Drugs Of Abuse

Front 1

Abused drug classes

Back 1

-Narcotics (heroin)
-Stimulants (nicotine, cocaine, amphetamines)
-Psychedelics (LSD, PCP)
-Depressants (cannabis, GHB)

Front 2

Brain pathways involved in substance abuse

Back 2

All psychoactive drugs stimulate the brain's reward system

Mesocorticolimbic pathway
-DA neurons from VTA (midbrain) to NA and prefrontal cortex

Front 3

Tolerance
-definition
-mechanisms (2)

Back 3

w/ chronic/repeated use - larger dose required to achieve same response (same dose yields smaller response)

Common response to chronic use of most drugs - does NOT mean dependence or addiction
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Cellular/tissue tolerance (adaptation of response)
-inhibiting coupling to intracellular signaling
-receptor downregulation
-inhibit new receptor synthesis
-altered expression of signaling proteins

Metabolic tolerance
-enhanced elimination rate of drug

Front 4

Dependence
-physical
-psychological

Back 4

Physical dependence = withdrawal symptoms when drug is stopped
-occurs w/ many drugs (including those not abused) --> NOT ALWAYS indicative of abuse
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Psychological dependence = addiction
-behavioral syndrome - compulsive drug-seeking behavior
-occurs w/ drugs that activate reward system
-drug use dominates life/normal functioning and continues despite medical, legal, social consequences

Front 5

Ampetamines and cocaine (stimulants)
-MOA
-effects

Back 5

Amphetamines - enhance synaptic DA and NE release

Cocaine blocks DA re-uptake

DA = basis of addiction
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CNS - used to relieve fatigue --> arousal, insomnia, alertness, euphoria, increased temperature, talkativeness
-Peripheral - sympathomimetic, teeth grinding

Front 6

Amphetamines and cocaine
-what's the difference
-methamphetamine v. amphetamine

Stimulant overdose - effects

Chronic stimulant use - effects

Back 6

Minor differences; very similar response if same route of administration

Methamphetamine - slightly more CNS effects, less peripheral effects, longer-lasting
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Overdose - arrhythmia, MI, cerebral vasoconstriction (stroke)

Chronic use - continued wakefulness, anorexia, psychosis

Front 7

Amphetamines and cocaine
-tolerance
-dependence

Crack v. cocaine

Back 7

Rapid tolerance to euphoric effects and sensitization to other effects

Psychological dependence can be profound, difficult to treat
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Cocaine is readily soluble --> can be snorted/injected

Free base (remove hydrochloride) --> crack (not soluble) --> must be smoked --> rapid entry into brain --> rush --> increased abuse

Front 8

Nicotine
-effects
-pharmacokinetics
-therapeutic potential

Back 8

#1 source of preventable disease

Both calming and stimulant (arousal, concentration, loss of appetite) effects

Smoking --> nicotine gets to brain very rapidly --> rush/pleasurable feeling --> reinforcing --> addictive potential

Therapeutic potential
-smoking cessation
-Parkinson's, Alzheimer's, Tourette's

Front 9

Depressants
-alcohol
-barbiturates
-benzodiazepines
-cannabis

Back 9

Alcohol and barbiturate withdrawal can be LETHAL
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BZs - abuse mostly w/ fast-acting
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active ingredient - THC (very lipid soluble)

smoked/eaten - slower/long effects w/ oral use

little physical dependence, modest psychological dependence

Front 10

Psychedelics
-effects

Back 10

Sympathomimetic, altered perception, hallucinations, altered mood/thought process
-effects highly dependent on set (expectations) and setting (environment)

Front 11

Deliriants
-PCP, ketamine

Back 11

anesthetics - inhibit NMDA glutamate receptor

sympathomimetic, parasympathomimetic, muscle rigidity, ataxia, increased strength

Violent/bizarre behavior

Psychosis, mood/personality disorders

Front 12

Salvia

Back 12

salvinorin A (active ingredient)

agonist at kappa opioid receptors (dysphoria, psychosis)

brief duration (10 min)

Front 13

Inhalants
-effects

Back 13

exhilaration, euphoria, drunkenness, hallucinations

Front 14

Performance enhancers
-anabolic steroids
-GHB

Back 14

increased confidence/motivation, decreased fatigue, agitation, irritability, insomnia, aggression/violence (chronic use)
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increases muscle, decreases fat by growth hormone release
-prolonged euphoria, sedation

Front 15

TX of Substance Abuse

Back 15

tolerance is reversible

drug addiction persists for years/lifetime and cravings persist long after drug stopped

TX based on chronic disease model

Counseling is very important

Front 16

TX of opioid dependence and withdrawal
-methadone
-kinetic differences from heroin
-methadone detox

Back 16

Withdrawal
-re-administer drug (another opioid w/ more favorable properties - METHADONE)

IV heroin - rapid oscillation of high and sickness

Oral methadone - more stable kinetics; allows for functional/productive living

Methadone maintenance
-goal is to switch from heroin to methadone dependence (less toxic addiction)

Methadone detox
-Once dependence is switched to methadone, easier to withdraw

Front 17

Drugs for treating opioid addiction
-Methadone
-LAAM
-Buprenorphine
-Naltrexone

Back 17

Methadone
-used for maintenance and detox

LAAM
-very long-acting version of methadone

Buprenorphine
-partial agonist at mu receptor
-difficult to overdose

Naltrexone
-long-acting oral mu antagonist
-useful for alcoholism

Front 18

Varenicline

Bupropion

Back 18

Varenicline - partial agonist at a4b2 CNS nicotinic receptor
-black box warning (suicide, depression)
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Bupropion
-anti-depressant
-can complement results of nicotine replacement therapy (NRT)