Pain Management: The Pharmacist's Evolving Role

Pharmacists can help minimize risk for patients using pain medications.

There are currently more than 100 million Americans suffering from chronic pain, including 65% to 80% of terminal cancer patients, 62% of nursing home residents, and many others who must combat pain on a daily basis.¹ Chronic pain afflicts more patients in the United States than diabetes, coronary heart disease, stroke, and cancer combined.^2-4 It reduces a patient’s independence and ability to perform many daily activities and puts a strain on social relationships, mood, and sleep patterns.

This decrease in overall functioning places a burden on the national economy, with total annual costs of health care and lost productivity attributable to pain ranging from $560 billion to $635 billion (2010 dollars) in the United States.¹ With the number of patients suffering from pain increasing as the US population ages, the demand for pain management pharmacists will continue to rise.

Types of Pain

The most widely accepted definition of pain is “an unpleasant sensory and emotional experience that is associated with actual or potential tissue damage or described in such terms.”⁵ There are, however, as many different definitions of pain as there are ways that pain can manifest itself in complex patients. Each directly influences the course of therapy for each individual.

Pain is classified by its duration and etiology. Duration of pain is classified in 2 categories: acute pain and chronic pain. Acute pain is a response to injury or tissue damage that generally does not last longer than it takes for normal healing to occur. Typically, this pain lasts less than 6 months, but may become chronic if not adequately treated. Chronic pain, on the other hand, persists longer than the normal course of time associated with injury, typically more than 3 to 6 months. In many cases, the initial injury may not be readily identifiable.

There are several etiologies of pain, including nociceptive pain and neuropathic pain. Nociceptive pain includes somatic pain, which arises from injury to body tissues and tends to be localized but varies in description and experience. Visceral pain is a nociceptive pain arising from the viscera mediated by stretch receptors; it is poorly localized, deep, dull, and cramping.⁶ Neuropathic pain manifests itself in abnormal neural activity secondary to disease, injury, or dysfunction of the nervous system. This type of pain can arise from the peripheral nervous system or the central nervous system.⁷

Pain varies greatly in duration and etiology and often progresses or regresses as the pathology of the patient’s injury or disease state changes. In many cases, especially in chronic pain patients, complex pain states do not exist as a single well-defined pain, but rather as a mix of several types of pain.

The Use of Medication to Treat Pain

There are many medications used to treat the various etiologies of pain. To maximize efficacy and minimize risk, therapies should be individualized for each patient’s pathology. The goal of proper pain management should always be to improve the patient’s quality of life, decrease the average pain rating, and improve overall functioning. Pharmacists must do their best to minimize patient risk associated with pain management. Proper medication therapy can reduce addiction, short- and long-term adverse effects, and risk of overdose.

For patients suffering from neuropathic pain including, but not limited to, peripheral neuropathic pain (eg, diabetic neuropathy, radiculopathy, postherpetic neuralgia) and central neuropathic pain (eg, post stroke pain, Parkinson’s disease pain, spinal cord injury pain, HIV myelopathy), there are many potential appropriate treatment options. These medications include tricyclic antidepressants, anticonvulsants, gabapentin, pregabalin, selective serotonin reuptake inhibitors, N-methyl-D-aspartate antagonists, topical lidocaine and capsaicin, opioid analgesics, and tramadol. It is the pharmacist’s responsibility to evaluate these medications. Pharmacists play a pivotal role in determining drug efficacy and in monitoring the side effects and interactions of multiple medications to help patients achieve good therapeutic outcomes.

When patients suffer from nociceptive pain, including somatic and visceral pain, certain classes of medications tend to have higher efficacy. These nociceptive pain medications include acetaminophen, nonsteroidal anti-inflammatory drugs, topical lidocaine, capsaicin, corticosteroids, skeletal muscle relaxants, opioid analgesics, and tramadol. Patients taking these medications need to be closely monitored by the pharmacist to ensure both dose and agent are appropriate for the patient’s comorbidities, age, and other possible medication interactions.

It is crucial that the pharmacist always perform a quick equianalgesic calculation to ensure that a patient’s new opioid medication is at a safe and effective dose (Online Table 1). When using the equianalgesic chart, an incomplete cross-tolerance dose reduction of 25% to 50% may be appropriate.

Table 1: Equianalgesic Table¹¹

Opioid

IV (mg)

Oral (mg)

Morphine

10

30

Hydrocodone

----

30

Oxycodone

10

20

Oxymorphone

1

10

Hydromorphone

1.5

7.5

Codeine

100

200

^{IV = intravenous.}

Pharmacist involvement can especially affect outcomes in pain management for patients with multiple disease states taking multiple medications for multiple types of pain. The incidence of adverse medication events is reduced with pharmacist intervention.

The Role of the Pharmacist

Nobody deserves to live with severe pain. Pharmacists can help patients live meaningful and productive lives with adequately managed pain. It is the responsibility of pharmacists to monitor patients’ 4 As: analgesia, activities of daily living, adverse events, and aberrant drug behaviors.⁸ Proper pain assessment is essential for understanding patients’ pain and providing highly effective treatment while simultaneously minimizing risk.

