Chronic noncancer pain management

Chronic pain is pain that persists or recurs for more than 3 months. Unlike acute pain, which usually signals an injury or illness and dissipates as the body heals, chronic noncancer pain may not have a clear cause and persists long after an initial injury or illness has resolved. Clinical evaluation of chronic pain includes a comprehensive history, physical examination, medication review, and assessment of psychosocial factors. Diagnostic studies are not routinely recommended but should be considered if a serious underlying pathology or condition requiring specific management is suspected. Patient education and optimization of condition-specific analgesia are core components of chronic pain management. The WHO analgesic ladder can help clinicians select an appropriate pain management strategy based on pain severity and response to existing management. Multimodal nonpharmacological analgesia and/or nonopioid analgesics are the preferred initial management for chronic noncancer pain. Interventional pain management strategies may be beneficial for certain types of chronic pain (e.g., inflammatory or degenerative arthritis, complex regional pain syndrome). For chronic pain refractory to nonopioid management, opioid therapy may be considered only if benefits outweigh risks and additional precautions are taken (i.e., risk mitigation for opioid prescribing). Patients who are prescribed opioid therapy for chronic pain should receive close follow-up, and the risks vs. benefits of treatment should be regularly reassessed; opioids should be tapered or discontinued if the benefits no longer outweigh the risks.

Pain management in palliative care and management of acute exacerbation of chronic pain are detailed separately. For information on psychogenic pain, see “Somatic symptom and related disorders.”

Obtain a complete history and perform a physical exam, including: ^[1][2][3]

• Evaluation of pain and functionality, ideally with a validated scale such as the PEG pain scale ^[1][2]
• Assessment of social determinants of health, psychosocial well-being, and other potentially contributory factors ^[4]
• Medication review

• Imaging and diagnostic studies are not routinely recommended. ^[1][5][6]
• Consider imaging and further studies as needed to:
  • Exclude serious pathology (e.g., for patients with neurological deficits). ^[1]
  • Identify conditions requiring specific management (e.g., joint replacement for severe hip osteoarthritis).

Effective management of chronic noncancer pain often requires a multimodal approach, integrating various strategies tailored to the individual's needs and the type of pain. For pain related to cancer, sickle cell disease, or other high-morbidity illnesses, see “Palliative pain management.” ^[1][2][3]

• Optimize the following as needed:
  • Management of comorbid mental health conditions ^[1][7]
  • Condition-specific pain management
• Provide patient education on chronic pain management. ^[5]
• Consider enrolling patients into a pain management program (PMP). ^[5][8][9]
• According to the WHO analgesic ladder approach, initiate nonopioid management of chronic pain.
• Periodically reevaluate treatment efficacy using a validated tool to assess pain and functioning (e.g, the PEG pain scale). ^[2]
• For severe or refractory pain, interventional pain management strategies may be appropriate; consult a pain management specialist. ^[10][11]
• For pain refractory to the above measures, consider initiation of opioid therapy only if benefits outweigh risks.
  • Establish goals of treatment and an opioid exit strategy before initiation; use shared-decision making.
  • Continue nonopioid therapies in conjunction with opioid therapy.
  • Do not rapidly taper or abruptly discontinue opioid therapy once started.

A biopsychosocial model of medical care is integral to chronic noncancer pain management. ^[3]

Maximize the use of nonpharmacologic analgesia and nonopioid analgesics as appropriate for the condition. Opioids should only be initiated if the improvement in pain and function is anticipated to outweigh the risks to the patient. ^[1]

Avoid perpetuating existing racial and ethnic disparities in chronic pain management. ^[1]

Refer patients with these indications to a pain management specialist: ^[1]

• Age < 18 years ^[12]
• Pregnant individuals ^[13]
• Complex regional pain syndrome
• History of substance use disorder
• High morphine milligram equivalent (MME) prescription required ^[1]
• Refractory or severe pain
• Need for interventional pain management

Individuals without indications for referral to pain management can typically be managed by a primary care clinician.

• Ensure patients understand the diagnosis and how to manage their condition; see “Managing chronic conditions.”
• Provide pain neuroscience education. ^[5][14]
• Manage the patient's expectations, e.g., explain that: ^[1]
  • It can take weeks to months for pain to improve in response to treatment.
  • Goals should be realistic, e.g., pain reduction (not elimination) and improvement in function.
  • Chronic pain is managed in a stepwise manner.
• Educate patients on when to take medication for pain management.
• Support patients in developing a self-management approach. ^[5][15]

• Some conditions require specific pain management.
• Optimizing the management of underlying conditions may also reduce the need for analgesia.
• See:
  • Acute pain in sickle cell disease
  • Prophylactic therapy of migraine
  • Treatment of diabetic peripheral neuropathy
  • Treatment of osteoarthritis of the hip and knee
  • Treatment of fibromyalgia
• For pain related to cancer or other high-morbidity illnesses (e.g., chronic pain related to sickle cell disease), see “Pain management in palliative care.” ^[1]

