USMLE

Benzodiazepines

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Mental Health Drugs
  1. Tricyclic Antidepressants
  2. SSRIs
  3. SNRIs
  4. Benzodiazepines
  5. Barbiturates
  6. Typical Antipsychotics
  7. Atypical Antipsychotics
  8. Lithium
  9. MAOIs
  10. Bupropion
  11. Buspirone
  12. Trazodone
  13. Zolpidem
  14. Amphetamines

Summary

Benzodiazepines, or benzos for short, are a large class of drugs with drug names that end in -pam, like clonazepam and lorazepam, names that end in -lam, like midazolam and alprazolam, as well as chlordiazepoxide. Benzodiazepines are central nervous system depressants, meaning they slow the brain down and reduce brain activity. This is helpful in treating anxiety, treating seizures, as well as treating the symptoms of alcohol withdrawal. Benzodiazepines cause sedation, to the point where some benzodiazepines may even be used to treat insomnia. Benzodiazepines can also cause respiratory depression, if taken in excess or if taken with other CNS depressants like alcohol or opioids. Benzodiazepines can cause tolerance and dependence, and if possible, the drug should be tapered down slowly to avoid withdrawal symptoms. If respiratory depression or other toxic effects of benzodiazepines do occur, flumazenil is the antidote used and can reverse the effects of benzodiazepines.

Key Points

  • Key drugs
    • -pam Ending
      • Clonazepam
      • Lorazepam
      • Diazepam
    • -lam Ending
      • Midazolam
      • Alprazolam
    • Chlordiazepoxide
    • Clorazepate
    • Mechanism
      • CNS Depressant / Anxiolytic
        • Potentiates the effects of GABA to depress the CNS
        • Stabilizes neuronal membranes and suppresses the the spread of seizure activity
        • Acts on limbic, thalamic, and hypothalamic levels of the CNS (Suanders)
    • Clinical Use
      • Anxiety Disorders
        • Generalized Anxiety Disorder
        • Panic disorder
        • Post-traumatic stress disorder (PTSD)
        • End of life anxiety
      • Seizure (Status Epilepticus)
        • CNS depression can suppress the spread of seizure activity
        • IV lorazepam or diazepam are used
      • Alcohol withdrawal
        • Helps prevent autonomic dysregulation (Delirium Tremens)
        • Note that benzodiazepine withdrawal may also be treated with lorazepam
      • Insomnia/Sedative
        • May be used in setting of anesthesia
      • Antiemetic
      • Muscle spasm
    • Side Effects and Adverse Reactions
      • Sedation
        • Anterograde amnesia and sedation may be used in setting of anesthesia
        • If possible, give at bedtime to reduce daytime sleepiness
        • Elderly patients should avoid due to fall risk and potential to cause delirium
        • Caution patients against driving while taking benzodiazepines
      • Respiratory depression
        • Use with caution in combination with opioids, avoid alcohol
        • Contraindicated in sleep apnea, COPD, and respiratory depression
      • Withdrawal symptoms
        • Drug should not be abruptly stopped; taper if possible
        • Anxiety, insomnia, diaphoresis, tremors, hypertension, muscle twitching, seizures, headache, nausea/vomiting (same mechanism as alcohol withdrawal)
      • Tolerance / Dependence
        • High abuse potential
          • Schedule IV on Controlled substance act
      • Hypotension
      • Hepatotoxicity
        • Patient should receive baseline liver function tests
      • Sexual dysfunction
    • Antidote
      • Flumazenil