Chronic Pain Management Case File

Chronic Pain Management Case File

Eugene C. Toy MD, Donald Briscoe, MD, FA  AFP, Bruce Britton, MD, Joel J. Heidelbaugh, MD, FA  AFP, FACG

Case 59

A 58-year-old woman with known metastatic breast cancer presents for a follow up visit. She was diagnosed with breast cancer 2 years ago, at which time she underwent a lumpectomy and local breast radiation therapy. Subsequently, she was found to have metastases to her thoracic spine and has started chemotherapy under the management of an oncologist. You have been trying to manage her pain with hydrocodone/acetaminophen, which provides temporary relief, but the pain returns a few hours after taking her pills. She has purposely been taking less than the recommended dosage in order to avoid addiction, and waits until the pain is severe before taking them. On average, she uses four to six hydrocodone/ acetaminophen pills daily. The patient also complains of chronic constipation over the last few years. Her appetite is reduced by the chemotherapy, and the associated bloating and constipation make her not want to eat at all. Her last bowel movement was 4 days ago and she only has bowel movements when she uses enemas. On examination, she is wearing a bandana that covers her hair and does not appear cachectic. Her abdomen has hypoactive bowel sounds, and is mildly distended, firm, and tender to palpation without rebound or guarding.

⯈ What is the likely cause of her constipation?

⯈ What can you do to improve her pain control?

⯈ How do you address her concerns about narcotic addiction?

ANSWER TO CASE 59

Chronic Pain Management

Summary: A 58-year-old woman with pain from bone metastases from breast cancer presents for follow-up of her pain management. She is using a short-acting narcotic/acetaminophen combination that modestly relieves her pain when she uses it, but she limits its use out of concern for addiction. She also has developed significant constipation.

• Most likely cause of her constipation: Side effect of her narcotic use.
• Steps to improve her pain control: Begin an extended-release opioid analgesic, such as extended-release morphine or fentanyl patches, with the addition of a short-acting opioid for breakthrough pain.
• Steps to address her concerns about addiction: Explain to her that addiction rarely occurs when pain medications are used as directed for the management of chronic pain.

ANALYSIS

Objectives

1. Be able to describe an appropriate evaluation of a patient presenting with chronic pain.
2. Be able to list treatment modalities for chronic malignant and nonmalignant pain syndromes.
3. Know common side effects of the pharmacologic agents used to treat chronic pain and list methods to overcome these side effects.

Considerations

This case represents a common primary care scenario of the management of a patient with chronic pain due to metastatic cancer. As treatment modalities for cancer improve, many people are living longer with cancer that would have been fatal in the past. Cancers can cause pain from direct invasion of organs or inflammation at the site of either the primary tumor or the metastases, with bony pain from metastatic disease being a common and especially painful complication. Some cancer treatments, such as surgery or radiation therapy, can be painful as well. Opioid analgesics are the mainstay of therapy for cancer pain, and there is little dispute or controversy regarding their use in this situation.

The management of chronic, nonmalignant pain syndromes can be much more challenging and controversial. Both physicians and patients may be concerned about the use of opioid therapy in these situations. The treatment of chronic, nonmalignant pain should be multidisciplinary and should utilize the biopsychosocial model of care to maximize outcomes. The use of pain medications is one option, with other modalities including exercise, physical rehabilitation, counseling, nonnarcotic medications, and complementary/alternative therapies as other viable options. The overall goals of chronic pain management should be to maximize function while minimizing pain and side effects of treatment.

