Pain Management in HIV/AIDS

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Pain Management in HIV/AIDS

• Peter A. Selwyn, M.D., M.P.H.
• Professor and Chairman
• Department of Family and Social Medicine
• Montefiore Medical Center
• Albert Einstein College of Medicine

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Pain Management in AIDS

• High prevalence of pain in AIDS
• 29-76 of patients, higher with advanced
  disease.
• Pain may be due to
• - Effects of specific opportunistic infections
• headache cryptococcal meningitis
• abdominal pain disseminated m.
  avium complex
• cutaneous pain herpes zoster
• odynophagia esophageal candidiasis
  
• - HIV itself distal symmetric polyneuropathy
• - HIV medications dideoxyoside-related
  peripheral neuropathy,
• isoniazid-related neurotoxicity
• Pain often undiagnosed/untreated in patients with
  AIDS.
• Important to treat pain in order to improve
  quality of life, relieve suffering, and improve
  HIV treatment adherence and outcomes.

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Classification of Pain

• nociceptive pain from the stimulation of intact
  nociceptors (or pain receptors).
• somatic pain - - nociceptors in skin, soft
  tissue, skeletal muscle and bone
• visceral pain - - nociceptors in internal
  visceral organs.
• neuropathic pain from stimulation or abnormal
  functioning of damaged sensory nerves,
  primarily in the peripheral nervous system.

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Taking a Pain History

• Key features frequency, duration, intensity.
• Standard scale 0-10, with 0 as no pain and
• 10 as the worst pain ever experienced.
• Precipating factors, location, characteristics of
  pain.
• Nociceptive pain commonly aching,sharp,
  throbbing, gnawing, or spasmodic.
• Neuropathic pain commonly burning, tingling,
• numb, like pins and needles or an electric
  shock

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Treatment of Pain

• Use WHO analgesic ladder for mild, moderate,
  and severe pain.
• Adjuvant medications particularly helpful for
  neuropathic pain.
• Mild Pain (1-3 on 0-10 scale) non-opioid
  analgesics with or without adjuvants.
• Non-opioid analgesics ibuprofen, ASA,
  paracetamol, acetaminophen
• Adjuvants amtriptyline, imipramine, gabapentin,
  carbamazepine
• Moderate Pain (4-6 on 0-10 scale) weak opioids
  with or without
• adjuvants.
• Weak opioids codeine, hydrocodone
• Severe Pain (7-10 on 0-10 scale) strong opioids
  with or without
• adjuvants.
• Strong opioids morphine, oxycodone, methadone

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• Figure 1. The WHO three-step analgesic ladder

Pain Relief
Pain persisting or increasing
3 SEVERE PAIN
Strong Opioid /- Non-opioid /- Adjuvant
Pain persisting or increasing
2 MODERATE PAIN
Weak Opioid /- Non-opioid /- Adjuvant
1 MILD PAIN
Non-opioid /- Adjuvant
Adapted from World Health Organization. Cancer
Pain Relief. Geneva WHO, 1990.
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Medication and Dosing Data for Acetaminophen,
Non-Steroidal, Antinflammatory Agents (NSAIDs),
and Adjuvant Medications for Chronic Pain.
Table 1
Acetaminophen and NSAIDS Acetaminophen Aspirin (ASA) Ibuprofen Indomethicin Usual P.O. dose for adults 650 mg q 4 h 975 mg q 6 h (maximum 4gm/day) 400-800 mg q 6 h 10-25 mg tid
Adjuvant Medications for Neuropathic and Chronic Pain Adjuvant Medications for Neuropathic and Chronic Pain
Anticonvulsants Carbamazepine Gabapentin Phenytoin Antidepressants Amitriptyline Imipramine Trazodone Benzodiazepines Clonazepam Usual daily oral dose range 200-1600 mg 900-1800 mg 300-500 mg 25-100 mg 20-100 mg 75-225 mg 1.5-6 mg
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Equianalgesic and Starting Doses of Opioids
Table 2
Drug Approximate equianalgesic dose Approximate equianalgesic dose Approximate equianalgesic dose Usual starting dose for moderate to severe pain Usual starting dose for moderate to severe pain
Oral Parenteral Parenteral Oral Parenteral
Opioid agonist Opioid agonist Opioid agonist Opioid agonist Opioid agonist Opioid agonist
Morphine 30mg q 3-4 h 10mg q 3-4 h 30mg q 3-4 h 30mg q 3-4 h 10mg q 3-4 h
Hydromorphone 7.5mg q 3-4 h 1.5mg q 3-4 h 6mg q 3-4 h 6mg q 3-4 h 1.5mg q 3-4 h
Methadone 15mg q 6-8 h 10mg q 6-8 h 15mg q 6-8 h 15mg q 6-8 h 10mg q 6-8 h
Hydrocodone 30mg q 3-4 h N/A 10mg q 3-4 h 10mg q 3-4 h N/A
Oxycodone 30mg q 3-4 h N/A 10mg q 3-4 h 10mg q 3-4 h N/A
Codeine 180-200mg q 3-4 h 130mg q 3-4 h 60mg q 3-4 h 60mg q 3-4 h 60mg q 2 h
May be available in fixed dose tablet
combination with acetaminophen or aspirin.
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Opioid Dosing Requirements

