Multicenter, open-label, prospective evaluation of the conversion from previous opioid analgesics to extended-release hydromorphone hydrochloride administered every 24 hours to patients with persistent moderate to severe pain

Opioid Switch Dosing in Chronic Cancer Pain: A Prospective Longitudinal Study

Background: Opioid switching is common, however, conversion tables have limitations. Guidelines suggest postswitch dose reduction, yet, observations show opioid doses may increase postswitch. Objectives: To document the opioid conversion factor postswitch in cancer, and whether pain and adverse effect outcomes differ between switched opioid groups. Design/Setting: This multicenter prospective longitudinal study included people with advanced cancer in Australia. Clinical data (demographics, opioids) and validated instruments (pain, adverse effects) were collected twice, seven days apart. Results: Opioid switch resulted in dose increase (median oral morphine equivalent daily dose 90 mg [interquartile range {IQR} 45-184] to 150 mg [IQR 79-270]), reduced average pain (5.1 [standard deviation {SD} 1.7] to 3.8 [SD 1.6]), and reduced adverse effects. Hydromorphone dose increased 2.5 times (IQR 1.0-3.6) above the original conversion factor used. Conclusions: Opioid switching resulted in overall dose increase, particularly when switching to hydromorphone. Higher preswitch dosing may require higher dose conversion ratios. Dose reduction postswitch risks undertreatment and may not be always appropriate.

The 50% effective dose of hydromorphone and morphine for epidural analgesia in the hemorrhoidectomy: a double-blind, sequential dose-finding study

BACKGROUND

Although previous studies have showed that epidural morphine can be used as a complement to local anesthetics for analgesia after postcesarean delivery under spinal anesthesia, there is little known about the analgesic dosage of epidural morphine and hydromorphone for hemorrhoidectomy. Therefore, we conducted this study to examine the potency ratio of hydromorphone to epidural morphine as well as effective analgesic dose for 50% patients (ED50) undergoing elective hemorrhoidectomy.

METHODS

80 patients under elective hemorrhoidectomy with combined spinal and epidural anesthesia(CSEA) in department of anesthesia, Dongguan Tungwah hospital. To assess the ED50, patients were treated with epidural morphine or epidural hydromorphone randomly using a biased coin method-determined dose with a sequential allocation procedure. Following surgery, standardized multimodal analgesia was administered to all patients. A pain response score of ≤ 3 (on a scale of 0-10) was determined to be the effective dose after 24 h following CSEA. The ED50 in both groups were determined using the probit regression and isotonic regression method. We also measured pain intensity by patient interview using a 10 point verbal numeric rating scale prospectively at 6, 12 and 24 h after CSEA, and adverse effects were also noted.

RESULTS

The ED50 was 0.350 mg (95% CI, 0.259-0.376 mg) in hydromorphone group and 1.129 mg (95% CI, 0.903-1.187 mg) in morphine group, respectively, estimated by isotonic regression method. Regression analysis with the probit, the ED50 of epidural hydromorphone was 0.366 mg (95% CI, 0.276-0.388 mg) and epidural morphine was 1.138 mg (95% CI, 0.910-1.201 mg). Exploratory findings showed that there was no difference between the most frequent dosages of epidural hydromorphone or epidural morphine in the occurrence of nausea, vomiting and pruritus. When administered with epidural opioids at ED50 doses or higher, 97.5% (39/40) of epidural morphine patients and 97.5% (39/40) epidural hydromorphone of patients were satisfied with their analgesia.

CONCLUSION

Effective hemorrhoidectomy analgesia requires a 3:1 ratio of epidural morphine to epidural hydromorphone. Both drugs provide excellent patient satisfaction.

A double-blind, randomized comparative study to investigate the morphine to hydromorphone conversion ratio in Japanese cancer patients

Objective

To confirm the morphine to hydromorphone conversion ratio for hydromorphone (DS-7113b) immediate-release tablets in cancer patients who achieved pain control with oral morphine.

Methods

This was a multicenter, active-controlled, randomized, double-blind, parallel-group, comparative study (July 2013 to December 2014) at 39 Japanese sites. Seventy-one patients (aged >20 years) who had achieved pain control with morphine 60 mg/day and 90 mg/day were randomly allocated 1:1 to hydromorphone immediate-release tablets at a dose converted at a hydromorphone:morphine ratio of 1:5 or 1:8, respectively, and treated for up to 5 days. The efficacy was evaluated as the pain control ratio.