A combination of multimodal nonpharmacological analgesia and various types of nonopioid analgesics may be used. To select the appropriate pharmacotherapy: ^[1]

• Assess for contraindications to nonopioid analgesics.
  • Evaluate for hepatic and/or renal impairment.
  • Determine the nature of any reported adverse effects of previous therapy.
• Consider pharmacology in older adults to minimize adverse effects.
• Determine the type and frequency of the pain (for dosages, see “Treatment of pain”).
  • Daily pain: Consider regularly scheduled nonopioid oral analgesia.
  • Breakthrough pain: Consider as-needed nonopioid oral analgesia.
  • Neuropathic pain: Consider regular adjuvant analgesics (e.g., anticonvulsants, antidepressants) or topical lidocaine or capsaicin.
  • Joint pain: Consider intraarticular glucocorticoid injection.
  • Radiculopathy: Consider epidural glucocorticoid injection.

There is insufficient evidence to support the use of cannabis or cannabinoids for chronic pain management; if being considered, check local laws before prescribing. ^[1][16]

Considerations before initiating opioids ^[1][9][17]

• Perform a thorough evaluation of chronic noncancer pain.
• Ensure nonopioid therapy for chronic noncancer pain has been maximized and alternative treatment options have been trialed.
• Check institutional and state guidelines for indications for opioid prescribing. ^[9]
• Determine if the patient has contraindications to opioids or risk factors for opioid-related harm.
• Discuss benefits and risks of opioid therapy with patient; ensure benefits outweigh risks, given type of pain and goals of treatment. ^[1]
  • Benefits: possible minor reduction in pain ^[1]
  • Risks
    • Adverse effects of opioids, including the development of opioid use disorder
    • Pain may worsen because of opioid-induced hyperalgesia.
    • May impact employment opportunities, especially in safety-critical jobs ^[1]
• If an opioid prescription is deemed appropriate, follow risk mitigation practices.

Ensure patients are aware that chronic use of opioids can interfere with employment opportunities, especially in safety-critical jobs. ^[1]

Before initiating opioid therapy, take a full patient history, screen for comorbid mental health conditions, and perform medication reconciliation to determine patient suitability for opioid therapy and to reduce modifiable risk factors.

Risk mitigation ^[1][9]

Consider risk mitigation for opioid prescribing prior to starting opioids and at each follow-up appointment.

• Assess for the development of contraindications to opioids or risk factors for opioid-related harm.
• Review:
  • State and federal laws relevant to prescribing controlled substances
  • The state's prescription drug monitoring program (PDMP)
  • Principles of prescribing for older adults, if relevant
• Prescribe naloxone and provide education on its use if any of the following are present: ^[18]
  • State requires coprescription
  • Risk factors for opioid overdose in patient or household members
  • Sleep-disordered breathing
• Provide counseling on the use of prescription opioids.
• Consider referral to a pain specialist and/or the use of buprenorphine for pain management in patients who: ^[19]
  • Require long-term daily opioids
  • Are unable to taper or discontinue opioids
  • Are at risk of opioid use disorder or have a history of opioid use disorder
• Avoid concurrent use of opioids and sedative-hypnotic medications (e.g., benzodiazepines, sleeping aids, muscle relaxants) or prescribe with extreme care.

Ensure patients with risk factors for opioid overdose have been provided with naloxone and educated on how to use it. ^[1]

The prescription of more than a 90-day supply of opioids is associated with a dose-dependent increase in the risk of adverse effects of opioid use, including opioid use disorder. ^[1]

Aberrant drug-related behaviors

Aberrant drug-related behaviors may suggest abuse, misuse, or diversion of opioids.

• Concerning behaviors include: ^[20][21]
  • Obtaining medication from nonmedical sources
  • Requesting prescriptions early
  • Frequently reporting loss of prescriptions
  • Missing or canceling appointments at which no opioid refill is anticipated
  • Obtaining prescriptions from multiple providers
  • Presenting to the emergency department for medications
• Managing patients with aberrant drug-related behaviors
  • Do not discharge patients from care unless they are violent or threatening. ^[1][22]
  • Evaluate for opioid use disorder and/or other substance use disorders; if present, provide treatment with a multidisciplinary team.

Urine drug monitoring for opioid therapy ^[23][24]

• Consider urine toxicology prior to starting opioid therapy and at least annually thereafter. ^[1][23]
• Communicate clearly with patients to reduce misunderstandings.
  • Explain urine drug monitoring procedures and their purpose in maintaining patient safety.
  • Ask nonjudgmentally about the nature and timing of all recent substance use before ordering a test.
• Interpret results with care.
  • Screening immunoassays have limitations; ask patients nonjudgmentally about any unexpected results. ^[1][23][24]
  • If results are unexplained and/or will affect management, obtain confirmatory testing. ^[1][23]
  • Do not use results punitively (e.g., discontinuation of opioids, discharge from practice).

