Opioids and Pain Control February 21, 2006

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Opioids and Pain ControlFebruary 21, 2006

• MAJ William Starnes, PharmD

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Learning Objectives

• Upon completion of this program, successful
  participants will be able to
• Manage the appropriate use of opioids for chronic
  pain.
• Identify and treat adverse reactions associated
  with opioid use.
• Recognize barriers to effective use of opioids.

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Introduction

• Pain
• Opioid use
• Chronic pain
• Trauma
• Causes of treatment failure
• Barriers to adequate pain control
• Dependence vs. Addiction

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Pain

• An unpleasant sensory and emotional experience
  associated with actual or potential tissue damage
  or described in terms of such damage.

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Nociceptive Pain

• Normal sensory nerve fibers are stimulated by a
  noxious stimulus
• Somatic pain
• Visceral pain

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Neuropathic Pain

• Caused by damage the central or peripheral
  nervous systems resulting in abnormal
  transmission and/or processing of sensory
  information.

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Chronic Non-Cancer Pain

• Pain related history
• Prior treatment
• Pain-related fear
• Interference with function.
• Social history.
• Substance use history.

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Absolute Contraindications

• Allergy.
• Drug-drug interactions.
• Active diversion of controlled substances.

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Relative Contraindications

• Acute psychiatric instability.
• Intolerance.
• Serious adverse effects.
• Lack of efficacy.
• Substance abuse disorder.

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Indicated At This Time?

• Has patient failed a course of non-opioid
  treatment?
• Ethical imperative to relieve pain.

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Treatment Agreement

• Goals of therapy.
• Single provider.
• Limit on number and dose of medications.
• No alcohol, sedating meds, or illegal drugs.
• Risky behavior/actions.

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Treatment Agreement (cont)

• Limiting refills.
• Compliance.
• Education.
• Periodic re-evaluation.
• Consequences of non-adherence.

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Patient Considerations

• Type of pain
• Nociceptive.
• Neuropathic.

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Opioid Therapy

• Trial consists of phases
• Initiation
• Titration
• Maintenance
• Choice of Agent
• Short acting
• Long acting

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Initiation

• Best pain relief and fewest adverse effects.
• Short vs. long acting.
• Low test dose.
• One med at a time.

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Titration

• Adjust dose.
• Assess response.
• Failure to respond, consider rotating meds.
• Rescue opioids.
• Equianalgesic conversion.

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Maintenance

• Repeating effective dose on a routine schedule.
• Do not lower dose that provides relief.
• Supplemental short-acting meds.
• Reassess every 1-6 months.

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Dosing Considerations

• Time-contingent.
• PRN.
• Predetermined max dose.
• To-effect dosing.
• Titration.
• Equianalgesic conversion.

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Adverse Effects

• Nausea/Vomiting.
• Constipation.
• Drowsiness.
• Pruritis.
• Confusion.
• Dizziness.
• Somnolence.

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Allergies

• True allergies very rare.
• Consider switching to another chemical class
• Phenanthrene.
• Diphenylheptanes.
• Phenylpiperidines.

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Management of Adverse Effects

• Anticipate.
• Treat/prevent,
• Nausea/vomiting
• Constipation
• Itching
• Cognitive effects.
• Perceptual/affective effects.
• Sexual dysfunction.

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Meds to Treat Adverse Effects
Condition
Meds
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Short-acting Agents

• Codeine.
• Hydrocodone.
• Hydromorphone.
• Morphine.
• Oxycodone.
• Propoxyphene.
• Tramadol.

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Long-acting Agents

• Morphine CR.
• Oxycodone CR.
• Fentanyl transdermal.
• Levorphanol.
• Methadone.

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Equianalgesic Conversion

• Opioid rotation.
• Various equianagesic dosing tables available.
• Many factors influence choice of starting dose.

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Opioid Equianalgesic Table
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Causes of Treatment Failure

• Inappropriate/unknown diagnosis.
• Pharmacology/kinetics.
• Adverse Effects.
• Fear of addiction.
• Unrealistic goals.
• Irrational polypharmacy.
• Patient barriers.
• Lack of pain knowledge.

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Societal Perceptions

• Youre a wimp.
• I dont see why it hurts, so youre not hurt.
• Just work through it.
• Just take an aspirin.
• Its not that bad.
• You just want drugs.

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Provider Barriers

• Fear of legal ramifications.
• Known adverse effects.
• Need to increase dose.
• Potential addiction and abuse.
• Inability to predict effectiveness.
• Lack of belief in patients complaint.
• Complexity of monthly prescriptions.
• Dealing with co-morbidities.

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Chronic Use of Opioids

• Physical dependence.
• Tolerance.
• Addiction.
• Pseudoaddiction.

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Physical Dependence

• Physiologic state.
• Withdrawal syndrome.
• Expected occurrence.
• Does not imply addiction.

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Tolerance

• Neuroadaptation to effects of chronic use.
• Occurs to both analgesic and adverse effects.
• Does not imply addiction.

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Addiction

• Persistent pattern of dysfunctional use.
• Loss of control over use.
• Preoccupation with obtaining opioids.
• Continued use despite adverse consequences.

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Pseudoaddiction

• Describes behavior when pain is under treated.
• Focused on obtaining medications.
• Behavior resolves when effectively treated.
• May inappropriately stigmatize patient.

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Pain Management in Trauma

• Increase comfort.
• Reduce morbidity.
• Improve long-term outcome.
• Neuroplasticity and chronic neuropathic pain.

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Inadequately Treated Acute Pain

• Cytokine release.
• Increased Catecholamines.
• Activation of the RAAS.
• Impaired coagulability.
• Altered immune response.
• Potentiate adverse effects of trauma i.e.
  ventilation, hemodynamic stability, etc.

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Specific Types of Trauma

• Blunt chest trauma.
• Burn injuries.
• Phantom and stump pain.
• Spinal cord injuries.
• Traumatic head injuries.

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Questions?
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Summary

• Use of opioids in chronic pain
• Considerations to effective management
• Barriers to effective therapy
• Patient barriers
• Provider barriers
• Trauma

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References

• AphA 2005 Pain Management Joint Summit. American
  Pharmacists Association Highlights Newsletter
  2005 9(4).
• Ballantyne J, Mao J. Medical Progress Opioid
  Therapy for Chronic Pain. New England Journal of
  Medicine 2003 349 1943-1953.
• Cohen S, Christo P, Moroz L. Pain Management in
  Trauma Patients. Am J Phys Med Rehabil 2004
  83142-161
• Ineck J. Pharmacist pain management a focus on
  opioid and conversion issues. Drug Store News
  2005 15-20.
• Pawasauskas J, Use of opioids in the treatment of
  chronic pain. Drug Store News 2003 3-8.
• VA/DoD Clinical Practice Guideline for the
  Management of Opioid Therapy for Chronic Pain.
  Department of Veterans Affairs and Department of
  Defense. Version 1.0