Results

The pain control ratio in the full analysis set was 83.3% (25/30) in the conversion ratio 1:5 group and 95.0% (38/40) in the conversion ratio 1:8 group, and both groups demonstrated highly successful pain control. The incidence of adverse events was 46.7% (14/30) in the conversion ratio 1:5 group and 58.5% (24/41) in the 1:8 group; the difference was not clinically relevant. Frequently observed adverse events (incidence ≥5%) were nausea, vomiting, diarrhea, somnolence and dyspnea.

Conclusions

A high pain control ratio was maintained by a switch at either conversion ratio, and no notable difference was observed in the incidence of adverse events. A switch from morphine to hydromorphone is effective at a dose converted at ratios of 1:5 and 1:8.

Interventions for the reduction of prescribed opioid use in chronic non-cancer pain

BACKGROUND

This is the first update of the original Cochrane Review published in 2013. The conclusions of this review have not changed from the 2013 publication. People with chronic non-cancer pain who are prescribed and are taking opioids can have a history of long-term, high-dose opioid use without effective pain relief. In those without good pain relief, reduction of prescribed opioid dose may be the desired and shared goal of both patient and clinician. Simple, unsupervised reduction of opioid use is clinically challenging, and very difficult to achieve and maintain.

OBJECTIVES

To investigate the effectiveness of different methods designed to achieve reduction or cessation of prescribed opioid use for the management of chronic non-cancer pain in adults compared to controls.

SEARCH METHODS

For this update we searched CENTRAL, MEDLINE, and Embase in January 2017, as well as bibliographies and citation searches of included studies. We also searched one trial registry for ongoing trials.

SELECTION CRITERIA

Included studies had to be randomised controlled trials comparing opioid users receiving an intervention with a control group receiving treatment as usual, active control, or placebo. The aim of the study had to include a treatment goal of dose reduction or cessation of opioid medication.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed risk of bias. We sought data relating to prescribed opioid use, adverse events of opioid reduction, pain, and psychological and physical function. We planned to assess the certainty of the evidence using the GRADE approach, however, due to the heterogeneity of studies, we were unable to combine outcomes in a meta-analysis and therefore we did not assess the evidence with GRADE.

MAIN RESULTS

Three studies are new to this update, resulting in five included studies in total (278 participants). Participants were primarily women (mean age 49.63 years, SD = 11.74) with different chronic pain conditions. We judged the studies too heterogeneous to pool data in a meta-analysis, so we have summarised the results from each study qualitatively. The studies included acupuncture, mindfulness, and cognitive behavioral therapy interventions aimed at reducing opioid consumption, misuse of opioids, or maintenance of chronic pain management treatments. We found mixed results from the studies. Three of the five studies reported opioid consumption at post-treatment and follow-up. Two studies that delivered 'Mindfulness-Oriented Recovery Enhancement' or 'Therapeutic Interactive Voice Response' found a significant difference between groups at post-treatment and follow-up in opioid consumption. The remaining study found reduction in opioid consumption in both treatment and control groups, and between-group differences were not significant. Three studies reported adverse events related to the study and two studies did not have study-related adverse events. We also found mixed findings for pain intensity and physical functioning. The interventions did not show between-group differences for psychological functioning across all studies. Overall, the risk of bias was mixed across studies. All studies included sample sizes of fewer than 100 and so we judged all studies as high risk of bias for that category.

AUTHORS' CONCLUSIONS

There is no evidence for the efficacy or safety of methods for reducing prescribed opioid use in chronic pain. There is a small number of randomised controlled trials investigating opioid reduction, which means our conclusions are limited regarding the benefit of psychological, pharmacological, or other types of interventions for people with chronic pain trying to reduce their opioid consumption. The findings to date are mixed: there were reductions in opioid consumption after intervention, and often in control groups too.

