Aspects of Managing Severe Pain

Palliative Care Summer Institute

Aspects of Managing Severe Pain


Opioid RotationOpioid Neurotoxicity

Opioid Equianalgesic DosingAdjunct medications


Opioid Rotation Indications

Poor analgesia despite increasing dosesAdverse effects are intolerable, toxicityNeed different route of administrationChange in clinical status (drug abuse?,malabsorption)

Financial/drug shortage considerations

-Fine and Portenoy: “Best Practices for Opioid Rotation JPSM 9 2009


Opioid Rotation

• 30% pts need new route (severe nausea, mucositis)

• Controlled Pain: reduce dose for incomplete cross tolerance

• Uncontrolled pain = use equianalgesic dose• Toxicity: Lower dose, treat side effects, use

adjuvants• Prevent toxicity by:• Using opioids cautiously renal or hepatic

dysfunction• Intestinal colic Rx: Decadron,

Glycopyrrolate, Octreotide


Opioid Rotation Guidelines

Calculate Equianalgesic Dose using tableSevere pain = use equianalgesic doseMod pain or other route-lower this 25-50% (incomplete cross tolerance)

Double check calculations (measure twice, cut once)

Methadone-non linear conversionReassess frequently


Opioid Equianalgesic DosingEQUIANALGESIC DOSES OF OPIOIDS

Analgesic Oral/Rectal mg = IV/SQ mg

Morphine 30 10

Hydromorphone 7.5 1.5

Oxycodone 20 ---

Hydrocodone 30 ---

Codeine 200 130

Fentanyl --- 0.1mg = 100mcg

Methadone see ratios below 1/2 Oral=IV Dose


Opioid Rotation GuidelinesMETHADONE CONVERSION RATIOS Oral Morphine

Daily Dose MS:MEExamples

MSmg:MEmg

0-100 3:1 100:33

101-300 5:1 300:60

301-600 10:1 600:60

601-800 12:1 800:60

>1000 20:1 1200:60


Opioid Neurotoxicity-Dx & Assessment

Occurs with escalating doses (3 Glucuronide metabolites):

• Frequency of myoclonic jerks• Hyperalgesia (allodynia)• Delirium, hallucinations, seizuresCommon risk factors: • Dehydration, • Drugs: (haldol, phenothiazines)• Renal, hepatic dysfunction, Mg+

+, Na+


Opioid Neurotoxicity-TreatmentObservation

Opioid dose reductionOpioid rotation

AdjuvantsBenzodiazepines

Hydration


Morphine : Fentanyl

Morphine Oral mg

Morphine IV mg

Fentanyl IV mcg/hr

30 10 100*

720 240 2400

100 30 50mcg/hr patch**


IV Morphine : Fentanyl patch

• 1st 6 hrs: bolus IV morphine• 2nd 6hrs MS infusion at ½ the

equianalgesic dose (100mcg fentanyl=MS 5mg/hr)

• >12 hrs start full conversion (10mg/hr)


Methadone

NMDA receptor antagonist, mu opioid agonistExcellent in opioid tolerance, neuropathic painLong half lifeHigh oral bioavailabilityNo active metabolitesInexpensiveProlonged QT concerns, so:• Start low, go slow• Limit to <100mg/day


Ketamine

NMDA receptor antagonistAnesthetic, sedative, powerful analgesicSpares opioids-decrease opioids 25% initially, 25-50% @6-12 hrs and as needed until equilibriumBenzodiazepine helpsPsychomimetic side effectsConsider adding@ 100mg/hr morphine

1000mcg/hr fentanylInitiate 80 mcg/kg/hr IV/SQContinuous infusion 80-600 mcg/kg/hr


Lidocaine

Sodium channel blockerGood for neuropathic painIV/SQ infusion: Bolus 1-2mg/kg, then 0.2-1mg/kg/hrTitrate to effectDecrease opioid dose 50% every 6-12 hrs thereafterMay have twitching at high doses


Other Adjuncts

GabapentinBisphonphonatesAntidepressantsAnticonvulsantsMuscle relaxantsLocal anestheticsCannabinoidsTopical agents


Interventional Procedures

Trigger point injectionsNerve blocksEpidural and Intrathecal cathetersEBUS celiac plexus blocks


Symptom Management Guides

Tarascon Palliative Medicine Pocketbook

Symptom Management Algorithms

EPERC FAST FACTSOur Hospice Nurses

Hoagland’s Hospice PharmacistsAngie, Bree, Meg, Shaun 360

733-5877

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Aspects of Managing Severe Pain