Secondary Logo

Journal Logo


Opioid management of pain: the impact of the prescription opioid abuse epidemic

Rauenzahn, Sherri; Del Fabbro, Egidio

Author Information
Current Opinion in Supportive and Palliative Care: September 2014 - Volume 8 - Issue 3 - p 273-278
doi: 10.1097/SPC.0000000000000065
  • Free



‘It's time we stop the source and treat the troubled’, CDC Director Dr Tom Frieden [1].

The increase in prescription opioid abuse has gathered attention from the medical societies, politicians, and the White House [2,3▪,4]. The number of opioid prescriptions increased by 60% over the last 10 years [5], and in 2012, 74% of prescription drug overdose deaths (14 800 deaths) were related to opioid analgesics [6]. According to the 2010 National Survey on Drug Use and Health, 5.1 million people were active nonmedical users of prescription opioids, 54% obtained them from a friend or relative for free, and 17% bought or took them [7▪▪]. When obtained from a friend or relative, the opioid had been prescribed by one physician 80% of the time [7▪▪].

Despite the perceived swing in the pendulum toward opioid overprescribing, a number of recent studies have reported undertreatment of pain in the setting of advanced illness and cancer [8–11]. There is also some concern that patients may suffer from underprescribing as an unintentional consequence of tighter regulations [12▪]. However, the alarming increase in the nonmedical use and opioid-related deaths demands that healthcare providers re-examine their prescribing practices in order to improve patient care and avert the introduction of excessive regulatory burden. In this review, we describe the clinical, pharmaceutical, financial, and regulatory impact of the opioid prescription abuse epidemic.

Box 1
Box 1:
no caption available


As a result of the subjective nature of pain, and its multidimensional construct comprising physical, psychological, social, and spiritual components, additional assessments are necessary for effective pain management. In light of the opioid abuse epidemic, an assessment of the patients risk for opioid misuse, monitoring for aberrant behavior, and doctor shopping are more important than ever to supplement patient-reported numeric pain scores.

Regional variation

In the USA, there are distinct regional variations in nonmedical opioid use. With the exception of several nonrural counties in Florida, increased nonmedical use and opioid-related deaths are found in states with large rural populations such as Kentucky, West Virginia, Alaska, and Oklahoma [13,14▪]. Possible factors contributing to greater rural misuse include increased sales and availability of opioid analgesics, economic deprivation, and tighter social networks [14▪]. Other purported causes for the national increase in opioid use include pharmaceutical marketing to physicians and consumers, and public misperception about the safety of prescription opioids [15]. There are other examples from the developed world of geographic variation. In an analysis of insurance system data for three different regions in France, both the amount and the type of opioid varied by region [16]. Poverty, unemployment, crime, and urbanization were associated with an increase in estimated opioid abuse as measured by a ‘doctor shopping’ index [16]. This heterogeneity among different populations suggests that interventions to ensure safe prescribing may need to be adapted depending on the regional differences in healthcare systems and the variability in patient's expectations of ‘effective’ pain management [14▪,17].

Universal precautions

Various adaptations [18–20] of the universal precautions [21] approach to pain management have been proposed for patients with cancer (Table 1). The goals of universal precautions are to maximize patient safety, pain management, and avoid opioid abuse or diversion. Included in universal precautions are assessment of risk factors, differential diagnoses, screening instruments, informed consent, opioid agreements, and longitudinal evaluations of function, compliance, and aberrant behavior. In an era of drug abuse, prescribing opioids based on the mantra of ‘pain is what the patient says it is’ seems ill-considered. The high prevalence of chemical coping, depression, somatization, concerns about opioid diversion, and the risk of opioid overdose necessitates a more comprehensive patient assessment in order to avoid unnecessary opioid dose escalation [22].

Table 1
Table 1:
Managing opioid risk and chemical coping in patients with cancer based on universal precautions

Screening tools for risk assessment and additional ‘objective’ measures such as prescription monitoring programs (PMPs) may help to distinguish patients who are chemically coping, suffering from pseudo addiction, or diverting their medication for nonmedical use. Chemical coping and pseudoaddiction patients present with similar behaviors and pose a treatment dilemma for the physician as they require different management strategies [23]. Chemical copers use opioids in nonprescribed ways to deal with the stress associated with their diagnosis. These patients require a multidimensional interdisciplinary approach and co-management with substance abuse specialists when their chemical coping is at the maladaptive addiction end of the spectrum. In contrast, patients with pseudoaddiction [24] require appropriate increases in pain medications.