The Conversion Ratio From Intravenous Hydromorphone to Oral Opioids in Cancer Patients

CONTEXT

The lack of knowledge of the accurate conversion ratio (CR) between intravenous (IV) and oral hydromorphone and opioid rotation ratio (ORR) between IV hydromorphone and oral morphine equivalent daily dose (MEDD) may lead to poorly controlled pain or overdosing in cancer inpatients.

OBJECTIVES

We aimed to determine the CR and ORR from IV hydromorphone to oral hydromorphone and MEDD (obtained from oral morphine and oxycodone).

METHODS

A total of 4745 consecutive inpatient palliative care consults during 2010-14 were reviewed for conversions from IV hydromorphone to oral hydromorphone, morphine or oxycodone. Patient characteristics, symptoms, and opioid doses were determined in patients successfully discharged on oral opioids without readmission within one week. Linear regression analysis was used to estimate the CR or ORR between the 24 hour IV hydromorphone mg dose before conversion and the oral opioid mg dose used before discharge.

RESULTS

Among 394 patients on IV hydromorphone, 147 underwent conversion to oral hydromorphone and 247 underwent rotation to oral morphine (163) or oxycodone (84). The median (interquartile range) CR from IV to PO hydromorphone was 2.5 (2.14-2.75) with correlation of 0.95 (P < 0.0001). The median ORR (interquartile range) from IV hydromorphone to MEDD was 11.46 (9.84-13.00) with correlation of 0.93(P < 0.0001). The median ORR was 11.54 in patients receiving <30 mg of IV hydromorphone/day and 9.86 in patients receiving ≥30 mg (P = 0.0004).

CONCLUSION

Our study found that 1 mg of IV hydromorphone is equivalent to 2.5 mg of oral hydromorphone and 11.46 mg of MEDD. Hydromorphone at doses ≥30 mg/day may require a lower ORR to other opioids.

Opioid Conversions in Acute Care

Objective:

To discuss the historical basis and limitations of opioid conversion tables, review the relevant literature, and establish an evidence-based equianalgesic dose ratio (EDR) table for performing conversions in the acute care setting.

Data Sources:

Articles were identified through searches of MEDLINE (1966–January 2007) using the key words opioid, tolerance, conversion, dose, equianalgesic, equipotent, acute care, morphine, hydromorphone, fentanyl, methadone, and oxycodone. Additional references were located through a review of the bibliographies of articles cited and references cited in conversion tables.

Study Selection and Data Extraction:

All data sources identified were evaluated, and all information deemed relevant was included, with the exception of case series and case reports when higher level evidence was available.

Data Synthesis:

Opioid conversion tables are published in major textbooks, medical references, national guidelines, and review articles. Some conversion tables do not accurately reflect the dose ratios for which evidence is available. There is marginal evidence-based clinical data to support the dose ratios cited in these tables, particularly in the acute care setting where the clinical status of patients often changes rapidly. The barriers when performing route and opioid-to-opioid conversions in the acute care setting are formidable, but EDRs are provided, based on the best available evidence.

Conclusions:

In the acute care setting, calculation of dose ratios for opioids, based solely on opioid conversion tables, is an oversimplification of pain management, with a potential for adverse consequences. The calculation of EDRs is one step in an interdisciplinary process that must take into account patient- and institution-specific factors.

Hydromorphone: evolving to meet the challenges of today's health care environment

BACKGROUND

Hydromorphone, a potent analogue of morphine, has long had an important role in pain management and is included in several international guidelines for managing pain. Advances in hydromorphone formulations and the ways in which hydromorphone is being used clinically today warrant a review of the drug's pharmacotherapeutic utility.

OBJECTIVE

The history and recent advances in hydromorphone pharmacotherapy are reviewed. Areas covered include the pharmacologic and metabolic profile of hydromorphone, the role of hydromorphone in pain management, formulations and routes of administration, and issues related to relative opioid potencies, equianalgesic ratios, and opioid rotation. Because hydromorphone, like all opioids, carries a risk of misuse, abuse, and illicit diversion, the related issues of tamper-resistant formulations and "dose-dumping" of extended-release formulations are discussed.

CONCLUSIONS

Due to the epidemic of prescription opioid overdoses associated with prescription opioid abuse in the United States, development of tamper-resistant opioid formulations that avoid dose-dumping issues has become a significant goal of pharmaceutical manufacturers. The current formulation of hydromorphone extended-release potentially provides the benefits of long-acting hydromorphone (ie, continuous pain control, increased quality of life, freedom to perform daily activities) to appropriate patients, while reducing the risks of abuse and without compromising safety.

