Addiction Medicine 1 Flashcards
(41 cards)
What is a substance use disorder?
A maladaptive pattern of substance use over the past 12 months that leads to impairment in social, physical or occupational functioning. It is characterized by
≥2 of 11 symptoms within a 12-month period
What is substance dependence?
A non-DSM term referring to the compulsive use of a substance despite negative consequences.
• Psychological dependence: Compulsive substance use without withdrawal and tolerance
• Physical dependence: Compulsive drug use with withdrawal and tolerance
What is intoxication?
The development of physical or psychological symptoms due to the recent ingestion of a substance and its CNS effects.
What is withdrawal?
The development of physical or psychological symptoms after the reduction or cessation of intake of a substance.
What is tolerance?
A need for increased amounts of substance to achieve the same physical and psychological effects.
What are the symptoms of substance use disorder?
What causes addiction?
Initial drug use is a conscious decision, voluntary→attributable to multiple biopsychosocial factors.
• Continued, compulsive use of drugs (i.e. addiction) is due to the effects of the drug on brain functioning.
What are the biopsychosocial factors of addiction?
Psychosocial: • Factors that make a drug’s reinforcing effect more potent • Age of first use • Method of administration • Presence of other mental illness • Coping strategy for emotions
- Genetics:
- Account for 40-60% of vulnerability
- What is inherited is unknown (e.g. less dopamine availability making someone more vulnerable to the rewarding effects of drugs)
Explain the stimulation of the reward pathway
- Stimulation of reward pathway
• Drugs of abuse stimulate the brain’s reward circuitry (directly or indirectly), signaling the person to repeat the behavior
- Overrides the more evolved cortical areas underlying reasoning and logic
- Activates the reward pathway with a force not seen with natural rewards (food, sex) and overrides punishing effects
Components of reward pathway:
• Neurons in the Ventral tegmental area (VTA) send their dopaminergic axons to nucleus accumbens, striatum & prefrontal cortex (structures involved in motivation)
• Nucleus accumbens (ventral striatum) – greater release of dopamine in the nucleus accumbens →mediates positive reinforcing effect of drugs
How does addiction impact the brain?
Dysfunction of the Prefrontal Cortex
• Stimulation of the reward pathway affects the functioning of the prefrontal cortex → alters self control
What are the acute withdrawal symptoms of addiction?
Acute Withdrawal Symptoms
• Drug use may cause brain changes that result in withdrawal symptoms upon drug cessation.
• Symptoms typically onset within 48-72 hours and last 1-2 weeks. This discomfort may drive relaps
What is protected abstinence syndrome?
Protracted Abstinence Syndrome
• Repeated drug use decreases the availability of DA as the brain adapts to having drug- induced dopaminergic spikes
• This is associated with prolonged feelings of anhedonia lasting several months, which may trigger relapse.
How does getting conditioned aid in addiction formation?
Classical Conditioning Effects
• Drug use has been paired with environment/internal cues
• These cues cause physiological changes that trigger drug seeking
Summary:
This is a “brain disease” that causes CNS changes that promote drug use
What are the main sedatives?
Alcohol
• Barbiturates
• Benzodiazepines
• Inhalants
What are the stimulants?
Major stimulants ➢Cocaine ➢Amphetamines ➢Ecstasy ➢Bath salts ➢Designer K2
• Minor stimulants
➢Caffeine
➢Nicotine
What are the common features of intoxication?
Common Features of Intoxication:
a) Sedation, sleepiness, decreased anxiety
b) Disinhibited, impaired judgement
c) Slurred speech, incoordination
d) Stupor, coma
e) Respiratory depression
f) Overdose can be potentially fatal
Other Potential Features of Intoxication:
a) Anticonvulsant & anesthetic effects (decrease neuronal firing)
b) Alcohol-related brain damage (ARBD) (e.g., Wernicke-Korsakoff syndrome due to thiamine (B1) deficiency in chronic alcoholics)
c) Cross tolerance to other sedatives
What are the types of sedative withdrawl symptoms?
