Substance Abuse

Table Of Contents
1 Screening
2 Physical Exam
3 Treatment
3.1 Opioids
3.2 Tobacco
3.3 Alcohol
3.4 Stimulants
  • Substance abuse: Pattern of using leading to significant impairment and ongoing use in spite of poor consequences (legal, professional, relationships)
  • Substance dependence: Pattern of using leading to significant impairment or distress with drug tolerance, withdrawal, inability to cut down, and continued use despite problems
  • Reward pathways are mediated by dopamine, GABA, and some peptides
  • Stimulanant reward center: Ventral tegmentum, nucleus accumbens, frontal cortex
  • Opiate reward center: Periaqueductal gray, arcuate nucleus, amygdala, locos coeruleus
  • Genetics = 40-60% of vulnerability to addiction

Screening

  • USPSTF says insufficient evidence to assess whether adolescents, adults, and pregnant women should be screened for drug use.

Physical Exam

  • Dilated pupils → stimulants and hallucinogens, withdrawal from opioids
  • Constricted pupils → opioids

Treatment

  • Detox has 3 goals:
    • begin abstinence,
    • reduce withdrawal symptoms and complications,
    • and keep the patient in treatment
  • Pharmacotherapy:
    • Opioids
      • withdrawal is basically the flu = cramping, aches, anxiety, vomiting, malaise, goosebumps (cold turkey), runny nose, diarrhea, insomnia, elevated BP, and pulse
      • Methadone – long-acting synthetic opioid. Can cause euphoria and sedation
      • Buprenorphine – the partial agonist, lowers the risk of overdose, reduces/stops withdrawal symptoms. No euphoria and sedation.
      • Naltrexone – long-acting synthetic opioid antagonist. Prevents feeling positive feelings from a drug, reduce withdrawal
      • Naloxone – for acute intoxication treatment. Give nalOxOne at the Onset of Overdose
    • Tobacco
      • Varenicline – partial agonist/antagonist. Minimal stimulation of opioid receptors but not enough for dopamine release → reduces cravings. Not studied in combination with other smoking cessation agents.
      • Buproprion – blocks norepinephrine and dopamine reuptake
      • Nicotine replacement
    • Alcohol
      • – DTs in 48-72 hours. Naltrexone and acamprosate are most effective in combo with behavioral therapy.
      • Naltrexone – reduces relapse by up to 36% in the first 3 months but not very good for the long term.
      • Acamprosate – reduces withdrawal by acting on GABA and glutamate pathway. Good at maintaining abstinence in severe drinkers for several weeks to months
      • Topiramate – like acamprosate but not FDA approved for this use
      • Benzodiazepines (chlordiazepoxide, diazepam, lorazepam) – reduce the severity of withdrawal, reduce risk of seizures and DT
      • Disulfiram – retention of acetaldehyde → flushing, nausea, vomiting
      • Beta-blockers – as adjuncts to improve vital signs and reduce craving
      • Clonidine – alpha agonists, decrease withdrawal severity
    • Stimulants 
      • paranoia, depression, sleepiness, anxiety, irritability, difficulty concentrating, increased appetite, motor retardation
      • Propranolol – improves treatment retention, reduces cocaine use. Seems similar to the principle of naltrexone.
      • Desipramine, buproprion – antidepressant
      • Methylphenidate, amantadine – indirect dopamine agonists, improve treatment retention