Assessment and proper planning can also help minimize patient risk. This can start with “The 10 Steps of Universal Precautions in Pain Medicine” (Online Table 2). By applying these recommendations, stigma is reduced and overall outcomes are improved.⁹

Table 2: The 10 Universal Precautions in Pain Medicine⁹

• Make diagnosis with a differential
• Conduct psychological assessment, screening for addiction potential
• Obtain informed consent
• Utilize a treatment agreement
• Conduct pre- and post intervention assessment of pain level and function
• Conduct an appropriate trial of opioid therapy with or without adjuvants
• 7. Conduct reassessment of pain score and level of function
• Regularly assess “the 4 A’s of pain”
• Periodically review all comorbid conditions
• Document evaluations and follow-up appointments

Pharmacists: Making a Difference in Pain Management

In a 340-bed community hospital in Santa Monica, California, a pain management pharmacist was hired and involved in managing patients on patient-controlled analgesia. In the 12-month period from August 2006 to July 2007, the cost savings associated with earlier discharges were estimated at $97,200.¹² Now, the pharmacy department is in charge of comfort care protocol for dying patients, palliative care services, and topical medication policy. The pharmacy team is also responsible for education and drug diversion monitoring.

The frontline pharmacist published an article on the implementation of a pain management program where pharmacists are involved in providing pain medication reconciliation on admission, prescription medication management, and recommending pain management regimens for patients with complex profiles. The findings from the frontline pharmacist over 1 year and 2499 patients 44% required an intervention related to patients’ histories that were being used to make inpatient medication decisions.¹³

There are many additional studies showing the benefits of pharmacist involvement in pain management. The Joint Commission’s Sentinel Event database (2004-2011) indicates that 47% of opioid-related adverse drug events in hospitals that caused harm to patients, including death, were wrong dose medication errors.¹⁴

Pharmacy-directed pain management is not without its implementation challenges. With the many complex variables of pain management, having a pharmacist involved in the process of therapeutic decisions can save both lives and money while improving quality of life for patients.

Jerry Barbee, Jr, PharmD, BCPS, is a clinical pharmacist at HCA West Florida Hospital. Jaclyn Chessher, PharmD, is a clinical pharmacist at HCA West Florida Hospital. Max Greenlee is a 2016 PharmD candidate at the University of Florida.

References

• Institute of Medicine. Summary. In: Relieving Pain in America: A Blueprint for Transforming Prevention, Care, Education, and Research. Washington, DC: The National Academies Press; 2011:1-18.
• Statistics about diabetes. American Diabetes Association website. www.diabetes.org/diabetes-basics/diabetes-statistics/. Updated May, 18, 2015.
• Roger VL, Go AS, Lloyd-Jones DM, et al; American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Heart disease and stroke statistics—2011 update: a report from the American Heart Association. Circulation. 2011;123(4):e18-e209. doi: 10.1161/CIR.0b013e3182009701.
• American Cancer Society. Cancer prevalence: how many people have cancer? American Cancer Society website. www.cancer.org/cancer/cancerbasics/cancer-prevalence. Updated May 20, 2014.
• Gebhart GF. Scientific Issues of Pain and Distress. In: Definition of Pain and Distress and Reporting Requirements for Laboratory Animals: Proceedings of the Workshop Held June 22, 2000. Washington, DC: National Academies Press; 2000.
• Institute for Clinical Systems Improvement. Assessment and Management of Chronic Pain. 4th ed. Bloomington, MN: Institute for Clinical Systems Improvement; November 2009.
• Bennett M. The LANSS Pain Scale: the Leeds assessment of neuropathic symptoms and signs. Pain. 2001;92(1-2):147-157.
• Passik SD, Kirsh KL, Whitcomb L, et al. Monitoring outcomes during long-term opioid therapy for noncancer pain: results with the Pain Assessment and Documentation Tool. J Opioid Manag. 2005;1(5):257-266.
• Gourlay DL, Heit HA, Almahrezi A. Universal precautions in pain medicine: a rational approach to the treatment of chronic pain. Pain Med. 2005;6(2):107-112.
• O'Connor AB, Dworkin RH. Treatment of neuropathic pain: an overview of recent guidelines. Am J Med. 2009;122(suppl 10):S22-S32. doi: 10.1016/j.amjmed.2009.04.007.
• McPherson ML. Demystifying Opioid Conversion Calculations: A Guide for Effective Dosing. Bethesda, MD: American Society of Health-System Pharmacists; 2009.
• Fan T, Elgourt T. Pain management pharmacy service in a community hospital. Am J Health Syst Pharm. 2008;65(16):1560-1565. doi: 10.2146/ajhp070597.
• Ghafoor VL, Phelps P, Pasto J. Implementation of a pain medication stewardship program. Am J Health Syst Pharm. 2013;70(23):2070-2075. doi: 10.2146/ajhp120751.
• The Joint Commission. Safe use of opioids in hospitals. The Joint Commission website. www.jointcommission.org/assets/1/18/SEA_49_opioids_8_2_12_final.pdf.