assessing & managing pain

7/27/2019 Assessing & Managing Pain

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The Center for Palliative Care Education

Assessing and ManagingPain in HIV/AIDS


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Learning objectives

Understand the common etiologies and thediagnostic evaluation for pain in HIV/AIDS

Know characteristics of and treatmentapproaches for nociceptive vs. neuropathicpain

Describe pitfalls in treating pain in patients

with substance abuse


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Overview

Case I: 35 M with HIV

Neuropathic pain

Case 2: 60 F with HIV and avascular necrosis

Nociceptive pain


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Case 1

35-year-old HIV+ man on antiretroviraltherapy:

Burning, shooting, lower extremity pain

Intermittent

Not responsive to oxycodone/acetminophen(Percocet)

Neuro exam unremarkable


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Neuropathic pain syndromeswith HIV/AIDS

HIV neuropathy, myelopathy

Antiretroviral medication (dideoxynucleosides)

Chemotherapy


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Additional causes ofneuropathic pain

Herpes zoster

Diabetes

Multiple sclerosisAlcoholism

Amputation (phantom limb)


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Neuropathic pain

Pain may exceed observable injury

Described as: burning, tingling, shooting,

stabbing, electrical Management:

Adjuvant medications


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Pain assessment

History: Quality, timing of pain

Exam: Neuropathy, color, skin temperature,sensation

Watch for: Allodynia (pain from mildstimulation, such as touching or rubbing)

Use 0 10 scale


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Pain management

Switch antiretroviral medication if suspicion is high

Dont delay for investigations or disease treatment

Unrelieved pain causes nervous system changes:

Permanent damage

Amplification of pain

Address underlying cause where possible


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Evidence-based treatmentof neuropathic pain

Amitriptyline 10-75 mg po qhs:

No placebo-controlled trials for HIVneuropathy

+ controlled trials for diabetic neuropathy Gabapentin (Neurontin) 100-800 tid:

Widely used, renally cleared

Lamotrigine (Lamictal):

200-400 mg qd

Rare Stevens-JohnsonsLa Spina; Eur J Neurol 2001; 8:71-

Simpson; Neurology 2000; 54:2115-


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Evidence-based treatment ofneuropathic pain

Topical Capsaicin (Zostrix): Often not welltolerated

Topical Lidocaine gel

Acupuncture: A negative trial in HIV Phenytoin: Occasional responders, no +

controlled trials

Mexiletine: No better than placebo (ACTG242)

Paice; J Pain Symptom Manage 2000; 19:45-52

Shlay; JAMA 1998; 280:1590-5

Kieburtz; Neurology 1998; 51:1682-8


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Case 1: Management

HIV meds switched to non-ddI regimen

Trial amitriptyline 10 mg qhs escalated to 100mg qhs over 2 weeks

Mild relief but still very bothersome

Gabapentin 100 mg tid escalated to 300 mg tidover 2 weeks

Substantial relief


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Summary points: Case 1

Neuropathic pain:

Characteristic history

Physical findings incl AllodyniaNeed adjuvant meds (Gabapentin)

May also need opioids


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Case 2

60 F HIV+ x 7 years

Presented with aching hip pain, worse at night

Diagnosed with avascular necrosis related to

HIV

Treated with calcium

Started on oxycodone/acetaminophen 5mg 6x/d

PMH alcohol abuse


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Nociceptive pain

Direct stimulation of intact nociceptors (painreceptors)

Transmission along undamaged nerves

Quality of pain: aching, throbbing

Somatic: easy to localize

Visceral: difficult to localize


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Nociceptive pain

Tissue injury apparent

Management:

OpioidsCo-analgesics (NSAIDS) when

possible


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WHO 3-step ladder

Morphine

Hydromorphone

Methadone

Levorphanol

Fentanyl

Oxycodone

Adjuvants

3 severe

2 moderate

A/Codeine

A/Hydrocodone

A/Oxycodone

A/Dihydrocodeine

Adjuvants

1 mildASA

Acetaminophen

NSAIDs

Adjuvants


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Acetaminophen

WHO Step 1 drug

Site, mechanism of action unknown

Minimal anti-inflammatory effect Hepatic toxicity if > 4 g / 24 hours:

increased risk

hepatic disease, heavy alcohol use

N t id l ti i fl t


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Non-steroidal anti-inflammatorymedications (NSAIDS)

