Clinical Psychopharmacology Notes

Pain Management & Drug Treatment

Chronic Pain

  • Definition: Persistent pain that lasts for weeks, months, or even years.
  • Causes: May arise from various conditions including nerve problems, disease processes, or after surgical interventions.
  • Types:
    • Nociceptive Pain:
    • Caused by stimulation of peripheral nerve fibers.
    • Includes:
      • Chemical Pain: Triggered by chemical irritants (e.g., chili powder).
      • Thermal Pain: Resulting from extreme temperatures (burning or freezing).
      • Mechanical Pain: Resulting from physical trauma (e.g., crushing, tearing).
    • Neuropathic Pain:
    • Caused by damage to the somatosensory system.
    • Often associated with conditions like diabetes, HIV, multiple sclerosis (MS), or chemotherapy-induced pain.
    • Phantom Pain: Pain perceived in a body part that is no longer there.
    • Incident Pain: Pain that accompanies certain activities or movements.
    • Breakthrough Pain: Sudden flare-ups of pain even when general pain control is effective.

Pain Transmission

  • Mechanism: Pain signals are transmitted from site of injury via specific pain sensors, along nerve fibers to the brain.
  • Inflammatory Response: Following injury, inflammation can increase sensitivity by activating more nerve fibers.

Analgesic Medications

  • Non-opioid Analgesics:

    • Acetaminophen: Commonly used for mild pain.
    • NSAIDs:
    • Are non-steroidal anti-inflammatory drugs, e.g., Aspirin.
    • Help reduce inflammation and pain.

  • Opioid Analgesics:

    • Strong analgesics such as:
    • Morphine
    • Hydromorphone
    • Codeine
    • Hydrocodone
    • Typically reserved for severe pain or postoperative pain management.

  • Adjuvant Analgesics:

    • Medications used to enhance the effects of analgesics, include:
    • Tricyclic Antidepressants
    • Anticonvulsants
    • Anesthetics (e.g., Novocaine, Lidocaine)

Treatment Considerations in Chronic Pain and Addiction

  • Addiction: Managing chronic pain in patients with addiction history is complex.
    • Medications:
      • Methadone: Often used as a maintenance treatment.
      • LAAM (Levo-alpha-acetylmethadol): Longer-acting alternative.
      • Naloxone: Used to counteract opioid overdose.
      • Buprenorphine: Can help in opioid addiction treatment.

Alcoholism and Associated Treatments

  • Dual Diagnosis: Understanding addiction alongside psychological or mood disorders:
    • Antabuse: For alcohol dependency treatment by causing adverse reactions when alcohol is consumed.
    • Naltrexone: Blocks the euphoric effects of alcohol.
    • Nalmefene: Similar to Naltrexone but with a different pharmacological profile.
    • Acamprosate: Helps maintain abstinence in people recovering from alcohol dependence.

Addiction Treatment Overview

  • General Treatment Guidelines:
    • Psychosocial Interventions: Trauma-focused therapies and managing co-occurring disorders.
    • Comprehensive Treatment Centers: Must include elements like harm-reduction settings, and encompass moral and disease models.
    • Key Considerations: Remember the history of chemical dependence even post-dependence control to avoid relapse.

Cocaine Addiction Treatments

  • Specific Management:
    • TCAs (Tricyclic Antidepressants)
    • Dopamine Agonists: Targeting the dopaminergic system which is often affected in addiction.
    • Ibogain: An experimental treatment.
    • Ritalin: Sometimes used due to its effects on dopamine levels.
    • Buprenorphine: Also applicable in treating cocaine addiction by managing cravings and withdrawal symptoms.