Re-assessment of patients and their opioid needs periodically are essential. For example, patients who no longer have evidence of disease but suffer from chronic pain should be managed with scheduled opioids and not as needed immediate-release opioids. Also, because of the concurrent, albeit more modest rise in benzodiazepine misuse, providers will need to monitor patients for additive side-effects that are consistent with combination opioids and benzodiazepines [25] such as severe sedation, cognitive dysfunction, and delirium. The increased risk of death especially when opioids are prescribed at higher doses or in combination with other substances has clearly emerged [26–28], even in patients with cancer. Unfortunately, none of the universal precautions strategies to avoid abuse is fail-safe. For example, although pill counts are recommended as a simple way to monitor misuse and ensure compliance [29], a recent report describes the use of pill renting to avoid the detection of misuse [30].

Risk assessment

The high prevalence of alcoholism [31] and other risk factors such as a family history of abuse and psychiatric disorders suggests that all patients with cancer should undergo a risk assessment when they are started on opioids [32]. Patients identified as high risk will require closer monitoring and greater utilization of clinical resources, such as the interdisciplinary team. Commonly used tools include the opioid risk tool (ORT), CAGE-AID, and screener and opioid assessment for patients with pain-revised (SOAPP-R). For widespread adoption, these tools will need to be brief and easily administered. Currently the CAGE, ORT, and screener and opioid assessment for patients with pain-short form, (SOAPP-SF ) [33] take less than 5 min to complete and can be self-administered. Almost one in five patients with advanced cancer are identified as having a ‘positive’ CAGE score for alcoholism [34], and in patients receiving chemoradiation for head and neck cancer, a positive CAGE score is a risk factor for prolonged opioid use after completion of radiation therapy [35].

Urine drug screening

A systematic review found relatively weak evidence for the efficacy of written opioid agreements and urine drug testing in reducing opioid misuse by patients with chronic nonmalignant pain [36]. A more recent observational study found the addition of ‘objective’ data [urine drug screening (UDS) and prescription monitoring] improved the identification of patients at higher risk of opioid abuse or diversion [37]. Although there are very few studies in patients with cancer-related pain, the use of UDS is likely to increase in palliative care patients. A retrospective chart review of patients with cancer showed that moderate-to-high risk stratification using a screening tool (ORT) strongly predicted abnormal urine drug screen results [38]. As UDS utilization increases, clinicians need to become familiar with the interpretation of abnormal results and their management [39]. In the vulnerable palliative care population that is often burdened by multiple stressors, it is especially important to avoid false accusations of opioid misuse and diversion.

Prescription monitoring programs and doctor shopping

The practice of doctor shopping for opioids has increased over the last decade [40,41]. Healthcare information systems such as electronic prescriptions and PMPs attempt to minimize the information gaps between providers. A 2013 survey of practitioners using electronic prescribing of controlled substances found a perceived reduction of medication errors, altered prescriptions, and lost prescriptions [42]. Although electronic prescribing was found to be less burdensome than expected, the limited adoption by clinical practices and pharmacies attenuates this system's ability to improve patient's safety and decrease diversion [42]. In an analysis of 146 million opioid prescriptions dispensed in 2008, 0.7% of patients presumed to be doctor shoppers, on average, obtained 32 opioid prescriptions from 10 different prescribers [43]. Although these patients cannot be identified with absolute certainty as ‘doctor shoppers’, their care can be characterized as dangerously uncoordinated [43]. Providers are now able to access PMPs in 46 individual states; however, the majority of physicians do not access this information. Surveys show physicians and pharmacists are more likely to use PMPs to detect abuse, diversion, or doctor shopping if the PMP is electronic and easily accessible [44,45]. Unfortunately, pharmacists using the PMP were no more likely to refer the patient back to the prescriber, contact the provider, or refuse to fill the prescription [45]. Additionally, as of 2008, there was no significant effect on the morphine milligram equivalents per capita dispensed in states with PMP [46▪]. This discrepancy between design and practice highlights the need for improved training on the interpretation and management of suspicious PMP findings. Although some have recommended mandates or regulations requiring the review of PMP prior to prescribing, this may discourage the general practitioners from prescribing controlled substances [15].