WHO Step 1: Analgesic, coanalgesic

Inhibit cyclo-oxygenase (COX):

Vary in COX-2 selectivityAll have analgesic ceiling effects:

Effective for bone, inflammatory pain

Individual variation, serial trials


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NSAIDs

Highest incidence of adverse events

Gastropathy:

gastric cytoprotectionCOX-2 selective inhibitors


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Short-acting opioids

WHO Step 2:

Short-acting opioids combined withacetaminophen

Useful for moderate pain

Short half-life (3-4 hours at most)

Use limited by limitations of acetaminophen


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Opioids: Routine oral dosing

WHO Step 3:

Use extended-release preps (morphine SR) toimprove compliance, adherence

Dose q 8, 12, or 24 h (product specific):

Dont crush or chew tablets

Adjust dose q 24 days (i.e., once steady state

reached)


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Morphine dosing

Escalate until pain is relieved

Refrain from combining opiates

Consider documenting a pain plan in the chart Low opioid dosing for chronic, non-malignant

pain is an option


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Opioids: Breakthrough dosing

Use immediate-release opioids (morphine IRor elixir):

5%15% of 24-h dose

Do NOT use extended-release opioids forbreakthrough pain


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Opioids: Essential pharmacology

Conjugated by liver

90%95% excreted in urine

If dehydration, renal failure, severe hepatic failur:

dosing interval, dosage sizefor oliguria or anuria

STOP routine dosing of morphineuse ONLY prn


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Not recommended Meperidine (demerol)

Mixed agonists-antagonists (Talwin)


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Opioid Side Effects

Constipation

Drowsiness

Neuropsychiatric symptoms, includingvivid or bad dreams

Myoclonic jerks

Delirium


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Switching Opioids

Consider switching if dose-limiting toxicitydevelops

Use an equianalgesic chart

Adjust the new dose for incomplete crosstolerance

Start with about 2/3 the new calculated dose


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Switching Opioids Example

60 mg morphine SR q12h (120 mg/24 hours)

To convert to SR oxycodone:

Equianalgesic dose: 120 mg/1.5=80 mg

New dose: 2/3 x 80 = 55 mg

Start with SR oxycodone 30 mg q 12h

Approach to managing


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Approach to managingsubstance abuse

Respect patients report of pain

Distinguish between tolerance and addiction(psychological dependence)

Distinguish between active users and those inrecovery

Approach to managing


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Approach to managingsubstance abuse

Set clear goals for opioid therapy-identify and discuss abuse behaviors

-use written contracts

-establish single provider

Use a multidimensional approach:

-attention to psychosocial issues

-team approach

Reflect on your own attitudes towards substance abuse


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Is use of opioids appropriate?

Literature for cancer pain and substanceabuse suggests:

Relapse of substance abuse occurs but

is not common

Under treatment of pain contributes tosubstance abuse

Clear limits are needed

Pitfalls in treating patients


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Pitfalls in treating patientswith substance abuse

Not believing pain reports

Not prescribing adequate pain meds

Not setting clear limits regarding prescriptions Clinician attitudes

Having multiple clinicians prescribe

C 2 M


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Case 2: Management

Taking percocet 5mg 6x/d

Changed to long-acting oxycodone 30 mgq12

Morphine IR 10 mg q1 hour prnbreakthrough pain

Bowel regimen: 4 glasses water, senekot2 tabs qhs

Improved mood, activity

S i t C 2


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Summary points: Case 2

Severe nociceptive pain often requires opioids

Use long- and short-acting opioids together

Treating patients with substance abuse withopioids can be successful

Contributors


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Contributors

Anthony Back, MD Director

J. Randall Curtis, MD, MPH Co-Director

Frances Petracca, PhD Evaluator

Liz Stevens, MSW Project Manager

Visit our Website at uwpallcare.org

Copyright 2003, Center for Palliative Care Education, University of Washington

This project is funded by the Health Resources and Services Administration (HRSA) and the Robert Wood Johnson Foundation (RWJF).

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