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.