Interventions for the reduction of prescribed opioid use in chronic non-cancer pain

BACKGROUND

Patients with chronic non-cancer pain who are prescribed and are taking opioids can have a history of long term high dose opioid use without effective pain relief. In those without good pain relief, reduction of prescribed opioid dose may be the desired and shared goal of both patient and clinician. Simple unsupervised reduction of opioid use is clinically challenging, and very difficult to achieve and maintain.

OBJECTIVES

To investigate the effectiveness of different methods designed to achieve reduction or cessation of prescribed opioid use for the management of chronic non-cancer pain.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and EMBASE from inception to 8th April 2013, as well as bibliographies.

SELECTION CRITERIA

Included studies had to be randomised controlled trials comparing opioid users receiving an intervention with a control group receiving treatment as usual, active control, or placebo. The aim of the study had to include a treatment goal of dose reduction or cessation of opioid medication.

DATA COLLECTION AND ANALYSIS

We sought data relating to prescribed opioid use, adverse events of opioid reduction, pain, and psychological and physical function.

MAIN RESULTS

Two studies provided information on 86 participants. One compared electroacupuncture with sham acupuncture for 20 minutes twice a week for six weeks; there was no difference between treatments. The other followed 11 weeks of cognitive behavioural therapy with either therapeutic interactive voice response through a computer for four months or usual treatment; the active group had a significant reduction in opioid use, while the usual care group had a significant increase.

AUTHORS' CONCLUSIONS

Both included studies were at significant risk of bias because of their small size, together with other important issues, including blinding. Because of this risk and the paucity of relevant studies, no conclusions can be drawn regarding the effectiveness of interventions for opioid withdrawal in chronic non-cancer pain.

Opioids compared to placebo or other treatments for chronic low-back pain

BACKGROUND

The use of opioids in the long-term management of chronic low-back pain (CLBP) has increased dramatically. Despite this trend, the benefits and risks of these medications remain unclear. This review is an update of a Cochrane review first published in 2007.

OBJECTIVES

To determine the efficacy of opioids in adults with CLBP.

SEARCH METHODS

We electronically searched the Cochrane Back Review Group's Specialized Register, CENTRAL, CINAHL and PsycINFO, MEDLINE, and EMBASE from January 2006 to October 2012. We checked the reference lists of these trials and other relevant systematic reviews for potential trials for inclusion.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that assessed the use of opioids (as monotherapy or in combination with other therapies) in adults with CLBP that were at least four weeks in duration. We included trials that compared non-injectable opioids to placebo or other treatments. We excluded trials that compared different opioids only.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the risk of bias and extracted data onto a pre-designed form. We pooled results using Review Manager (RevMan) 5.2. We reported on pain and function outcomes using standardized mean difference (SMD) or risk ratios with 95% confidence intervals (95% CI). We used absolute risk difference (RD) with 95% CI to report adverse effects.

MAIN RESULTS

We included 15 trials (5540 participants). Tramadol was examined in five trials (1378 participants); it was found to be better than placebo for pain (SMD -0.55, 95% CI -0.66 to -0.44; low quality evidence) and function (SMD -0.18, 95% CI -0.29 to -0.07; moderate quality evidence). Transdermal buprenorphine (two trials, 653 participants) may make little difference for pain (SMD -2.47, 95%CI -2.69 to -2.25; very low quality evidence), but no difference compared to placebo for function (SMD -0.14, 95%CI -0.53 to 0.25; very low quality evidence). Strong opioids (morphine, hydromorphone, oxycodone, oxymorphone, and tapentadol), examined in six trials (1887 participants), were better than placebo for pain (SMD -0.43, 95%CI -0.52 to -0.33; moderate quality evidence) and function (SMD -0.26, 95% CI -0.37 to -0.15; moderate quality evidence). One trial (1583 participants) demonstrated that tramadol may make little difference compared to celecoxib (RR 0.82, 95% CI 0.76 to 0.90; very low quality evidence) for pain relief. Two trials (272 participants) found no difference between opioids and antidepressants for either pain (SMD 0.21, 95% CI -0.03 to 0.45; very low quality evidence), or function (SMD -0.11, 95% -0.63 to 0.42; very low quality evidence). The included trials in this review had high drop-out rates, were of short duration, and had limited interpretability of functional improvement. They did not report any serious adverse effects, risks (addiction or overdose), or complications (sleep apnea, opioid-induced hyperalgesia, hypogonadism). In general, the effect sizes were medium for pain and small for function.