• Common Features of Withdrawal:
a) Agitation, insomnia, anxiety
b) ANS hyperactivity → can be fatal
i. Tachycardia
ii. Hypertension
c) Nausea, vomiting
d) Hand tremors
e) Seizures
Hallucinations
a) Any sensory modality, including tactile
b) Formication – sensation of bugs crawling on skin
c) Can occur as the main symptoms of withdrawal without physical symptoms (e.g. in “alcohol hallucinosis”)
Delirium Tremens (DTs)
• A delirium (confusional state) may also occur as part of sedative withdrawal
• Severe and uncommon
• Seen after chronic heavy use of sedative especially alcohol
• Associated with high mortality rate
How to treat alcohol withdrawal?
Treatmentduringacutewithdrawal:
• Benzodiazepines→chlordiazepoxide, lorazepam, diazepam
• Effective in relieving the symptoms associated with withdrawal and preventing the DTs and seizures
- Treatment to maintain abstinence:
- Options:
- Competitive inhibitor of the actions of opioids
- Unknown mechanism of action
- Producing unpleasant side effects when alcohol is used
What treatment can be used to maintain alcohol abstinence ?
- Treatment to maintain abstinence:
- Options:
- Competitive inhibitor of the actions of opioids
- Unknown mechanism of action
- Producing unpleasant side effects when alcohol is used
Competitive inhibitor of the actions of opioids:
a) Naltrexone:
• Opioid receptor antagonist that reduces the pleasurable effects of alcohol
• Reducing the rewarding effects→may reduce the amount of heavy drinking in those who do drink (cutting down)
• Allows person to stop or reduce their drinking behaviors enough to remain motivated to stay in treatment and avoid relapse
Unknown mechanism of action: b) Acamprosate: • NMDA receptor antagonist?? Incompletely understood • Restore neuronal activity ?? • Decreases the anhedonia of protracted abstinence→makes the person feel euthymic→decreases the cravings & helps to maintain abstinence
Treatment to maintain abstinence:
• Producing unpleasant side effects when alcohol is used:
➢ Disulfiram:
• Inhibits aldehyde dehydrogenase→acetaldehyde accumulates and causes a
toxic reaction (e.g. nausea) for 30-60 min.
• An alcohol aversion agent
• Due to poor compliance, it is only used short-term if the person will be in a high risk situation.
• May not reduce a patient’s urge to drink alcohol
• However, their expectation of a possible severe reaction if they drink alcohol may increase their motivation to remain abstinent
What FDA approved drugs are used for sedative addiction?
FDA approved drugs for sedative addiction exist only for alcohol
What are the types of benzpates and barbiturates?
Types:
• Benzodiazepines (diazepam, lorazepam)
• Barbiturates (phenobarbital, secobarbital)
What are the benzodiazepine overdose/toxicity?
Treatment of Benzodiazepine overdose/toxicity • Flumazenil:
• Competitive antagonist
• High affinity for the benzodiazepine binding site on the GABAA receptor
- Approved for use in:
- Reversing the CNS depressant effects of benzodiazepine overdose
- Quickening recovery following use of benzodiazepines in anesthetic and diagnostic procedures
Describe inhalants of sedatives
Substances with psychoactive vapors (paint, glue, etc.)
• Teenager experimentation
• Signs: rash, red and runny nose, chemical smell, face discoloration
- Intoxication: similar to sedative intoxication
- Associated with organ failure & death (sudden sniffing death)
What are the common features of intoxication of stimulants?
Common Features of Intoxication: • Psychological: • Euphoria, grandiosity • Psychomotor acceleration & stereotypies • Paranoia, hallucinations
- Other features:
- Loss of appetite, insomnia
- Chest pains
- Seizure
- Dilated pupils (mydriasis)
- Tachycardia, hypertension (life threatening)
Sounds like mania
Sounds like psychosis
Common features of intoxication mimic symptoms of other illnesses:
1. Schizophrenia
2. Bipolar I (manic) episodes
Both disorders may be clinically indistinguishable from stimulant use A drug screen is needed
Mania +/- psychotic features