Approach To:

Chronic Pain Management

DEFINITIONS

NEUROPATHIC PAIN: Pain caused by damage or dysfunction of a nerve or of the nervous system

MUSCLE PAIN: Local or regional pain involving soft tissue of the musculoskeletal system

INFLAMMATORY PAIN: Pain due to the release of inflammatory agents, such as prostaglandins, in response to illness, injury, or inflammation-causing condition (eg, rheumatoid arthritis)

MECHANICAL/COMP RESSIVE PAIN: Most commonly musculoskeletal pain aggravated by activity and improved by rest and limitation of physical activity

CLINICAL APPROACH

Assessment

Acute pain is pain associated with an illness or injury that has a generally accepted time course and progression-the pain starts with the onset of the illness/injury, the pain may be constant or intermittent, and the pain improves as the illness/ injury improves. In contrast, chronic pain is persistent pain that negatively impacts the person's quality of life and functioning. The pain can be constant, intermittent, or recurrent and may be associated with an illness or injury, but lasts longer than would be expected with the improvement of the condition.

Dealing with chronic pain can be frustrating for both the patient and the physician. Patients with chronic pain may have difficulties with personal and professional relationships due to their pain, may not be able to perform required or desired functions, and often do not get adequate pain relief. They can be accused of malingering, hypochondriasis, drug-seeking, and/ or drug addiction. Physicians can become frustrated at the inability to diagnose the cause of the pain and may order numerous and repeated expensive tests or procedures out of concern for the patient or fear of malpractice suits. Physicians may also struggle with concerns about being tricked into prescribing narcotic medications and the legal ramifications for inappropriate and excessive prescribing of controlled substances.

Numerous guidelines and recommendations for the management of chronic, nonmalignant pain are available. The overall goal of chronic pain management is to create a comprehensive plan utilizing the biopsychosocial model with a specific emphasis on managing pain, minimizing dependence, and improving function while limiting disability and side effects.

Initially, an assessment should be made to identify the type and cause of the pain through a thorough history and physical examination. The history should focus on the location, duration, intensity, and type of pain ( eg, neuropathic, musculoskeletal, etc). Time should be spent performing detailed psychological and social histories to evaluate for comorbid depression, other psychiatric conditions, or evidence of substance abuse. As it is legal for medicinal uses in many states, inquiring about marijuana use is paramount, as use of this drug may limit a clinician's ability to prescribe opioid-based therapy.

It is important to understand how the chronic pain condition has interfered with the patient's personal life, relationships, occupation, and other functioning. A detailed physical examination should be performed and documented at every visit. Functional assessment utilizing a standardized assessment tool should also be performed, as this allows for establishment of a baseline and provides for an objective assessment of improvement or deterioration over time. When available, previous medical records should be obtained and reviewed to avoid duplication of testing. If the history and examination suggest the presence of a treatable condition, and if the test has not previously been performed, then focused diagnostic testing should be performed. Some states have prescription audit registries that allow both state authorities and physicians to track and monitor controlled substance prescriptions that patients have been prescribed. Obtaining and reviewing such registries, where possible, should occur in all cases when a new patient presents to a practice for evaluation and treatment of chronic pain.

Nonpharmacologic Management

The comprehensive management of chronic pain should involve both pharmacologic and nonpharmacologic treatments. The patient, family, and physician should start by establishing realistic and achievable goals. The initial management should include nonpharmacologic therapies, including targeted exercise such as physical therapy or occupation-specific rehabilitation programs, psychological interventions such as counseling or cognitive behavioral therapy, and complementary or alternative modalities such as spinal and musculoskeletal manipulations, acupuncture, and meditation. Patient acceptance and participation are mandatory for success in reducing chronic pain. Unfortunately, third-party payers may not cover some of these treatment options and inability for patients to pay may limit access.

Pharmacologic Management

Initial pharmacologic management options should be based on the type, location, and severity of pain, the presence of comorbid conditions, and the need to minimize interactions with other medications that the patient may require. Nonnarcotic analgesics, such as acetaminophen or nonsteroidal anti-inflammatory drugs (NSAIDs), should be considered as first-line agents. However, these may not be viable options in the presence of significant liver (acetaminophen) or renal (NSAID) disease. Neuropathic pain may be relieved or reduced by the use of anticonvulsants (eg, gabapentin), and musculoskeletal pain may benefit from the judicious use of muscle relaxants. Antidepressant therapy (eg, selective serotonin reuptake inhibitors (SSRIs]) is also a beneficial adjunct to other therapies to help improve mood, sleep, and overall function. Benzodiazepines should be avoided in patients receiving chronic opioid analgesics to minimize the risk of oversedation and respiratory depression.