As a result of the misuse of commonly prescribed opioids, the pharmaceutical industry is pursuing tamper-proof formulations. In a preliminary, industry-supported study, rates of abuse, therapeutic errors, and diversion fell for brand extended-release oxycodone after the introduction of a reformulated extended-release oxycodone [47,48]. Also, in a move to combat the increase in overdose deaths, the Food and Drug Administration approved a hand-held injector device in 2014 that would allow family members or caregivers to administer naloxone outside of a healthcare setting [49]. Finally, cost should be considered when prescribing any specific formulation of opioid. In an executive summary costing report by the UK's National Institute for Health and Clinical Excellence (NICE), the implementation of oral immediate or sustained release formulations first line, rather than transdermal opioids, was likely to generate the largest savings [50]. Because newer tamper-proof opioids are likely to further increase the costs to patients and health systems, these formulations should be prescribed based on the individual risk assessment.


Hydrocodone is the single most commonly prescribed medication in the USA, followed by levothyroxine, simvastatin, and lisinopril [51]. From 2007 to 2011, spending on opioids increased by US$1.6 billion, and opioid analgesics were the third most prescribed therapeutic class behind antidepressants and lipid regulator drugs. A literature review [52] of the economic burden associated with opioid abuse found estimates of US$8.6 billion per year for workplace, healthcare, and criminal justice expenditures. A more recent estimate from 2007 increased the total societal cost to US$55.7 billion [53].

Increased laboratory testing

The healthcare costs associated with increased urine drug screens may be significant and their justification will require additional research showing improved clinical outcomes or lower health utilization. Except for individual authors and institutions [54], there are no recommendations or guidelines from the oncological or palliative care organizations regarding UDS.

Increased healthcare utilization

Patients who misuse opioids have significantly higher healthcare utilization and costs [55]. Data from the national epidemiologic survey on alcohol and related conditions suggest that the nonmedical use of opioids may increase the risk for alcohol use disorder, depression, bipolar, and anxiety disorders [56]. In a separate study reviewing claims data, patients identified with potentially problematic opioid use had significantly more office visits (3.7 vs. 2.4), inpatient admissions (0.9 vs. 0.4), higher outpatient costs (US$10 055 vs. US$7358), and total healthcare costs (US$38 553 vs. US$26 193) than controls [55]. For every unintentional overdose death (14 800 deaths) in 2008, 9 patients (133 200 patients) were admitted for substance abuse treatment, there were 35 related emergency room visits (518 000 visits), 161 people (2.4 million people) reported drug abuse or dependence, and 461 people (∼6.8 million people) reported the nonmedical use of opioids [57].


Amidst a global emphasis on the palliative care, worldwide opioid consumption has not increased proportionately in low-to-middle income countries [58], secondary to formulary limitations and regulatory restrictions [59]. Although formulary limitations may be perceived as a viable pathway for ensuring public safety, adequate pain control may be markedly compromised [58]. Developing nations especially may be impacted by the current concerns about opioid prescription abuse as most lack access to necessary opioid analgesics and are burdened by regulatory barriers.


In an effort to improve both physician and patient education regarding pain management, the federal government implemented the opioid risk evaluation and mitigation strategies (REMS). Although physicians recognize that these programs assist in ensuring safe use, most also report concern for increased burden on clinical practice, with little impact on patient outcome [60]. Additionally, there is some effort directed toward pill repositories or returns to prevent open access to opioids [61]. Initiatives by the DEA such as The National Prescription Drug Take-Back Day [62] aim to provide a safe, convenient means of disposing prescription drugs, while also educating the general public about the potential for abuse of medications.


Given the emphasis the Joint Commission and the Federation of State Medical Boards (FSMBs) have placed on the patient's right for pain relief [12▪,57] over the last decade, physicians may have concerns about underprescribing opioids. Unfortunately, the importance placed on the patient's expression of pain has not been coupled with other crucial clinical considerations such as substance abuse risk.

