Opioid rotation: the science and the limitations of the equianalgesic dose table

Opioid rotation in clinical practice

INTRODUCTION

Although chronic opioid therapy is usually initiated using short-acting opioids, many patients with chronic pain are subsequently converted to long-acting and extended-release preparations. In clinical practice, optimal management requires careful individualization of dosage in order to achieve an appropriate balance of efficacy and adverse effects. After successful initiation and stabilization of opioid treatment, subsequent changes in regimen may still be required to maintain efficacy with an acceptable adverse effect profile.

METHODS

This is a qualitative review of the available literature from June 2012 or earlier on opioid rotation for the management of chronic pain in the clinical setting. The PubMed database was searched using various search terms, and additional articles were identified through manual search of the bibliographies of articles identified through the PubMed search. Papers were selected based on relevance to the topic.

RESULTS

When considering opioid rotation, clinicians must take into account not only the significant differences in potency among opioid drugs but also the considerable interpatient variability in response to opioids. The estimate of relative potency used in calculating an appropriate starting dose when switching from one opioid to another has been codified on equianalgesic dose tables. To reduce the risk of unintentional overdose, a two-step calculation has been proposed, which incorporates an initial reduction (typically 25-50%) in the equianalgesic dose followed by a second evaluation based on the severity of pain at the time of rotation along with other medical or psychosocial factors that might alter the effectiveness and tolerability of the new drug. Given the uncertainty of accurately predicting a patient's response to treatment, each initial exposure to a new opioid should be considered a discrete clinical trial to assess the degree of response. Systematic reviews of opioid rotation have documented the re-establishment of adequate pain control or reduced adverse effects in 50-80% of patients.

CONCLUSIONS

Although continued research is needed to refine equianalgesic doses further, opioid rotation is an important and necessary practice in patients with chronic cancer or noncancer pain that is refractory to the initially used opioid.

Predictors of postoperative movement and resting pain following total knee replacement

This study determined preoperative predictors of movement and resting pain following total knee replacement (TKR). We hypothesized that younger patients with higher preoperative pain intensity, pain sensitivity, trait anxiety, pain catastrophizing, and depression would be more likely to experience higher postoperative movement pain than older patients with lower scores on these variables prior to surgery, and that predictors would be similar for resting pain. Demographics, analgesic intake, anxiety, depression, pain catastrophizing, resting pain, movement pain (ie, during active knee range of motion), and quantitative sensory tests were performed preoperatively on 215 participants scheduled for a unilateral TKR. On postoperative day 2, analgesic intake, resting pain, and movement pain were again assessed. Significant predictors of moderate or severe movement pain were higher preoperative movement pain, von Frey pain intensity, and heat pain threshold. People with severe movement pain preoperatively were 20 times more likely to have severe movement pain postoperatively. When the influence of preoperative movement pain was removed, depression became a predictor. Significant predictors of moderate to severe resting pain were higher preoperative resting pain, depression, and younger age. These results suggest that patients with higher preoperative pain and depression are more likely to have higher pain following TKR, and younger patients may have higher resting pain. Cutaneous pain sensitivity predicted movement pain but not resting pain, suggesting that mechanisms underlying movement pain are different from resting pain. Aggressive management of preoperative pain, pain sensitivity, and depression prior to surgery may facilitate postoperative recovery.

[Cancer pain in palliative medicine]

During the course of cancer progression up to 90% of the patients suffer from pain of nociceptive, neuropathic or mixed nociceptive/neuropathic origin. Psychological, social or existential factors may additionally affect the intensity of pain (concept of "total pain"). The WHO "analgesic ladder" provides a large variety of effective drugs that can be used according to the specific pain type. Parenteral or peridural opioid therapy as well as neurodestructive methods can effectively support the analgesic treatment in selected cases.

Dynamic risk factors in the misuse of opioid analgesics

OBJECTIVE

Identify the risk factors for prescription opioid misuse among patients taking prescription opioids to deal with chronic pain.

