Lecture Notes: Benzodiazepines, Alternatives, and General Anesthetics

Introduction

• Topic: Sedative hypnotic drugs
  • Used for anxiety relief or inducing general anesthesia

Benzodiazepines (Benzos)

Overview

• Usage: Treat anxiety (anxiolytics), insomnia, epilepsy, alcohol detox, muscle relaxants, potentiation of CNS depressants in anesthesia
• Prescription: Mostly by Family Physicians, General Practitioners
• Characteristics: Instant relief for acute anxiety (unlike SSRIs which take weeks)

Pharmacokinetics

• Administration: Mostly oral, exceptions are midazolam (water-soluble, injectable)
• Abuse Potential: Lipid-soluble drugs like Xanax and Ativan can be abused
• Half-life: Varies by drug (short, intermediate, long-acting)
• **Notable Drugs and Half-lives: **
  • Midazolam: ~2.5 hours
  • Alprazolam (Xanax): ~12 hours
  • Clonazepam (Klonopin): ~30 hours
  • Diazepam (Valium): ~7-10 days in elderly

Side Effects

• Cognitive: Amnesia, confusion, potential dementia in elderly
• Physical: Fall risk, hip fractures in older adults, muscle relaxation
• Dependency: Potential for addiction, withdrawal issues
• Interactions: Increased risk with alcohol, opioids

Clinical Uses & Limitations

• Uses: Anxiety, insomnia, muscle spasm, alcohol dependence, panic attacks
• Limitations: Amnesic effects, risk of addiction, not effective for depression

Special Considerations

• Elderly experience prolonged effects due to metabolization issues
• Possible fetal abnormalities from benzodiazepine use by either parent
• Driving impairment, particularly severe in women

Alternatives to Benzodiazepines

Non-Benzodiazepine Benzodiazepine Receptor Agonists (BZRAs)

• Drugs: Zolpidem (Ambien), Zaleplon (Sonata), Eszopiclone (Lunesta)
• Uses: Primarily for sleep, not anxiety
• Side Effects: Hallucinations, sleep-driving, next-day sedation
• Risks: Potential for amnesia, acting while unconscious (e.g., driving, eating)

Cognitive Behavioral Therapy (CBT)

• Usage: Effective long-term treatment for anxiety, but takes months

General Anesthetics

Overview

• Purpose: Induce unconsciousness for surgery
• Administration: Inhalation or injection
• Types: Nitrous oxide, ultra-short acting barbiturates (thiopental), ketamine
• Key Points:
  • Central nervous system depressants
  • GABA agonism
  • Ketamine used in vet medicine, also has psychedelic effects

Important Considerations

• SSRIs: Used for chronic anxiety, different from immediate relief provided by benzos
• Naloxone & Flumazenil: Reversal agents for opioids and benzos respectively
• Caution: Always weigh benefits against significant side effects and risks