Law enforcement

In a recent survey of pain clinic patients, 45% noted at least one episode of diversion (defined as lost, stolen, shared, or sold). The same study found a higher likelihood of diversion with a family history of drug abuse or history of criminal behavior [63]. A unique statewide North Carolina law enforcement group dedicated to investigating criminal violations involving prescription drugs noted a 400% increase in diversion investigations in a 5-year period and a 300% increase in overdose deaths being investigated as homicide or manslaughter. In a 2-year period, investigations involving healthcare professionals increased 35% [61]. Similar concerning behavior among healthcare workers has prompted the healthcare systems and academic institutions to implement drug diversion prevention initiatives [64].


The opioid prescription abuse epidemic demands that physicians, including those managing patients with cancer-related pain, prescribe opioids based on a comprehensive patient assessment. Implementing universal precautions that include informed consent, an assessment of risk factors for abuse, increased vigilance and structure for those at risk, and a periodic re-assessment of patient and tumor related factors causing pain are essential to providing optimal clinical care. Additionally, provider and patient education, prescription monitoring, and regulations that do not impede appropriate access to opioids are most likely to improve both pain management and public safety.



Conflicts of interest

E.D.F. and S.R. have no conflicts of interest to declare.


Papers of particular interest, published within the annual period of review, have been highlighted as:

  • ▪ of special interest
  • ▪▪ of outstanding interest


1. Centers for Disease Control and Prevention. Available at [Accessed 18 April 2014]
2. Ochoa G. Pain medicine news – Senate Finance Committee investigates rise in prescription opioid use. Pain Med News; 2012. Available at
3▪. Kirschner N, Ginsburg J, Sulmasy LS. Prescription drug abuse: executive summary of a policy position paper from the American College of Physicians. Ann Intern Med 2014; 160:198–200.

This study provides guidance to the prescribers and policymakers regarding the measures to address the problem of prescription drug abuse.

4. Prescription Drug Abuse. The White House. Available at
5. National Institute on Drug Abuse Research Report Series – prescription drugs: abuse and addiction. 2011. Available at [Accessed 18 April 2014]
6. Vital signs: overdoses of prescription opioid pain relievers – United States, 1999–2008. MMWR Morbid Mortal Wkly Rep 2011.
7▪▪. Results from the 2011 NSDUH: Summary of National Findings, SAMHSA, CBHSQ. Available at [Accessed 18 April 2014]

An annual survey of illicit drugs, alcohol, and tobacco use in over 67 000 noninstitutionalized people in the United States sponsored by the Substance Abuse and Mental Health Services Administration (SAMHSA). The survey highlights the growth in the nonmedical use of opioid analgesics and their source.

8. Apolone G, Corli O, Caraceni A, et al. Pattern and quality of care of cancer pain management. Results from the Cancer Pain Outcome Research Study Group. Br J Cancer 2009; 100:1566–1574.
9. Te Boveldt N, Vernooij-Dassen M, Burger N, et al. Pain and its interference with daily activities in medical oncology outpatients. Pain Physician 2013; 16:379–389.
10. Fisch MJ, Lee J, Weiss JW, et al. Prospective, observational study of pain and analgesic prescribing in medical oncology outpatients with breast, colorectal, lung, or prostate cancer. J Clin Oncol 2012; 30:1980–1988.
11. Deandrea S, Montanari M, Moja L, Apolone G. Prevalence of undertreatment in cancer pain. A review of published literature. Ann Oncol 2008; 19:1985–1991.
12▪. Garcia AM. State laws regulating prescribing of controlled substances: balancing the public health problems of chronic pain and prescription painkiller abuse and overdose. J Law Med Ethics J Am Soc Law Med Ethics 2013; 41 (Suppl. 1):42–45.

A concise review of the State Laws regulating opioid prescriptions and the factors influencing prescription abuse.

13. McDonald DC, Carlson K, Izrael D. Geographic variation in opioid prescribing in the U.S. J Pain 2012; 13:988–996.
14▪. Keyes KM, Cerdá M, Brady JE, et al. Understanding the rural–urban differences in nonmedical prescription opioid use and abuse in the United States. Am J Public Health 2014; 104:e52–e59.

An evaluation of the factors contributing to the geographic variation in opioid prescription abuse.