METHODS

We examined the literature for a variety of dynamic risk factors associated with opioid misuse among the chronic pain population in order to present a narrative review. Considered were: taking single or multiple opioids, pain intensity, mental health disorders, including a history of preadolescent sexual abuse, personal and familial history of substance abuse, a history of legal problems, being a crime victim, drug-seeking behaviors, drug craving, and age.

RESULTS

A variety of risk factors have been studied in the literature. Risk factors in chronic opioid therapy patients are dynamic in that they can change with disease progression, tolerance, changes in pain quality, mental health, comorbidities, other drug therapies or drug interactions, and changes in the patient's lifestyle.

CONCLUSION

Opioid analgesic therapy must be tailored to carefully monitor all patients in order to minimize misuse and abuse, since the risk is constant and dynamic and therefore every patient is at some degree of risk for opioid misuse.

Results of a double-blind, placebo-controlled, fixed-dose assessment of once-daily OROS® hydromorphone ER in patients with moderate to severe pain associated with chronic osteoarthritis

OBJECTIVE

Opioids are recommended for patients with moderate to severe pain due to osteoarthritis (OA), who do not receive adequate analgesia from nonopioid treatment. The objective of this study was to evaluate the efficacy and safety of OROS hydromorphone extended-release (ER) compared with placebo in patients with moderate to severe pain associated with OA.

METHODS

This was a randomized, placebo-controlled, double-blind, fixed-dose study. Patients received placebo or fixed-dose OROS hydromorphone ER (8 or 16 mg). The primary efficacy measure was pain intensity score (11-point Numeric Rating Scale) at Maintenance Week 12, analyzed with baseline observation carried forward (BOCF) imputation for missing data.

RESULTS

This study did not meet the primary efficacy measure using the BOCF imputation. Study discontinuation was high (52%). When analyzed using last observation carried forward (LOCF) imputation, the prespecified alternate method, OROS hydromorphone ER 16 mg provided significantly better analgesia than placebo (P = 0.0009). Treatment was associated with significant improvements in patient global assessment (P = 0.01), the overall Western Ontario and McMaster Osteoarthritis Index (WOMAC) (P = 0.0003), and its subscales: pain (P = 0.0001), stiffness (P = 0.0023), and physical function (P = 0.0006). Gastrointestinal adverse events, such as constipation and nausea, were common among patients receiving OROS hydromorphone ER.

CONCLUSIONS

OROS hydromorphone ER failed to achieve statistical significance for the primary endpoint using the prespecified imputation method (BOCF), likely due to the high discontinuation rate associated with the fixed-dose design. When data were analyzed according to an alternate method of imputation (LOCF), OROS hydromorphone ER demonstrated statistically significant improvements in pain, stiffness, and physical function.

Cancer Pain Management and Bone Metastases: An Update for the Clinician

Breast cancer patients with bone metastases often suffer from cancer pain. In general, cancer pain treatment is far from being optimal for many patients. To date, morphine remains the gold standard as first-line therapy, but other pure μ agonists such as hydromorphone, fentanyl, or oxycodone can be considered. Transdermal opioids are an important option if the oral route is impossible. Due to its complex pharmacology, methadone should be restricted to patients with difficult pain syndromes. The availability of a fixed combination of oxycodone and naloxone is a promising development for the reduction of opioid induced constipation. Especially bone metastases often result in breakthrough pain episodes. Thus, the provision of an on-demand opioid (e.g., immediate-release morphine or rapid-onset fentanyl) in addition to the baseline (regular) opioid therapy (e.g., sustained-release morphine tablets) is mandatory. Recently, rapid onset fentanyls (buccal or nasal) have been strongly recommended for breakthrough cancer pain due to their fast onset and their shorter duration of action. If available, metamizole is an alternative non-steroid-anti-inflammatory-drug. The indication for bisphosphonates should always be checked early in the disease. In advanced cancer stages, glucocorticoids are an important treatment option. If bone metastases lead to neuropathic pain, coanalgetics (e.g., pregabalin) should be initiated. In localized bone pain, radiotherapy is the gold standard for pain reduction in addition to pharmacologic pain management. In diffuse bone pain radionuclids (such as samarium) can be beneficial. Invasive measures (e.g., neuroaxial blockage) are rarely necessary but are an important option if patients with cancer pain syndromes are refractory to pharmacologic management and radiotherapy as described above. Clinical guidelines agree that cancer pain management in incurable cancer is best provided as part of a multiprofessional palliative care approach and all other domains of suffering (psychosocial, spiritual, and existential) need to be carefully addressed («total pain»).

