Drugs and Behavior Exam 2

Psychostimulants

Speeds everything up: Cocaine, Methamphetamine, Amphetamine

Opioids

Pain relief + high addiction + slows breathing: Fentanyl, Heroin, Morphine, Oxycodone

Psychedelics

Sees things + changes perception and thinking: LSD

Cannabinoids

Weed, mixed (mild depressant + hallucinogen): Marijuana

Depressants

Slows the nervous system: Alcohol

Nicotine

Strong dependence: Cigarettes and Vapes

Xanthines

Mild, everyday: Caffeine

Psychotherapeutics

Medical use to regulate brain function: Anti-depressants + Ant-anxiety meds

Drug Classes

1. Psycostimulants

2. Opioids

3. Psychedelics

4. Cannabinoids

5. Depressants

6. Nicotine

7. Xanthines

8. Psychotherapeutics

Specific Effects

Pharmacological or chemical effects of dryg on brain/body

Nonspecific Effects

Effects not due to drugs pharmacological actions on the brain/body

• “Set and Setting” important

• Placebo effects are non-specific effects (generally “good” non-specific”

• Nocebo effects are non-specific effects (generally “bad non-specific (side effects))

Some researchers say 80% of antidepressant effect is non-specific

• Placebo effect (expecting to feel better → actually feeling better)

• Doesn’t mean they don’t work, a specific drug may be smaller than people think

Balanced Placebo Design

A study that separates what you’re told from what you actually get.

ED50

Dose where 50% of people show the desired effect

LD50

Dose where 50% of subjects die

Therapeutic Index

Measure of drug safety (TI = LD50 / ED50)

High Therapeutic Index

Safer (Bigger gap between effective and lethal dose)

Low Therapeutic Index

Dangerous (Small gap)

How does tolerance shift the dose-response curve?

To the right, meaning higher doses are needed for the same effect.

Potency

Amount of drug required to produce an effect.

• Very potent drug = smaller dose

• Weak potency = big dose needed

Effectiveness (Efficacy)

Maximun effect a drug can have at any dose.

3 parts to the movement of drugs

1. Absorption (how to get the drug into the blood)

2. Distribution (of the drug around the body)

3. Elimination (or metabolism)

Drugs need to be lipid soluble (fat soluable) to:

• Enter the bloodstream

• Cross into the brain (blood-brain barrier)

Brain is protected → only lipid soluble drugs get in easily

Routes of Administration

• Oral

• Injection

• Inhalation

• Through skin or membranes

  • Intranasal

  • Transdermal

Oral Administration

Pros: Easiest and safest

Cons: Slow onset and first-pass metabolism

Injection

Pros: Fast, efficient, high subjective experience

Cons: Can be to fast, too efficient, most dangerous

Fast form of administartion

Inhalation

• 6-8s from inhale to brain

How are drugs metabolized?

1. Drugs start as fat-soluble (lipid-soluble)

2. Liver turns them into water-soluble

3. Kidneys remove them in urine

Fat-soluble

Stays in the body

Water-soluble

Leaves the body

Half Life

Time needed for ½ of the amount of drug in the body to be eliminated.

Tolerance

More of a drug to get the same effect over time.

3 Mechanisms by which tolerance occurs

1. Drug Disposition (Body): The body breaks down the drug faster. Due to more liver enzymes. Less of the drug reaches the brain.

2. Behavioral Tolerance (Behavioral): You learn to function while on the drug.

3. Pharmacodynamic (Brain): Brain/Neurons adapt to the drug. Has less effect on receptors. Opponent process: body pushes back.

Psychostimulants

1. Cocaine

2. Amphetamine

3. Cathinone

Cocaine was most popular in the:

Mid to late 1980s: Crack epidemic

What schedule is cocaine?

Schedule 2

Fair Sentencing Act

Reduced the sentencing gap between crack and powder cocaine from 100:1 to 18:1.