15. Schreiner MD. A deadly combination: the legal response to America's prescription drug epidemic. J Leg Med 2012; 33:529–539.
16. Nordmann S, Pradel V, Lapeyre-Mestre M, et al. Doctor shopping reveals geographical variations in opioid abuse. Pain Physician 2013; 16:89–100.
17. Fischer B, Keates A, Bühringer G, et al. Nonmedical use of prescription opioids and prescription opioid-related harms: why so markedly higher in North America compared to the rest of the world? Prescription opioid problems – why highest in North America? Addiction 2014; 109:177–181.
18. Koyyalagunta D, Burton AW, Toro MP, et al. Opioid abuse in cancer pain: report of two cases and presentation of an algorithm of multidisciplinary care. Pain Physician 2011; 14:E361–E371.
19. Modesto-Lowe V, Girard L, Chaplin M. Cancer pain in the opioid-addicted patient: can we treat it right? J Opioid Manag 2012; 8:167–175.
20. Del Fabbro E. Assessment and management of chemical coping in patients with cancer. J Clin Oncol 2014; DOI 10.1200/JCO.2013.52.5170
21. Gourlay DL, Heit HA, Almahrezi A. Universal precautions in pain medicine: a rational approach to the treatment of chronic pain. Pain Med Malden Mass 2005; 6:107–112.
22. Bruera E, Schoeller T, Wenk R, et al. A prospective multicenter assessment of the Edmonton staging system for cancer pain. J Pain Symptom Manage 1995; 10:348–355.
23. Kwon JH, Tanco K, Hui D, et al. Chemical coping versus pseudoaddiction in patients with cancer pain. Palliat Support Care 2014; 1–5.[Epub ahead of print].
24. Passik SD, Kirsh KL, Webster L. Pseudoaddiction revisited: a commentary on clinical and historical considerations. Pain Manag 2011; 1:239–248.
25. Jones JD, Mogali S, Comer SD. Polydrug abuse: a review of opioid and benzodiazepine combination use. Drug Alcohol Depend 2012; 125:8–18.
26. Boyer EW. Management of opioid analgesic overdose. N Engl J Med 2012; 367:146–155.
27. Kripke DF, Langer RD, Kline LE. Hypnotics’ association with mortality or cancer: a matched cohort study. BMJ Open 2012; 2:e000850.
28. Bohnert AS, Valenstein M, Bair MJ, et al. Association between opioid prescribing patterns and opioid overdose-related deaths. JAMA 2011; 305:1315–1321.
29. Foxhall K. Opioid abuse potential prompts monitoring role for internists. ACP Internist 2011; Available at [Accessed 18 April 2014].
30. Viscomi CM, Covington M, Christenson C. Pill counts and pill rental: unintended entrepreneurial opportunities. Clin J Pain 2013; 29:623–624.
31. Martin MJ, Heymann C, Neumann T, et al. Preoperative evaluation of chronic alcoholics assessed for surgery of the upper digestive tract. Alcohol Clin Exp Res 2002; 26:836–840.
32. Tragesser SL, Jones RE, Robinson, et al. Borderline personality disorder features and risk for prescription opioid use disorders. J Personal Disord 2013; 27:427–441.
33. Koyyalagunta D, Bruera E, Aigner C, et al. Risk stratification of opioid misuse among patients with cancer pain using the SOAPP-SF. Pain Med Malden Mass 2013; 14:667–675.
34. Dev R, Parsons HA, Palla S, et al. Undocumented alcoholism and its correlation with tobacco and illegal drug use in advanced cancer patients. Cancer 2011; 117:4551–4556.
35. Kwon JH, Hui D, Chisholm G, Bruera E. Predictors of long-term opioid treatment among patients who receive chemoradiation for head and neck cancer. Oncologist 2013; 18:768–774.
36. Starrels JL, Becker WC, Alford DP, et al. Systematic review: treatment agreements and urine drug testing to reduce opioid misuse in patients with chronic pain. Ann Intern Med 2010; 152:712–720.
37. Hamill-Ruth RJ, Larriviere K, McMasters MG. Addition of objective data to identify risk for medication misuse and abuse: the inconsistency score. Pain Med 2013; 14:1900–1907.
38. Barclay JS, Owens JE, Blackhall LJ. Screening for substance abuse risk in cancer patients using the opioid risk tool and urine drug screen. Support Care Cancer 2014; [Epub ahead of print].
39. Turner JA, Saunders K, Shortreed SM, et al. Chronic opioid therapy risk reduction initiative: impact on urine drug testing rates and results. J Gen Intern Med 2013; 29:305–311.
40. McCabe SE, West BT, Boyd CJ. Leftover prescription opioids and nonmedical use among high school seniors: a multi-cohort national study. J Adolesc Health 2013; 52:480–485.
41. 2013; Lewis ET, Cucciare MA, Trafton JA. What do patients do with unused opioid medications? JT Clin J Pain. [Epub ahead of print].
42. Thomas CP, Kim M, Kelleher SJ, et al. Early experience with electronic prescribing of controlled substances in a community setting. J Am Med Inform Assoc 2013; 20:e44–e51.
43. McDonald DC, Carlson KE. Estimating the prevalence of opioid diversion by ‘Doctor Shoppers’ in the United States. PLoS One 2013; 8:e69241.
44. Green TC, Mann MR, Bowman SE, et al. How does use of a prescription monitoring program change medical practice? Pain Med 2012; 13:1314–1323.
45. Green TC, Mann MR, Bowman SE, et al. How does use of a prescription monitoring program change pharmacy practice? J Am Pharm Assoc 2013; 53:273.
46▪. Brady J, Wunsch H, Dimaggio C, et al. Prescription drug monitoring and dispensing of prescription opioids. Public Health Rep 2014; 129:139–147.