Minimally invasive surgery compared to open spinal fusion for the treatment of degenerative lumbar spine pathologies

This clinical study prospectively compares the results of open surgery to minimally invasive fusion for degenerative lumbar spine pathologies. Eighty-two patients were studied (41 minimally invasive surgery [MIS] spinal fusion, 41 open surgical equivalent) under a single surgeon (R. J. Mobbs). The two groups were compared using the Oswestry Disability Index, the Short Form-12 version 1, the Visual Analogue Scale score, the Patient Satisfaction Index, length of hospital stay, time to mobilise, postoperative medication and complications. The MIS cohort was found to have significantly less postoperative pain, and to have met the expectations of a significantly greater proportion of patients than conventional open surgery. The patients who underwent the MIS approach also had significantly shorter length of stay, time to mobilisation, lower opioid use and total complication rates. In our study MIS provided similar efficacy to the conventional open technique, and proved to be superior with regard to patient satisfaction, length of hospital stay, time to mobilise and complication rates.

Use of opioid analgesics in the treatment of cancer pain: evidence-based recommendations from the EAPC

Here we provide the updated version of the guidelines of the European Association for Palliative Care (EAPC) on the use of opioids for the treatment of cancer pain. The update was undertaken by the European Palliative Care Research Collaborative. Previous EAPC guidelines were reviewed and compared with other currently available guidelines, and consensus recommendations were created by formal international expert panel. The content of the guidelines was defined according to several topics, each of which was assigned to collaborators who developed systematic literature reviews with a common methodology. The recommendations were developed by a writing committee that combined the evidence derived from the systematic reviews with the panellists' evaluations in a co-authored process, and were endorsed by the EAPC Board of Directors. The guidelines are presented as a list of 16 evidence-based recommendations developed according to the Grading of Recommendations Assessment, Development and Evaluation system.

Perioperative management of the child on long-term opioids

The strategies used to manage children exposed to long-term opioids are extrapolated from adult literature. Opioid consumption during the perioperative period is more than three times that observed in patients not taking chronic opioids. A sparing use of opioids in the perioperative period results in both poor pain management and withdrawal phenomena. The child's pre-existing opioid requirement should be maintained, and acute pain associated with operative procedures should be managed with additional analgesia. This usually comprises short-acting opioids, regional or local anesthesia, and adjuvant therapies. Long-acting opioids, transdermal opioid patches, and implantable pumps can be used to maintain the regular opioid requirement. Intravenous infusion, nurse controlled analgesia, patient-controlled analgesia, or oral formulations are invaluable for supplemental requirements postoperatively. Effective management requires more than simply increasing opioid dose during this time. Collaboration of the child, family, and all teams involved is necessary. While chronic pain or palliative care teams and other staff experienced with the care of children suffering chronic pain may have helpful input, many pediatric hospitals do not have chronic pain teams, and many patients receiving long-term opioids are not palliative. Acute pain services are appropriate to deal with those on long-term opioids in the perioperative setting and do so successfully in many centers. Staff caring for such children in the perioperative period should be aware of the challenges these children face and be educated before surgery about strategies for postoperative management and discharge planning.

The effect of age on opioid switching to methadone: a systematic review

BACKGROUND

The aim of this review was to assess from the existing literature the effect of age on the outcome of opioid switching to methadone, and the possible influence on conversions ratios.

DISCUSSION

Older patients represent a challenge for physicians, as a further factor may play a role in dosing methadone and possibly on successful switching. Although existing data are not conclusive because this aspect did not receive particular attention in most studies, at the present time age has not been found to be independently associated with the dose ratio. Further prospective studies in a large sample of patients, subgrouped for classes of age, opioid doses, and reasons to switch, should be designed to provide more information.

[Cancer pain in palliative medicine]

During the course of cancer progression up to 90% of the patients suffer from pain of nociceptive, neuropathic or mixed nociceptive/neuropathic origin. Psychological, social or existential factors may additionally affect the intensity of pain (concept of "total pain"). The WHO "analgesic ladder" provides a large variety of effective drugs that can be used according to the specific pain type. Parenteral or peridural opioid therapy as well as neurodestructive methods can effectively support the analgesic treatment in selected cases.

Opioid rotation with extended-release opioids: where should we begin?

Opioid rotation is a common and necessary clinical practice in the management of chronic non-cancer pain to improve therapeutic efficacy with the lowest opioid dose. When dose escalations fail to achieve adequate analgesia or are associated with intolerable side effects, a trial of a new opioid should be considered. Much of the scientific rationale of opioid rotation is based on the wide interindividual variability in sensitivity to opioid analgesics and the novel patient response observed when introducing an opioid-tolerant patient to a new opioid. This article discusses patient indicators for opioid rotation, the conversion process between opioid medications, and additional practical considerations for increasing the effectiveness of opioid therapy during a trial of a new opioid. A Patient vignette that demonstrates a step-wise approach to opioid rotation is also presented.

Psychological variables potentially implicated in opioid-related mortality as observed in clinical practice

Opioid-related deaths in the United States have become a public health problem, with accidental and unintended overdoses being especially troubling. Screening for psychological risk factors is an important first step in safeguarding against nonadherence practices and identifying patients who may be vulnerable to the risks associated with opioid therapy. Validated screening instruments can aid in this attempt as a complementary tool to clinicians' assessments. A structured screening is imperative as part of an assessment, as clinician judgment is not the most reliable method of identifying nonadherence. As a complement to formal screening, we present for discussion and possible future study certain psychological variables observed during years of clinical practice that may be linked to medication nonadherence and accidental overdose. These variables include catastrophizing, fear, impulsivity, attention deficit disorders, existential distress, and certain personality disorders. In our experience, chronic pain patients with dual diagnoses may become "chemical copers" as a way of coping with their negative emotion. For these patients, times of stress could lead to accidental overdose. Behavioral, cognitive-behavioral (acceptance and commitment, dialectical behavior), existential (meaning-centered, dignity), and psychotropic therapies have been effective in treating these high-risk comorbidities, while managing expectations of pain relief appears key to preventing accidental overdose.

An analysis of the root causes for opioid-related overdose deaths in the United States

OBJECTIVE

A panel of experts in pain medicine and public policy convened to examine root causes and risk factors for opioid-related poisoning deaths and to propose recommendations to reduce death rates.

METHODS

Panelists reviewed results from a search of PubMed and state and federal government sources to assess frequency, demographics, and risk factors for opioid-related overdose deaths over the past decade. They also reviewed results from a Utah Department of Health study and a summary of malpractice lawsuits involving opioid-related deaths.

RESULTS

National data demonstrate a pattern of increasing opioid-related overdose deaths beginning in the early 2000s. A high proportion of methadone-related deaths was noted. Although methadone represented less than 5% of opioid prescriptions dispensed, one third of opioid-related deaths nationwide implicated methadone. Root causes identified by the panel were physician error due to knowledge deficits, patient non-adherence to the prescribed medication regimen, unanticipated medical and mental health comorbidities, including substance use disorders, and payer policies that mandate methadone as first-line therapy. Other likely contributors to all opioid-related deaths were the presence of additional central nervous system-depressant drugs (e.g., alcohol, benzodiazepines, and antidepressants) and sleep-disordered breathing.

CONCLUSIONS

Causes of opioid-related deaths are multifactorial, so solutions must address prescriber behaviors, patient contributory factors, nonmedical use patterns, and systemic failures. Clinical strategies to reduce opioid-related mortality should be empirically tested, should not reduce access to needed therapies, should address risk from methadone as well as other opioids, and should be incorporated into any risk evaluation and mitigation strategies enacted by regulators.

Experience with an extended-release opioid formulation designed to reduce abuse liability in a community-based pain management clinic

CONTEXT

With the growing public health concern over rising rates of opioid abuse, physicians have a responsibility to incorporate safeguards into their practice to minimize the potential for opioid misuse, abuse, and diversion. Patient-specific treatment regimens should include steps to monitor treatment success with regard to optimal pain management as well as inappropriate use of opioids and other substances. Opioid formulations designed to be less attractive for abuse are also being developed. While future studies are needed to determine the impact of such formulations in addressing the issue of opioid misuse in the community as a whole, the experience of practitioners who have utilized these formulations can highlight the practical steps to incorporate such formulations into the everyday patient-care setting.

PURPOSE

The purpose of this report is to describe experience in managing patients with chronic, moderate-to-severe pain using morphine sulfate and naltrexone hydrochloride extended release capsules (MS-sNT) (EMBEDA(®), King Pharmaceuticals(®) Inc, Bristol, TN, which was acquired by Pfizer Inc, New York, NY, in March 2011), a formulation designed with features to deter abuse/misuse, in a community-based pain management clinic.

CASE PRESENTATIONS

Case reports demonstrating a clinical management plan for assessment, initial interview procedures, explanation/discussion of proposed therapies, patients' treatment goals, conversion to MS-sNT, and titration and treatment outcomes are provided.

RESULTS

The management approach yielded successful outcomes including pain relief, improved quality of life, treatment satisfaction, and patient acceptance of a formulation designed to deter abuse/misuse.

DISCUSSION

The cases presented demonstrate that the communication accompanying complete pretreatment assessment, goal-setting and expectations, and attention to individual patient needs can enable optimization of pain-related outcomes, resulting in improved quality of life for patients and fostering patient acceptance of formulations designed to help address opioid abuse/misuse issues in the community at large.

Switching from oxycodone to methadone in advanced cancer patients

PURPOSE

The aim of this study was to prospectively evaluate the outcomes and the conversion ratio of switching from oxycodone to methadone in advanced cancer patients admitted to an acute palliative care unit.

PATIENTS AND METHODS

A prospective study was carried out on a cohort of consecutive sample of patients receiving oxycodone, who were switched for different reasons mainly because of an inconvenient balance between analgesia and adverse effects. An initial conversion ratio between oxycodone and methadone was 3.3:1. Intensity of pain and symptoms associated with opioid therapy were recorded, and a distress score (DS) was also calculated as a sum of symptom intensity. A successful switching was considered when the intensity of pain and/or DS or the principal symptom requiring switching decreased at least of 33% of the value recorded before switching.

RESULTS

Nineteen out of 542 patients admitted to the unit in 1 year underwent a switching from oxycodone to methadone. Almost all substitutions were successful. The prevalent indication for opioid switching was uncontrolled pain and adverse effects (12 patients). No significant changes between the initial conversion ratio and final conversion ratio between the two opioids were found.

CONCLUSION

Switching from oxycodone to methadone is a reliable method to improve the opioid response in advanced cancer patients. A ratio of 3.3 appears to be reliable, even at high doses. Further studies should be performed to confirm these results in other settings and with very high doses of oxycodone.

Conversion ratios for opioid switching in the treatment of cancer pain: a systematic review

In this paper we describe the results of a systematic search of the literature on conversion ratios during opioid switching. This is part of a project of the European Palliative Care Research Collaboration to update the European Association for Palliative Care recommendations for the use of opioid analgesics in the treatment of cancer pain. Studies were eligible for inclusion if they involved adult patients with chronic cancer pain, contained data on opioid conversion ratios, were prospective and were written in English. Thirty-one studies were identified and included. The majority of the studies had methodological flaws and were not designed to explore or demonstrate equianalgesic dose data. However, the data allow some recommendations to be made that could be helpful to clinicians for whom there are few reliable experimental data on which to base dosing guidelines. Switching to transdermal fentanyl (TDfe) or buprenorphine (TDbu) is an option for patients with stable, controlled pain. Reliable and consistent studies show a ratio of 100 : 1 between oral morphine (ORmo) and TDfe. A ratio of 75 : 1 between ORmo and TDbu may be appropriate, but the supporting evidence here is much less robust. Data are relatively consistent to support a conversion ratio between ORmo and oral hydromorphone (ORhy) of 5 : 1. Despite some limitations, there is evidence to support the use of an approximate conversion ratio of ORmo:oral oxycodone (ORox) of 1.5 : 1. The conversion between ORox and ORhy is estimated to be 1 : 4. When switching from different opioids to methadone the conversion ratio is highly variable, ranging from 5 : 1 to 10 : 1 and much higher in some studies. The derived ratios are influenced by several factors, including the reasons for switching and previous opioid doses. An individual treatment decision and strict monitoring is recommended for patients considered at risk.

Treatment of cancer pain

In patients with active cancer, the management of chronic pain is an essential element in a comprehensive strategy for palliative care. This strategy emphasises multidimensional assessment and the coordinated use of treatments that together mitigate suffering and provide support to the patient and family. This review describes this framework, an approach to pain assessment, and widely accepted techniques to optimise the safety and effectiveness of opioid drugs and other treatments. The advances of recent decades suggest a future that includes increased evidence-based targeting of specific analgesic interventions within an individualised plan of care that is appropriate throughout the course of illness.

Comparative mortality among Department of Veterans Affairs patients prescribed methadone or long-acting morphine for chronic pain

Data on comparative safety of opioid analgesics are limited, but some reports suggest disproportionate mortality risk associated with methadone. Our objective was to compare mortality rates among patients who received prescribed methadone or long-acting morphine for pain. This is a retrospective observational cohort drawn from Department of Veterans Affairs (VA) health care databases, January 1, 2000, to December 31, 2007. We included 28,554 patients who received methadone and 79,938 who received long-acting morphine from VA pharmacies. Compared with those who received long-acting morphine, patients who received methadone were younger, less likely to have some medical comorbidities, and more likely to have psychiatric and substance use disorders. Patients were stratified into quintiles according to propensity score; the probability of receiving methadone was conditional on demographic, clinical, and VA service area variables. Overall propensity-adjusted mortality was lower for methadone than for morphine. Hazard ratios varied across propensity score quintiles; the magnitude of the between-drug difference in mortality decreased as the propensity to receive methadone increased. Mortality was significantly lower for methadone in all but the last quintile, in which there was no between-drug difference in mortality (hazard ratio=0.92, 95% confidence interval=0.74, 1.16). Multiple sensitivity analyses found either no difference in mortality between methadone and long-acting morphine or lower mortality rates among patients who received methadone. In summary, we found no evidence of excess all-cause mortality among VA patients who received methadone compared with those who received long-acting morphine. Randomized trials and prospective observational research are needed to better understand the relative safety of long-acting opioids.

Use of opioids in long-term management of temporomandibular joint dysfunction

The long-term treatment of patients with chronic temporomandibular joint dysfunction has been challenging. The long-term use of opioids in these patients can be neither supported nor refuted based on current evidence. However, evidence is available to support the long-term use of opioids in other chronic noncancer pain states with reduced pain, improved function, and improved quality of life. One group of patients with chronic temporomandibular joint pain, for whom both noninvasive and invasive treatment has failed, might benefit from long-term opioid medication. The choices include morphine, fentanyl, oxycodone, tramadol, hydrocodone, and methadone. Adjunct medication, including antidepressant and anticonvulsant drugs, can also be used. The safety of these medications has been well established, but the potential for adverse drug-related behavior does exist, requiring appropriate patient selection, adequate monitoring, and intervention when needed.

Pharmacological management of persistent pain in older persons: focus on opioids and nonopioids

Managing persistent pain is challenging, particularly in older adults who often have comorbidities and physiological changes that affect dosing and adverse effect profiles. The latest guideline issued by the American Geriatrics Society in 2009 is an important clinical resource on prescribing analgesics for older adults. This guideline helps form an evidence-based approach to treating persistent pain, along with other current endorsements, such as the relevant disease-specific recommendations by the American College of Rheumatology, the European League Against Rheumatism, and Osteoarthritis Research Society International, as well as opioid-specific guidelines issued by the American Pain Society, the American Academy of Pain Medicine, the Federation of State Medical Boards of the United States, and the American Society of Interventional Pain Physicians. Safety is of utmost concern, especially for older adults; these guidelines include key approaches for safe opioid prescribing. Combining analgesics that have multiple mechanisms of action with nonpharmaceutical approaches can be beneficial in providing pain relief. Nontraditional analgesics are also considered on a case-by-case basis, and a few of these options are weakly recommended. Therapies should be initiated at the lowest possible dose and slowly titrated to effect, while tailoring them to the therapeutic and side-effect responses of the individual.

Practical approaches to pharmacologic management of pain in older adults with cancer

PURPOSE/OBJECTIVES

To identify appropriate strategies for pharmacotherapeutic agents in the management of pain in older adults with cancer.

DATA SOURCES

PubMed literature searches, personal reference collection, and clinical experience.

DATA SYNTHESIS

To make good decisions about pain management when developing treatment plans for older adults, healthcare providers should focus on the pharmacokinetic and pharmacodynamic properties of drugs in the context of the physiologic changes that occur with aging.

CONCLUSIONS

Unrelieved pain can have a detrimental effect on older adults; conversely, overmedicating can lead to an increased risk of adverse events. With advancing age, physiologic changes alter the pharmacokinetic and pharmacodynamic properties of drugs by reducing their absorption, changing their distribution, and modifying their metabolism and elimination. Also, common comorbidities increase the risk of pharmacologic toxicity and narrow the therapeutic window. In addition, polypharmacy-an issue more common in older adults-increases the complexity of prescribing and risk of adverse events. Consequently, older adults require individualization of their pharmacotherapies. Healthcare providers should consider carefully the risks and benefits of nonsteroidal anti-inflammatory drugs, opioids, and adjuvants before initiating an analgesic trial. The 2009 guidelines published by the American Geriatrics Society described several key principles for prescribing analgesics to older adults and offered specific recommendations and caveats for each drug class.

IMPLICATIONS FOR NURSING

Current guidelines support appropriate management of cancer pain in older adults with specific recommendations for each class of analgesics as well as general prescribing principles.

The use of opioids at the end of life: the knowledge level of Dutch physicians as a potential barrier to effective pain management

BACKGROUND

Pain is still one of the most frequently occurring symptoms at the end of life, although it can be treated satisfactorily in most cases if the physician has adequate knowledge. In the Netherlands, almost 60% of the patients with non-acute illnesses die at home where end of life care is coordinated by the general practitioner (GP); about 30% die in hospitals (cared for by clinical specialists), and about 10% in nursing homes (cared for by elderly care physicians).The research question of this study is: what is the level of knowledge of Dutch physicians concerning pain management and the use of opioids at the end of life?

METHODS

A written questionnaire was sent to a random sample of physicians of specialties most often involved in end of life care in the Netherlands. The questionnaire was completed by 406 physicians, response rate 41%.

RESULTS

Almost all physicians were aware of the most basal knowledge about opioids, e.g. that it is important for treatment purposes to distinguish nociceptive from neuropathic pain (97%). Approximately half of the physicians (46%) did not know that decreased renal function raises plasma concentration of morphine(-metabolites) and 34% of the clinical specialists erroneously thought opioids are the favoured drug for palliative sedation.Although 91% knew that opioids titrated against pain do not shorten life, 10% sometimes or often gave higher dosages than needed with the explicit aim to hasten death. About half felt sometimes or often pressured by relatives to hasten death by increasing opioiddosage.The large majority (83%) of physicians was interested in additional education about subjects related to the end of life, the most popular subject was opioid rotation (46%).

CONCLUSIONS

Although the basic knowledge of physicians was adequate, there seemed to be a lack of knowledge in several areas, which can be a barrier for good pain management at the end of life. From this study four areas emerge, in which it seems likely that an improvement can improve the quality of pain management at the end of life for many patients in the Netherlands: 1)palliative sedation; 2)expected effect of opioids on survival; and 3) opioid rotation.