Opioid agonists (eg, hydrocodone, oxycodone, morphine, fentanyl) may be used for chronic, malignant, or nonmalignant pain when necessary in patients in whom pain cannot be controlled despite reasonable use of other modalities. In general, long-acting opioid agonists are preferred, as they provide greater duration of pain control and reduce the euphoria associated with short-acting opioid agonists, which may allow for improved patient function and less risk of abuse or addiction. The use of short-acting opioid agonists should be reserved for breakthrough pain. Common side effects of opioid agonists include sedation and constipation, a particularly bothersome issue for many patients. Follow-up of patients on chronic opioid therapy should include specific questioning about bowel movement frequency, and they should take daily stool softeners (eg, docusate) or stimulant/osmotic laxatives (eg, bisacodyl/polyethylene glycol 3350) to prevent chronic constipation.

Mixed opioid agonist-antagonists (eg, buprenorphine) act as partial agonists at one opioid receptor and antagonistic effects at another opioid receptor, and are becoming more viable options for patients with chronic pain. They provide a "ceiling effect" for analgesia, have the potential to induce acute abstinence in patients with physical dependency to agonist opioids, and are less preferred by patients who have opioid addiction. Tramadol, now considered a schedule 5 (V) drug by the Controlled Substances Act, is an opioid agonist with a mechanism of action that includes effects on monoamines including serotonin. It may be used as an adjunct for chronic pain, and carries a risk of lowering the seizure threshold.

Many physicians will encourage "controlled substance agreements" when their patients require long-term opioid analgesics. Such agreements provide guidelines for both physicians and patients regarding policies for use, follow-up visits, medication refills (eg, quantity of pills or patches, frequency of prescriptions, etc), and toxicology screening. These contracts may specify that the patient can only get controlled substance medications from one prescriber and one pharmacy. Typically, these agreements include the consent for urine toxicology screening as a mechanism to evaluate for drug diversion (eg, drug screen fails to show presence of the prescribed opioid in the urine) or unauthorized use of other drugs (eg, drug testing shows the presence of a nonprescribed or illicit drug). Agreements such as this, along with careful and thorough documentation in the medical record, can reduce physician concerns for legal issues regarding controlled substance prescriptions.

COMPREHENSION QUESTIONS

59.1 A 45-year-old diabetic patient presents for a routine follow-up. His diabetes has been uncontrolled although he is making good efforts to comply with his diet, exercise, and medication regimens. He has a long history of burning pain in his feet that has been uncontrolled by over-the-counter medications and is now worsening in severity such that he can no longer work. Your examination of his feet reveals no skin ulcerations, diminished but present and symmetrical pedal pulses, and reduced sensation on monofilament testing bilaterally. Along with aggressive management of his diabetes, which of the following interventions would be most appropriate at this time?

A. An NSAID

B. A long-acting opioid agonist

C. A short-acting opioid agonist

D. Gabapentin

E. Acupuncture

59.2 A 25-year-old patient who is a regular patient of the practice presents for an urgent evaluation. He has been receiving opioid analgesics from your practice for several months for back pain that was otherwise uncontrolled in spite of multidisciplinary treatments including physical therapy, chiropractic manipulation, and nonnarcotic medications. He has agreed to a controlled substance agreement that includes specification of the number of pills to be prescribed, frequency of refills, and urine toxicology screening. His last prescription was written by your practice partner last week.

The patient states that his prescription was stolen from his car this morning and he is very concerned that his pain will return if he doesn't get a new prescription right away. When you ask him to provide a urinalysis for a toxicology screen he states that he just urinated and can't wait until he urinates again, since he has to be somewhere in 15 minutes. Review of his chart indicates that he had one prescription rewritten earlier than agreed to in the recent past because he accidentally dropped his pills into the toilet. Which of the following is your best course of action at this time?