Implementation of the state prescription monitoring programs did not show a significant impact on per-capita opioids dispensed.

47. Severtson SG, Bartelson BB, Davis JM, et al. Reduced abuse, therapeutic errors, and diversion following reformulation of extended-release oxycodone in 2010. J Pain 2013; 14:1122–1130.
48. Lourenço LM, Matthews M, Jamison RN. Abuse-deterrent and tamper-resistant opioids: how valuable are novel formulations in thwarting nonmedical use? Expert Opin Drug Deliv 2013; 10:229–240.
49. Press Announcements – FDA approves new hand-held auto-injector to reverse opioid overdose. Available at
50. Opioids in palliative care: costing report – implementing NICE guidance. 2012. Available at [Accessed 18 April 2014]
51. The use of medicines in the United States: review of 2011. 2012. Available at [Accessed 18 April 2014]
52. Strassels SA. Economic burden of prescription opioid misuse and abuse. J Manag Care Pharm 2009; 15:556–562.
53. Birnbaum HG, White AG, Schiller M, et al. Societal costs of prescription opioid abuse, dependence, and misuse in the United States. Pain Med Malden Mass 2011; 12:657–667.
54. Anghelescu DL, Ehrentraut JH, Faughnan LG. Opioid misuse and abuse: risk assessment and management in patients with cancer pain. J Natl Compr Canc Netw 2013; 11:1023–1031.
55. Tkacz J, Pesa J, Vo L, et al. Opioid analgesic-treated chronic pain patients at risk for problematic use. Am J Manag Care 2013; 19:871–880.
56. Schepis TS, Hakes JK. Dose-related effects for the precipitation of psychopathology by opioid or tranquilizer/sedative nonmedical prescription use: results from the national epidemiologic survey on alcohol and related conditions. J Addict Med 2013; 7:39–44.
57. Manchikanti L, Helm S 2nd, Fellows B, et al. Opioid epidemic in the United States. Pain Physician 2012; 15 (Suppl 3):ES9–ES38.
58. Atasoy A, Bogdanovic G, Aladashvili A, et al. An international survey of practice patterns and difficulties in cancer pain management in Southeastern Europe: a Turkish & Balkan Oncology Group common initiative. J BUON 2013; 18:1082–1087.
59. Cleary J, Radbruch L, Torode J, Cherny NI. Next steps in access and availability of opioids for the treatment of cancer pain: reaching the tipping point? Ann Oncol 2013; 24:xi60–xi64.
60. Salinas G, Robinson CO, Abdolrasulnia M. Primary care physician attitudes and perceptions of the impact of FDA-proposed REMS policy on prescription of extended-release and long-acting opioids. J Pain Res 2012; 5:363–369.
61. Varnell DR. Prescription drug diversion: a law enforcement perspective. N C Med J 2013; 74:246.
62. Drug disposal information – national take-back initiative. Available at [Accessed 18 April 2014]
63. Walker MJ, Webster LR. Risk factors for drug diversion in a pain clinic patient population. J Opioid Manag 2012; 8:351–362.
64. Kiser K. Diversion detective. Minn Med 2013. [Accessed 18 April 2014]

cancer pain; management of chemical coping; opioid abuse epidemic

© 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins