethanol

Ethanol —ADH→Acetaldehyde —ALDH→ Acetic Acid

What receptors do ethanol act on

• GABA

• NMDA

• 5HT

What are mechanism of action of ethanool

• Reinforcing action through reward pathway

• Supresses neuronal excitability in a concentration dependent manner

• Limbic nerons are more sensitive than neurons in other parts of the brain

What drigs are used to treat alcohol dependence

Disulfiram = inhibits ALDH

Acamprosate = Glutamte receptor antagonist

Naltrexone = opioid receptor anatagonist with good oral absorption

Naloxone = opioid receptor antagonist with poor oral absorption

Explain the metabolism of methanol

Formaldehyde and Formic Acid = toxic

What is the treatment for methanol toxicity

Mix ADH with ethanol

• Give bicarbonate to reduce acidosis

• initiate hemodialysis

• Formepizole

What is Fomepizole

An ADH inhibitor used for treating methanol poisoning

Explain the metabolism of ethylene glycol

These metabolites are very toxic!!!!!

What happens with ethylene glycol metabolites

They are toxic and severe metabolic acidosis develops 4-12 hours in

What are the treatmenrts of ethylene glycol

• Ethanol

• Fomepizole

• Bicarbonate

• Dialysis

Then add fluids and calcium