Forms of Cocaine

• Leaf

• Coca paste

• Cocaine hydrochloride (salt)

  • Cannot be smoked

• Free-base

• Crack

  • Can be smoked

Coca paste

Leaf soaked + mashed together with Kerosene/gasoline plus over chemicals

Free-base cocaine

Smokable, but super dangerous (ether needed)

Crack

Baking Soda + Cocaine Hydrochloride + Water + Heat

Routes of Administration of Cocaine

• Oral: Drink coca tea, cocaine elixirs

• Buccal/transmucosal: Chew leaves “gummer” (powder)

• Insufflation (snorting): Cocaine hydrochloride (powder)

• Inhalation: Freebase cocaine or crack

• Intravenous Injection: Cocaine hydrochlordie in saline/water

Cocaine is lipid-soluble.

Meaning it crosses the blood brain barrier.

Cocaine’s half life

Approximately 1 hour.

Pharmacodynamics of Cocaine

Blocks the reuptake of serotonin (5-HT) and norepinephrine (NE). Dopamine transporter is blocked by cocaine.

How addictive is cocaine?

About 20% of people who ever used cocaine go on to meet DSM criteria most closely corresponding to “addiction”

Acute toxic effects with high doses of cocaine

• Sudden death is possible due to

  • Cardiovascular events

  • Seizures

  • Respiratory arrest (stops breathing)

Chronic toxic effects of cocaine

• Cardiovascular system toxicity

• “Cocaine Psychosis” (May be a combination of acute and chronic effects)

  • Paranoid delusions

  • Auditory hallunication

  • Other psychotic symptoms

Crack Babies

Babies that are exposed to cocaine in the womb.

• People believed they would have permanent, devastating effects

• What we know now: Effects are usually subtle. Outcomes depend a lot on the environment.

Methamphetamine compared to Amphetamine

Methamphetamine is a stronger, longer-lasting version of Amphetamine, and reaches the brain faster.

Peak use of Methamphetamine

1990s and 2000s

Opium Wars

Britian forcing China to allow the opium trade and open its market.

3 factors contributing to the original US opioid epidemic (1890s)

1. Medical use - doctors prescribing morphine

2. Patent medicines - over-the-counter products with hidden opioids

3. Opium smoking - recreational use (often in opium dens)

Fifth Vital Sign

Pain

Natural opiates in the opium poppy

Morphine and Codeine

Peak prescription opioid use

2010s

% used heroin (past year)

0.3% est.

Semisynthetic opioids

Heroin, Hydromorphone, Oxycodone, Etorphine

Endogenous opioids

Natural opioids made by the body. (Endorphins, Enkephalins)

Potency (Most to Least)

Fentanyl > Heroin > Morphine > Codeine

Opioids route of administration

Basically, every route has been used.

• Oral

• Intravenous

• Intramuscular injection

• Subcutaneous (Skin Popping)

• Snorting

• Inhalation

• Transdermal (patches)

Half life of Morphine

2 hours

Half life of Methadone

10-24 hours

Half life of Buprenorphine

36 hours

Half life of Oxycodone and Fentanyl

3-4 hours

Subtype of the opioid receptor morphine has the most of its effect on

Mu

Agonist

Fully activates (Heroin, Morphine)

Antagonist

Blocks (Naloxone)

Partial Agonist

Activates weakly (Buprenorphine)

Naloxone

Reverse overdose. Brand: Narcan

Cross Tolerance

Tolerance to one opioid → tolerance to others

Cross Dependence

Dependence on one → withdrawal relived by another

Precipitated Withdrawal

Happens when antagonist displaces opioid → rapid withdrawal

Toxic effects of opioids

Respiratory depression (slowed or stopped breathing), leads to sedation, coma, death

Tranq Dope

Fentanyl mixed with Xylazine

Xylazine

Veterinary tranquilizer (not an opioid)

Xylazine is used to

Cause heavy sedation and longer high