AUTHORS' CONCLUSIONS

There is some evidence (very low to moderate quality) for short-term efficacy (for both pain and function) of opioids to treat CLBP compared to placebo. The very few trials that compared opioids to non-steroidal anti-inflammatory drugs (NSAIDs) or antidepressants did not show any differences regarding pain and function. The initiation of a trial of opioids for long-term management should be done with extreme caution, especially after a comprehensive assessment of potential risks. There are no placebo-RCTs supporting the effectiveness and safety of long-term opioid therapy for treatment of CLBP.

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.

Fixed combination of oxycodone with naloxone: a new way to prevent and treat opioid-induced constipation

Morphine and other opioids increase tone and reduce propulsive motility in several segments of the gut, enhance absorption of fluids, and inhibit secretion. This opioid-induced bowel dysfunction may present as infrequent stools, hard stools, difficult defecation, bloating, and sense of incomplete emptying of the bowels, but also dry mouth, gastroesophageal reflux, epigastric fullness, and abdominal cramping. It afflicts about one-third of patients on opioid treatment. Lifestyle measures, such as regular toilet visits, physical activity, and fiber-rich diet, are very unlikely to be successful. Laxatives, such as bisacodyl, sodium picosulfate, sennosides, macrogols, and prucalopride, may relieve opioid-induced constipation (OIC) in a proportion of patients only. A new approach to counteract OIC is the coadministration of an opioid antagonist devoid of the potential to penetrate the brain. In the EU, an oxycodonenaloxone combination has been approved for this purpose. Both components are included in an oral extended-release preparation. Following its release, naloxone acts locally on the gut and antagonizes the inhibitory effect of the opioid. After being absorbed in parallel with oxycodone, naloxone is rapidly and completely inactivated by a high first-pass effect in the liver. In a 2:1 dose ratio it may improve OIC without interfering with the analgesic effect.

Use of hydromorphone, with particular reference to the OROS formulation, in the elderly

The prevalence of pain increases with age. However, pain is often inadequately managed in elderly people, which undermines quality of life. Pain has been associated with depression, sleep disturbances, impaired ambulation, and increased healthcare use and costs. Effective treatment of pain improves the overall quality of life. However, pain management is complicated by the presence of multiple co-morbidities in elderly people, which increases the likelihood of polypharmacy, and therefore increases the chance of potential drug-drug interactions. Polypharmacy is also associated with poor adherence to therapy. Age-related pharmacokinetic and pharmacodynamic changes reduce the therapeutic index of drugs. Therefore, elderly people are more likely to suffer from adverse events and increased sensitivity to the analgesic properties of opioids. OROS hydromorphone (Jurnista) is a once-daily, extended-release formulation that uses the OROS push-pull technology to provide controlled release of the semi-synthetic opioid hydromorphone. Compared with conventional immediate-release hydromorphone, OROS hydromorphone provides more consistent delivery of hydromorphone with lower peak concentrations and less variability in plasma concentrations over time. The bioavailability of hydromorphone from OROS hydromorphone is minimally affected by food or alcohol (ethanol). Hydromorphone is mainly metabolized in the liver and is excreted in the urine. Unlike morphine, hydromorphone does not have an active 6-glucuronide metabolite. This metabolite of morphine can accumulate in the presence of renal failure; therefore, the lack of an active 6-glucuronide metabolite makes hydromorphone a useful alternative to morphine in elderly patients with renal failure. However, hydromorphone is similar to morphine in that it is metabolized to hydromorphone-3-glucuronide, which may be neuroexcitatory. Because of its low plasma protein binding and low probability of interfering with the metabolism of other drugs, hydromorphone may be especially suitable for patients taking multiple medications. OROS hydromorphone is an effective analgesic that is well tolerated and provides more stable plasma concentrations than immediate-release forms of hydromorphone. Its once-daily administration offers an advantage over immediate-release forms and longer-acting formulations that require twice-daily administration. This means OROS hydromorphone will be more convenient for elderly patients and may improve adherence, resulting in improved pain relief and quality of life.