A. Refill his pain medication, with a warning that he needs to be more careful.

B. Refill his pain medication and refer him to an orthopedic surgeon for ongoing care.

C. Refuse to refill his pain medication, tell him it will be refilled on the appropriate date.

D. Refuse to refill his pain medication, refer him to Narcotics Anonymous.

E. Refuse to refill his pain medication, consider terminating him from your practice.

59.3 A 68-year-old man with prostate cancer metastatic to bone is going to be started on long-acting morphine for his pain. He denies depressed mood or insomnia. Which of the following adjunctive therapies should be considered along with long-term use of opioid agonists?

A. Bisacodyl

B. Trazodone

C. Tramadol

D. Gabapentin

E. Nortriptyline

ANSWERS

59.1 D. Diabetic neuropathy is the most common type of peripheral neuropathic pain. In many patients, it can be extremely painful and debilitating. Aggressive management of the patient's diabetes is extremely important, but improvement in neuropathic symptoms from diabetic control may take months and, in some patients, the neuropathy does not improve in spite of ideal diabetic control. An anticonvulsant, such as gabapentin, is often effective at alleviating or minimizing neuropathic pain. Antidepressants, especially tricyclic antidepressants, and NSAIDS, may also be effective. Physical therapy and acupuncture have no proven benefit in reducing symptoms of neuropathy. Opioid agonists are not indicated as first-line agents.

59.2 E. This patient is exhibiting several "red flags" for the misuse of narcotic medications. He is requesting refills more frequently than agreed and is refusing to provide urine for drug testing. Continuing to prescribe narcotic medications to the patient, even if waiting until an agreed upon date, would be inappropriate because of these concerns. While he may benefit from addiction counseling, he may not actually be using the medications himself-he could be giving them away or selling them to others. The most appropriate response provided would be to refuse this or any further, prescriptions and to terminate the patient from the practice.

59.3 A. Constipation is a common side effect of narcotic medication use. Establishing a bowel regimen for a patient who will be on a chronic narcotic program is an important adjunctive treatment. None of the other options are likely to be effective for chronic pain management due to metastatic disease to bone.

CLINICAL PEARLS

⯈ The management of chronic pain is best performed by using a multidisciplinary approach that utilizes the biopsychosocial model of care. Medications are only one aspect of this model.

⯈ Anticipate common side effects of your treatments, such as constipation associated with opioid agonists, and prophylactically provide your patient with the tools needed to address the problem .

⯈ Perform urine toxicology screening often in patients whom you suspect may be using other drugs or illicit substances including medical marijuana.

REFERENCES

American Academy of Pain Medicine. Use of opioids for the treatment of chronic pain. Available at: http:/ /www.painmed. org/ files/ use-of-opioids-for-the-treatment-of-chronic-pain.pdf. Accessed April 16, 2015. 

Camilleri M. Opioid-induced constipation: challenges and therapeutic opportunities. Am] Gastroenterol. 2011;106:835-842. 

Groninger H, Vijayan J. Pharmacologic management of pain at the end of life. Am Fam Physician. 2014;90(1):26-32. 

Jackman RP, Purvis JM, Mallett BS. Chronic nonmalignant pain in primary care. Am Fam Physician. 2008;78(10):1155-1162. 

Rockson SG. Current concepts and future directions in the diagnosis and management of lymphatic vascular disease. Vase Med. 2010;15(3):223-231. 

Schug SA, Goddard C. Recent advances in the pharmacological management of acute and chronic pain. Ann Palliate Med. 2014;3( 4):263-275. 

Smith H , Bruckenthal P. Implications of opioid analgesia for medically complicated patients. Drugs Aging. 2010;27(5):417-433. 

Trayes KP, Studdiford JS , Pickle S, Tully AS. Edema: diagnosis and management. Am Fam Physician. 2013;88(2):102-110. 

World Health Organization. WHO's pain relief ladder. Available at: http://www.who.int/cancer/palliative/ painladder/en/. Accessed April 16, 2015.

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