Initiating opioids ^[1][2][9]

• Establish the following, using shared decision-making.
  • How and when treatment efficacy will be assessed: Patients should experience functional gains as measured, e.g., with the PEG pain scale. ^[17]
  • An opioid exit strategy: how opioids will be discontinued or how to transition to medication-assisted treatment if the risks outweigh the benefits
• Create a controlled substance agreement and ensure informed consent has been obtained in the appropriate form. ^[9]
• Provide anticipatory guidance to avoid adverse effects of opioid use.
• Establish dosing and frequency based on the pharmacology of opioids (see “Treatment of pain” for specific dosages). ^[1]
  • Initiate therapy with immediate-release short-acting opioids.
  • Start with a low dose and titrate to the lowest effective dose.
• In patients with hepatic or renal impairment, consider longer dosing intervals.
• Prescribe as needed rather than scheduling doses. ^[1]
• Create a plan for events requiring acute-on-chronic pain management.
• Follow-up within 1–4 weeks after initiating therapy to evaluate for improved functioning and pain control. ^[1]

Ongoing therapy ^[1][9]

• Follow-up:
  • At least every 3 months to evaluate efficacy and safety ^[1]
  • More frequently for patients with a high risk of overdose or misuse ^[1]
• Continue to:
  • Maximize nonopioid management of chronic noncancer pain.
  • Follow risk mitigation for opioid prescribing at every visit, including consideration of urine drug monitoring for opioid therapy at least annually.
• Maintain accurate records at every visit, including:
  • Calculated daily MME
  • Average daily pain level
  • Functional assessment (e.g., ability to perform ADLs, score on PEG pain scale)
  • Adverse effects
  • Aberrant drug-related behaviors
  • Confirmation of review of the state's PDMP ^[1]
• Convert from immediate-release to extended-release opioids only if:
  • Pain is ongoing, severe, and constant
  • Patient has opioid tolerance (when relevant) ^[25]
• If transitioning from one formulation to another, reduce the MME of the new formulation initially.

There is a paucity of evidence supporting > 12 months of opioid therapy for chronic pain management. ^[1][17]

Prescriptions ≥ 50 MME/day are unlikely to improve pain and also increase the risk of adverse effects of opioids. ^[1]

Tapering

The decision to taper chronic opioid therapy (and, possibly, to discontinue therapy) should be made on an individual basis using shared decision-making, weighing up the benefits and risks of opioid therapy. ^[1][9]

The goal of tapering may be complete discontinuation or dose reduction to improve the risk versus benefit profile. ^[1]

Indications ^[1][17]

Consider tapering in the following scenarios:

• Patient request
• Resolution of pain
• Lack of response to therapy, e.g.:
  • Inadequate improvement in quality of life, function, or pain scores
  • Escalation of dosages without improvement
• Adverse effects of opioids impacting quality of life
• Evidence of diversion of prescription drugs or misuse (aberrant drug-related behaviors)
• Overdose event or concern for impending overdose ^[1]
• Risk factors for opioid-related harm

Consult a pain specialist if considering tapering opioids in pregnant individuals. ^[1]

Process ^[1][9]

• Use a multidisciplinary approach.
• Avoid rapid tapering and sudden discontinuation.
• Advise patients that pain may worsen initially.
• First, reduce the dose per administration.
  • Maximize nonopioid therapy for chronic noncancer pain.
  • Determine tapering speed based on duration of opioid use: ^[1]
    • < 1 year: Taper at ≤ 10% of the original dose per week.
    • ≥ 1 year: Taper at ≤ 10% of the original dose per month.
  • Slow the taper if signs of withdrawal develop.
• Once the lowest dose per administration has been achieved:
  • Gradually increase the dosing interval.
  • Discontinue opioids when the interval is less than once daily.
• Follow-up monthly during tapering
  • Consider the patient's wishes to slow or pause the taper.
  • Evaluate for and manage complications of opioid tapering

Do not rapidly taper or discontinue opioids unless the patient is at imminent risk for life-threatening complications such as overdose. ^[1]

Inform patients that they are at increased risk for overdose during and shortly after tapering because of decreased tolerance. ^[1]

Most patients on long-term opioid therapy who agree to taper or discontinue opioids experience overall satisfaction, with improved quality of life and no increase in pain, but may experience short-term effects of hyperalgesia, insomnia, and agitation. ^[1]

Management of complications ^[1]

• Development of opioid withdrawal symptoms
  • Slow or pause the taper.
  • Consider medications for opioid withdrawal.
• Inability to taper or discontinue because of ongoing pain
  • Maximize nonopioid therapies for chronic noncancer pain
  • Consider referral to a pain specialist and/or the use of buprenorphine for pain management.
• Unmasking of opioid use disorder: See “Treatment of opioid use disorder.”
• Development or unmasking of depression and/or anxiety
  • See “Major depressive disorder” and “Anxiety disorders.”
  • Involve mental health professionals in care as needed.
• Overdose due to decreased tolerance: Prescribe naloxone. ^[18]
• Development of aberrant drug-related behaviors: Engage multidisciplinary team care and address any underlying substance use disorders.