• Most short-acting opioids need to be given every
  4 hours to maintain effect.
• Patients become tolerant to the analgesic effects
  of opioids, which may require dosage increases
  over time.
• For chronic pain, give on scheduled rather than
  as needed basis.
• May need to change from one opioid to another
  (due to side effects or treatment failure)
  become familiar with equi-analgesic dose
  conversions, starting with slightly lower
  equivalent dose of the new drug and titrating
  upwards.

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Concept of Total Pain

• Physical
• Psychological
• Social
• Spiritual
• C.Saunders, 1967

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Opioid Side Effects and Treatment
Table 3
Common Side Effects Sedation (decreases over time) Dysphoria Constipation Nausea-vomiting Treatment None required (unless excessive) Haloperidol, benzodiazepines Laxatives (senna, docusate, fiber) Anti-emetics (prochlorperazine, metaclopramide, haloperidol)
Suggestive of Over-Medication Excessive sedation Respiratory depression (lt6 breaths/mn) Severe dysphoria/agitation Hyperalgesia (paradoxical increase in pain) Treatment ? dose or change opioid ?dose (narcotic antagonists if severe) ?dose or change opioid ?dose or change opioid
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Pain Management in Substance Users

• Assessment
• - Validity of self-report
• - Pain threshold
• - Multiple sources of pain
• - Drug seeking behavior
• - Provider prejudices
• Treatment
• - Tolerance
• - Dependence
• - Least tempting alternative
• Harm reduction
• - Consistency
• - Limit-setting
• - Decrease risk of abuse

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Pain Management in Substance Users Implications
of Tolerance and Dependence

• Higher doses of narcotics may need to be given,
  on a more frequent dosing schedule, in
  opioid-tolerant individuals.
• Opioid withdrawal symptoms, a sign of physical
  dependence, may include generalized discomfort
  and other symptoms that may be interpreted as
  pain. History of other distinctive opioid
  withdrawal symptoms can be useful in
  differentiating pain from abstinence syndromes.
• Longer-acting narcotics may be helpful in
  reducing withdrawal symptoms when present.

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Concerns about Opioid Addiction and Abuse

• Patients receiving opioids for pain rarely become
  addicted and do not exhibit pathological
  behaviors associated with drug abuse.
• A history of drug abuse should not be a
  contra-indication to opioid analgesic therapy
  when needed for pain.
• Safeguards to help prevent abuse and diversion of
  opioids
• Limiting the amount of medication dispensed to
  the patient at any one time.
• Adhering to a fixed schedule for renewing the
  patients supply of medication.
• Assessing the patient for evidence of drug abuse
  (fresh injection marks on the skin, suspicious
  behavior, or poor adherence with medical
  therapy).
• Using non-opioid-containing regimens when
  possible.

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System and Policy-Level Safeguards to Prevent
Opioid Misuse

• Establishing systemic and institutional controls
  and protocols for handling of opioid medications.
• Having safe and secure facilities for storage of
  controlled medications.
• Following strict inventory procedures, accounting
  and accountability practices for clinical staff
  involved in handling these medications.
• Following WHO guidelines for national policy and
  programs for opioid drug availability.
• (WHO 1995, 2002)