An open-label, 1-year extension study of the long-term safety and efficacy of once-daily OROS(R) hydromorphone in patients with chronic cancer pain

Background

Opioid analgesics have proven efficacy in the short-term management of chronic cancer pain, but data on their long-term use is more limited. OROS^® hydromorphone is a controlled-release formulation of oral hydromorphone that may be particularly well suited to long-term management of chronic cancer pain because it provides stable plasma concentrations and consistent analgesia with convenient once-daily dosing. The objective of this study (DO-118X) was to characterise the pain control achieved with long-term repeated dosing of OROS^® hydromorphone in patients with chronic cancer pain.

Methods

In this multicentre, phase III, open-label, single treatment, 1-year extension study, OROS^® hydromorphone was administered to 68 patients with moderate-to-severe chronic cancer pain, who had successfully completed a short-term equivalence study, and whose pain was controlled with a stable dose of medication (≥ 8 mg OROS^® hydromorphone or equivalent controlled-release morphine). Patients were started on the dose of OROS^® hydromorphone equivalent to the opioid dose on which they achieved dose-stable pain control in the equivalence study; dose adjustments were made as necessary and breakthrough pain medication was permitted. Efficacy was assessed with the Brief Pain Inventory (BPI) and patient and investigator global evaluations of treatment effectiveness. No formal statistical analysis was done.

Results

The mean (standard deviation) duration of exposure to study medication was 139 (129.9) days and the mean (standard deviation) average daily consumption of OROS^® hydromorphone was 43.7 (28.14) mg/day. All scores were maintained at a mild to moderate severity throughout the study; however, BPI scores for pain at its worst, pain at its least, pain on average, pain right now, and pain relief were slightly worsened at end point compared with baseline. Mean BPI pain interference with daily activities and patient and investigator global evaluation scores also remained generally stable. Treatment effectiveness was rated as fair to good throughout the study. The most frequently reported adverse events were nausea (n = 24, 35.3%), constipation (n = 22, 32.4%), and vomiting (n = 15, 22.1%).

Conclusion

The results of this extension study suggest that long-term repeated dosing with once-daily OROS^® hydromorphone can be beneficial in the continuing management of persistent, moderate-to-severe cancer pain.

A new extended release formulation (OROS) of hydromorphone in the management of pain

Opioid analgesics are essential in the treatment of moderate to severe cancer-related pain. Opioids are also recognized as important in the management of other severe, persistent refractory painful conditions, such as sickle cell disease and arthritis. In the clinical practice of pain management, stable opioid dosing generally depends on achieving maximal analgesia with tolerable side effects typical of opioid analgesics. There is a wide interindividual variability of responsiveness to exogenous opioids both in terms of analgesic efficacy and side effects. Optimizing pain management for the individual patient may require sequential trials of opioid medications until the regimen with the most favorable therapeutic ratio of efficacy to side effects is determined.

Conversion from standard opioid therapy to once-daily oral extended-release hydromorphone in patients with chronic cancer pain

This open-label, multicenter study assessed the efficacy and tolerability of conversion to once-daily OROS hydromorphone from previous opioid agonist therapy in patients with chronic cancer pain. Patients were stabilized on their previous therapy before conversion at a 5:1 ratio of morphine sulfate to hydromorphone hydrochloride. The OROS hydromorphone dose was titrated over 3 - 21 days to achieve effective analgesia and was maintained for up to 14 days. Efficacy was assessed using the Brief Pain Inventory (BPI). Adverse events and vital signs were monitored. Dose stabilization was achieved in 119 of the 127 (94%) patients who received the study medication; in 77%, stabilization was achieved with no titration steps. Mean BPI pain intensity ratings and BPI pain interference scores decreased significantly after OROS hydromorphone treatment compared with pretreatment values. Mean pain-relief level remained stable after conversion and throughout treatment with OROS hydromorphone. Adverse events were as expected for cancer patients receiving opioid agonists. There were no clinically significant changes in vital signs.

