Drugs of Abuse Flashcards
Substance Abuse Disorder
What are the 3 critical components?
Abuse
Craving
Legal problems
What are the criteria of Substance Abuse Disorder?
- Tolerance
- Withdrawal
- Using larger amounts than intended
- Persistent desire and inability to control use
- Excess time spent
- Normal activities reduced or given up
- Unable to cut back
Mild 2-3
Moderate 4-5
Severe >5
What is tolerance?
Decreased effect with repeated use of the drug
Need to use more drug to have the same effect
What is withdrawal?
Signs and symptoms that emerge when use of drug is stopped
Symptoms subside when drug is administered again
What is the major neuronal circuit involved in drug abuse? Where does it project to?
Mesolimbic dopamine system in the VTA, projecting to the nucleus accumbens, amygdala, and prefrontal cortex
What are two mechanisms (generally) by which you can produce withdrawal syndrome?
Stop taking the drug
Give an antagonist to the drug
Cocaine
MOA
Inhibits dopamine transporter on the presynaptic membrane, preventing reuptake of dopamine
Levels of dopamine in the synaptic cleft increase, mostly in nucleus accumbens
Amphetamines
MOA
Inhibits VMAT2, preventing dopamine from being packaged into vesicles in the axon terminal
Dopamine levels increase in the cytoplasm and eventually the dopamine reuptake transporter will reverse its transport of DA from inside –> outside cell into the synapse
What are the acute effects of Psychostimulants (Cocaine, Amphetamines)?
Rush High confidence Decreased fatigue and boredom Decreased appetite Increased HR, BP, temp
Cocaine
Half life
40-80 minutes
Cocaine
Metabolism
Metabolized in liver into an inactive compound, which can be detected in urine, saliva, hair, and milk for 8 days after use
What happens if you take cocaine with alcohol?
Cocaine will be transesterified, leading to cocaethylene
Cocaethylene causes more euphoria, but a higher cardiotoxic risk
Long Term Consequences of Cocaine/Amphetamine use
Sensitization or Tolerance
Impaired neurocognitive functions
Increased risk of autoimmune diseases
Signs of Cocaine Overdose
Hyperactivity Sweating Dilated pupils Agitation Tremor Tachycardia Chest pain Cardiac arrhythmia (deadly) HTN Seizures/coma Paranoia
Signs of Cocaine Withdrawal
Anxiety and agitation Insomnia or Hypersomnia Fatigue Sweating Muscle cramp Hunger ED
How should Acute Cocaine Withdrawal be treated?
Bromocriptine (dopamine agonist)
Benzodiazepines
How should long term addiction to cocaine be treated?
Cognitive Behavioral Therapy
List the Opioid Drugs of abuse
Morphine
Codeine
Heroin
Oxycodone
Opioids
MOA
Inhibit GABAergic neurons by blocking mew receptors
Since GABA normally inhibits release of dopamine, opioids increase the release of dopamine in the nucleus accumbens
Signs of Opioid Overdose
Unconsciousness Miosis Hypotension Bradycardia Respiratory Depression Pulmonary edema
Describe the metabolism of heroin
Heroin is a prodrug that is converted to 6-monoacetylmorphine by esterases, which is then metabolized to morphine, which contributes to heroin’s duration of effect
Opioid Withdrawal Symptoms
Lacrimation Rhinorrhea Yawning Piloerecetion/gooseflesh Involuntary movement Anxiety Craving Sleep disturbance Nausea, vomit, diarrhea Sweat Mydriasis Cramps