Sufentanil for chronic pain management

Sufentanil is a highly potent synthetic opioid that is approximately 1000-fold more potent than morphine and up to tenfold more potent than fentanyl. It is most commonly used by anesthesiologists to provide intraoperative analgesia. Although sufentanil is not yet approved for chronic pain management, it is being explored for chronic pain therapy. Owing to its physical properties, high potency, high lipid solubility, high therapeutic index and short duration of action, sufentanil has the potential to provide effective analgesia via multiple routes of administration. The superior pharmacokinetics of sufentanil make it ideal for treatment of breakthrough pain via the sublingual/buccal and nasal routes. Similarly, the transdermal route of sufentanil administration should provide analgesia for a prolonged period. The adverse effects of sufentanil are similar to those of other opioids that are commonly used for chronic pain management (e.g., fentanyl and morphine). Future research is necessary to define the role of sufentanil in the treatment of chronic pain.

Effects of opioid rotation in chronic pain patients: ORTIBARN study

BACKGROUND

Opioid rotation is currently the subject of considerable debate for two reasons: firstly as a strategy for pain treatment, and secondly because of the difficulty in determining equianalgesic doses. Switching from one slow-release (SR) opioid analgesic to another raises a number of critical issues, and there are no widespread studies that support a standard protocol. Initiation of opioid therapy must consider gradual dose titration of the drug until the minimum effective and maximum tolerated dosage for each patient is found.

OBJECTIVE

This study aimed to evaluate the effects of SR opioid rotation after a stabilization period with normal-release (NR) morphine ('start therapy') in patients with cancer or non-cancer pain not controlled with their current SR opioid.

METHODS

This is a multicentre, open-label, prospective study. A total of 326 consecutive patients were enrolled who were affected by chronic cancer or non-cancer pain that was not controlled by an SR opioid administered as either monotherapy or in combination with other analgesic drugs. Following start therapy with oral NR morphine at a dosage of 5 mg or 10 mg every 4 hours, rotation to an SR opioid of a different type from that previously administered was carried out.

RESULTS

After about 3 days of start therapy with NR morphine, rotation to an SR opioid allowed a significant decrease of both baseline pain and daily episodes of breakthrough pain. No significant difference was detected between dosages and type of opioid administered, both prior to and after the start therapy period with NR morphine.

CONCLUSIONS

Rotation to another opioid preceded by a brief period of opioid receptor resetting by start therapy with NR morphine allows a good level of pain control and avoids rotation to inappropriate opioid dosages or combinations analgesics.

Oxycodone combinations for pain relief

No single analgesic drug provides the perfect therapeutic/adverse effect profile for every pain condition. In addition to convenience and possibly improved compliance, a combination of analgesic drugs offers the potential, requiring verification, of providing greater pain relief and/or reduced adverse effects than the constituent drugs when used individually. We review here analgesic combinations containing oxycodone. We found surprisingly little preclinical information about the analgesic or adverse effect profiles of the combinations (with acetaminophen, paracetamol, nonsteroidal anti-inflammatory drugs, morphine, gabapentin or pregabalin). Clinical experience and studies suggest that the combinations are safe and effective and may offer certain advantages. As with all combinations, the profile of adverse effects must also be determined in order to provide the clinician with the overall benefit/risk assessment.

Establishing "best practices" for opioid rotation: conclusions of an expert panel

Opioid rotation is a strategy applied during opioid therapy for pain that refers to a switch from one opioid to another in an effort to improve clinical outcomes (benefits or harms). It begins with the selection of a new drug at a starting dose that minimizes potential risks while ideally maintaining analgesic efficacy. The selection of a starting dose must be informed by an estimate of the relative potency between the existing opioid and the new one. Clinically relevant estimates of relative analgesic potency have been codified in the "equianalgesic dose table," which has been used with little modification for more than 40 years. New information about relative potency and the growing implementation of long-term opioid therapy for chronic pain provided a strong rationale for the convening of an expert panel to discuss the scientific foundation to opioid rotation and the elements that now should inform a clinical guideline for this practice. The panel affirmed both the value and the limitations of the current equianalgesic dose table and proposed a guideline intended to promote safety during opioid rotation.