Endogenous opiates and behavior: 2006

This paper is the 29th consecutive installment of the annual review of research concerning the endogenous opioid system, now spanning 30 years of research. It summarizes papers published during 2006 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurological disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17).

Methadone for cancer pain

BACKGROUND

Methadone is an opioid used in the management of cancer pain. A particular role in neuropathic pain has been suggested. The quest for evidence based palliative care prompted a formal appraisal of methadone in comparison with other analgesics. This is an updated version of the original Cochrane review published in Issue 1, 2004.

OBJECTIVES

To determine effectiveness and safety of methadone analgesia in cancer pain patients.

SEARCH STRATEGY

MEDLINE, EMBASE, CancerLit, CINAHL and Cochrane databases were searched in 2002 using a strategy developed with the Cochrane Pain, Palliative and Supportive Care Group. Repeat searches were conducted in September 2006.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of methadone against active or placebo comparator in patients with cancer pain were included. Outcome measures sought were reduction in pain intensity, adverse effects, attrition, patient satisfaction and quality of life. There were no language restrictions.

DATA COLLECTION AND ANALYSIS

Eligible studies were selected with independent collaboration from a colleague. Full text was retrieved if any uncertainty about eligibility remained. Non-English texts were screened by Cochrane contacts. Quality assessment and data extraction were conducted using standardised data forms. Drug and placebo dose, titration, route and formulation were compared and detail of all outcome measures (if available) recorded.

MAIN RESULTS

This updated review includes nine RCTs (six double blinded, two crossover) with 459 recruits and 392 completing patients. All studies involved active opioid comparators (morphine, dextromoramide, pethidine, diamorphine with cocaine mixture) with different dose and titration schedules and various pain scoring scales. One study differentiated cases by pain syndrome. Few presented complete pain data sets but complete adverse events data were recorded in every study. Efficacy and tolerability were broadly similar between methadone and morphine. No useful meta-analysis has been possible.

AUTHORS' CONCLUSIONS

The updated review contains new information supporting the previous conclusions that methadone has similar analgesic efficacy to morphine. The additional study examined neuropathic and non-neuropathic pain, finding no superiority for methadone in the former group. The new study also addresses a clinically relevant concern about short term/single dose studies. Use beyond a few days may result in methadone accumulation leading to delayed onset of adverse effects. In an assessment over 28 days there was a higher rate of withdrawal due to side effects in the methadone group. This observation reinforces the advice that experienced clinicians should take responsibility for initiation and careful dose adjustment and monitoring of methadone.

Once-daily OROS hydromorphone for the management of chronic nonmalignant pain: a dose-conversion and titration study

BACKGROUND

The use of opioid analgesics for patients with chronic nonmalignant pain is becoming more widely accepted, and long-acting formulations are an important treatment option.

AIM

To assess conversion to extended-release OROS hydromorphone from previous stable opioid agonist therapy in patients with chronic nonmalignant pain of moderate-to-severe intensity.

METHODS

In this open-label multicentre trial, patients were stabilised on their previous opioid therapy before being switched to OROS hydromorphone at a ratio of 5 : 1 (morphine sulphate equivalent to hydromorphone hydrochloride). The OROS hydromorphone dose was titrated over 3-16 days to achieve effective analgesia, and maintenance treatment continued for 14 days.

RESULTS

Study medication was received by 336 patients; 66% completed all study phases. Stabilisation of OROS hydromorphone was achieved by 94.6% of patients, the majority in two or fewer titration steps (mean time, 4.2 days). Mean pain intensity scores, as determined by the Brief Pain Inventory, decreased during OROS hydromorphone treatment (p <or= 0.001). The percentage of patients rating their pain relief as 'good' or 'complete' increased, and the use of rescue analgesics for breakthrough pain decreased. The interference of pain with everyday activities (e.g. walking or work), and the effects on mood and enjoyment of life, also improved during the study (all p < 0.001). OROS hydromorphone was well tolerated, and adverse events were those expected for opioid agonist therapy.

CONCLUSION

Patients with chronic nonmalignant pain who had been receiving opioid therapy easily underwent conversion to OROS hydromorphone, with no loss of efficacy or increase in adverse events.