Addiction and Drug Abuse

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Addiction and Drug Abuse

• By
• S.Bohlooli, PhD

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Cultural Consideration

• Licit or Illicit ?!
• Resultant criminal activity leads to make an
  agent considered as illicit.
• Activity like robbery, prostitution and other
  antisocial activity.

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• Drug Misuse
• A drug might be used for a wrong indication, or
  wrong dosage, and or too long period
• Drug Abuse
• abuse might be construed as any use of drug for
  non medical purpose

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substance dependence (addiction)

• cluster of symptoms indicating that the
  individual continues use of the substance despite
  significant substance-related problems.

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PHYSICAL AND PSYCHOLOGICAL DEPENDENCE

• Physical dependence is a state that develops as
  a result of the adaptation (tolerance) produced
  by a resetting of homeostatic mechanisms in
  response to repeated drug use.
• Psychological dependence is manifested by
  compulsive drug seeking behavior in which the
  individual uses the drug repetitively for
  personal satisfaction often in the face of known
  risks to health

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• Tolerance is the most common response to
  repetitive use of the same drug and can be
  defined as the reduction in response to the drug
  after repeated administrations

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Types of Tolerance
Innate (preexisting sensitivity or insensitivity)
Acquired
Pharmacokinetic (dispositional or metabolic)
Pharmacodynamic
Learned tolerance
Behavioral
Conditioned
Acute tolerance
Reverse tolerance (sensitization)
Cross-tolerance
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Origins of Substance Dependence

• Agent (drug)
• Host (user)
• Environment

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Agent (drug)

• Availability
• Cost
• Purity/potency
• Mode of administration
• Chewing (absorption via oral mucous membranes)
• Gastrointestinal
• Intranasal
• Subcutaneous and intramuscular
• Intravenous
• Inhalation
• Speed of onset and termination of effects
• Pharmacokinetics combination of agent and host

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Host (user)

• Heredity
• Innate tolerance
• Speed of developing acquired tolerance
• Likelihood of experiencing intoxication as
  pleasure
• Psychiatric symptoms
• Prior experiences/expectations
• Propensity for risk-taking behavior

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Environment

• Social setting
• Community attitudes
• Peer influence, role models
• Availability of other reinforcers (sources of
  pleasure or recreation)
• Employment or educational opportunities

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Withdrawal Syndrome

• Withdrawal signs and symptoms occur when drug
  administration in a physically dependent person
  is abruptly terminated.
• Withdrawal symptoms have at least two origins
• (1) removal of the drug of dependence,
• (2) central nervous system hyperarousal due to
  readaptation to the absence of the drug of
  dependence.

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VII. Co-administration/Co-abuse

• Many of these drugs are used in combination with
  other drugs from one or more categories.
• Alcohol is used, for example, with almost
  everything else.
• Smoking (nicotine intake) is prevalent in
  patients using other drugs.
• Be aware of the possibility of combination of
  drugs when treating intoxication, withdrawal or
  overdose, each drug will require a specific
  treatment.

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Neurobiology of Abused Drugs

• Many drugs acts through G protein coupled
  receptor (dopamine, opioid and cannabinoid)
• Chloride Ion channel associated with GABA
  (benzodiazepines)
• Excitatory amino acid receptors (phencyclidine)

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I. Animal Studies

• Drug-self administration
• Drugs as reinforcers in animals.
• High correlation with
• human dependence
• liability.

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Morphine/Heroin

• Self-Administration

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II. Brain Reward System

• Changes in brain function gt Rewardgt Craving
• Involve the Dopaminergic System
• Mesolimbic pathwayVentral tegmental area (VTA),
  medial forebrain bundle, nucleus accumbens and
  the prefrontal cortex.
• Nigrostriatal pathway Sustantia nigra, striatum.
• Mesocortical pathway VTA, cingulate and frontal
  CTX.
• Tubero-Infundibular Arcuate N. in hypothalamus.

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THE DOPAMINERGIC SYSTEM
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THE MESOLIMBIC DOPAMINERGIC REWARD PATHWAY
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Tyrosine
Dopamine Synapse
Tyrosine
L-DOPA
DA
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Dopamine Reuptake System
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Alcohol consumption

• Sedation
• Relief of anxiety
• Slurred speech
• Ataxia
• Impaired judgment
• Disinhebited behavior

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Alcohol Withdrawal Syndrome Alcohol Withdrawal Syndrome
Alcohol craving Confusion
Tremor, irritability Visual hallucinations
Nausea Fever, profuse sweating
Sleep disturbance Tachycardia
Tachycardia Nausea, diarrhea
Hypertension Dilated pupils
Sweating Severe agitation
Perceptual distortion
Seizures (12 to 48 hours after last drink)
Delirium tremens (rare in uncomplicated withdrawal)
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Benzodiazepine Withdrawal Symptoms
Following moderate dose usage
Anxiety, agitation
Increased sensitivity to light and sound
Paresthesias, strange sensations
Muscle cramps
Myoclonic jerks
Sleep disturbance
Dizziness
Following high-dose usage
Seizures
Delirium
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Nicotine Withdrawal Syndrome
Irritability, impatience, hostility
Anxiety
Dysphoric or depressed mood
Difficulty concentrating
Restlessness
Decreased heart rate
Increased appetite or weight gain
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Clinical aspect of opioid use

• Rush an orgasm like reaction
• Euphoria
• Feeling of tranquility and sleepiness

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Opioid Withdrawal Opioid Withdrawal Opioid Withdrawal
SYMPTOMS SIGNS  
Regular Withdrawal  
Craving for opioids Pupillary dilation  
Restlessness, irritability Sweating  
Increased sensitivity to pain Piloerection ("gooseflesh")  
Nausea, cramps Tachycardia  
Muscle aches Vomiting, diarrhea  
Dysphoric mood Increased blood pressure  
Insomnia, anxiety Yawning  
Fever  
Protracted Withdrawal  
Anxiety Insomnia Drug craving Cyclic changes in weight, pupil size, respiratory center sensitivity  
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CNS stimulants
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Clinical aspects of stimulants

• Rush
• Mental alertness
• Marked euphoria
• Delusion (bugs are crawling under skin!)
• Spree use ( up to 4000 mg /day amphetamine)
• Lack of food
• Lack of sleep

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Cocaine Withdrawal Symptoms and Signs
Dysphoria, depression
Sleepiness, fatigue
Cocaine craving
Bradycardia
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Clinical effect of marijuana

• Being high
• Euphoria
• Uncontrollable laughter
• Alteration of time sense
• Depersonalization
• Sharpened vision
• Late becoming relaxed, experience of
  introspective and dream-like effect
• Difficulty in concentration and thinking

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Marijuana Withdrawal Syndrome
Restlessness
Irritability
Mild agitation
Insomnia
Sleep EEG disturbance
Nausea, cramping
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Drugs Kill the Brain