Patient-controlled analgesic infusions: alfentanil versus morphine

Pharmacological Treatment of Cancer Pain: Alternative Routes of Opioid Administration

Cancer-related pain is present in 51% of patients at various stages of the disease, and the incidence increases up to 74% in advanced and terminal stages. The World Health Organization proposed and issued very simple guidelines for the pharmacologic treatment of cancer-related pain. According to the guidelines, opioid analgesics are the mainstay of analgesic therapy, and the first choice for drug administration is considered to be the oral route. However, in some clinical situations, the oral route is not feasible, and analgesic drugs consequently have to be administered via an alternative route. For example, this is the case when the patient presents vomiting, bowel obstruction, severe dysphagia, mental confusion and when the opioid dose has to be increased drastically in order to achieve adequate pain control. This review of the literature is aimed at describing the indications, the limits and the main aspects of the pharmacokinetics and pharmacodynamics relative to the alternative routes of administration of opioids most commonly used in clinical practice. Sublingual, rectal, subcutaneous, intravenous, transdermal and spinal administration routes are examined.

Synthesis and Evaluation of 5-(o-Tolyl)-1H-tetrazole Derivatives as Potent Anticonvulsant Agents

A series of 5-(o-tolyl)-1H-tetrazole derivatives were synthesized and evaluated for their anticonvulsant activities. 1-(2-Methylbenzyl)-5-(o-tolyl)-1H-tetrazole (3h) showed important anticonvulsant activity against the MES-induced seizures, as well as lower neurotoxicity with an ED₅₀ value of 12.7 mg/kg and a TD₅₀ value of over 500 mg/kg after intraperitoneal injection into mice, providing 3h with a high protective index (TD₅₀ /ED₅₀ ) of over 39.4. The achieved results prove that the distinctive compounds could be valuable as a model for future development, adaptation, and investigation to construct more active analogues.

Oral morphine for cancer pain

BACKGROUND

This is the third updated version of a Cochrane review first published in Issue 4, 2003 of The Cochrane Library and first updated in 2007. Morphine has been used for many years to relieve pain. Oral morphine in either immediate release or modified release form remains the analgesic of choice for moderate or severe cancer pain.

OBJECTIVES

To determine the efficacy of oral morphine in relieving cancer pain, and to assess the incidence and severity of adverse events.

SEARCH METHODS

We searched the following databases: Cochrane Central Register of Controlled Trials (CENTRAL 2015, Issue 9); MEDLINE (1966 to October 2015); and EMBASE (1974 to October 2015). We also searched ClinicalTrials.gov (1 October 2015).

SELECTION CRITERIA

Published randomised controlled trials (RCTs) using placebo or active comparators reporting on the analgesic effect of oral morphine in adults and children with cancer pain. We excluded trials with fewer than 10 participants.

DATA COLLECTION AND ANALYSIS

One review author extracted data, which were checked by another review author. There were insufficient comparable data for meta-analysis to be undertaken or to produce numbers needed to treat (NNTs) for the analgesic effect. We extracted any available data on the number or proportion of participants with 'no worse than mild pain' or treatment success (very satisfied, or very good or excellent on patient global impression scales).

MAIN RESULTS

We identified seven new studies in this update. We excluded six, and one study is ongoing so also not included in this update. This review contains a total of 62 included studies, with 4241 participants. Thirty-six studies used a cross-over design ranging from one to 15 days, with the greatest number (11) for seven days for each arm of the trial. Overall we judged the included studies to be at high risk of bias because the methods of randomisation and allocation concealment were poorly reported. The primary outcomes for this review were participant-reported pain and pain relief.Fifteen studies compared oral morphine modified release (Mm/r) preparations with morphine immediate release (MIR). Fourteen studies compared Mm/r in different strengths; six of these included 24-hour modified release products. Fifteen studies compared Mm/r with other opioids. Six studies compared MIR with other opioids. Two studies compared oral Mm/r with rectal Mm/r. Three studies compared MIR with MIR by a different route of administration. Two studies compared Mm/r with Mm/r at different times and two compared MIR with MIR given at a different time. One study was found comparing each of the following: Mm/r tablet with Mm/r suspension; Mm/r with non-opioids; MIR with non-opioids; and oral morphine with epidural morphine.In the previous update, a standard of 'no worse than mild pain' was set, equivalent to a score of 30/100 mm or less on a visual analogue pain intensity scale (VAS), or the equivalent in other pain scales. Eighteen studies achieved this level of pain relief on average, and no study reported that good levels of pain relief were not attained. Where results were reported for individual participants in 17 studies, 'no worse than mild pain' was achieved by 96% of participants (362/377), and an outcome equivalent to treatment success in 63% (400/638).Morphine is an effective analgesic for cancer pain. Pain relief did not differ between Mm/r and MIR. Modified release versions of morphine were effective for 12- or 24-hour dosing depending on the formulation. Daily doses in studies ranged from 25 mg to 2000 mg with an average of between 100 mg and 250 mg. Dose titration was undertaken with both instant release and modified release products. A small number of participants did not achieve adequate analgesia with morphine. Adverse events were common, predictable, and approximately 6% of participants discontinued treatment with morphine because of intolerable adverse events.The quality of the evidence is generally poor. Studies are old, often small, and were largely carried out for registration purposes and therefore were only designed to show equivalence between different formulations.

AUTHORS' CONCLUSIONS

The conclusions have not changed for this update. The effectiveness of oral morphine has stood the test of time, but the randomised trial literature for morphine is small given the importance of this medicine. Most trials recruited fewer than 100 participants and did not provide appropriate data for meta-analysis. Only a few reported how many people had good pain relief, but where it was reported, over 90% had no worse than mild pain within a reasonably short time period. The review demonstrates the wide dose range of morphine used in studies, and that a small percentage of participants are unable to tolerate oral morphine. The review also shows the wide range of study designs, and inconsistency in cross-over designs. Trial design was frequently based on titration of morphine or comparator to achieve adequate analgesia, then crossing participants over in cross-over design studies. It was not clear if these trials were sufficiently powered to detect any clinical differences between formulations or comparator drugs. New studies added to the review for the previous update reinforced the view that it is possible to use modified release morphine to titrate to analgesic effect. There is qualitative evidence that oral morphine has much the same efficacy as other available opioids.

Oral morphine for cancer pain

BACKGROUND

This is the second updated version of a Cochrane review first published in Issue 4, 2003 of The Cochrane Library and first updated in 2007. Morphine has been used for many years to relieve pain. Oral morphine in either immediate release or modified release form remains the analgesic of choice for moderate or severe cancer pain.

OBJECTIVES

To determine the efficacy of oral morphine in relieving cancer pain, and assess the incidence and severity of adverse effects.

SEARCH METHODS

We searched the following databases: Cochrane Pain, Palliative and Supportive Care Group Trials Register (June 2013); Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 5, May); MEDLINE (1966 to June 2013); and EMBASE (1974 to June 2013).

SELECTION CRITERIA

Published randomised controlled trials (RCTs) using placebo or active comparators reporting on the analgesic effect of oral morphine in adults and children with cancer pain. Trials with fewer than ten participants were excluded.

DATA COLLECTION AND ANALYSIS

One review author extracted data, which were checked by another review author. There were insufficient comparable data for meta-analysis to be undertaken or to produce numbers needed to treat (NNTs) for the analgesic effect. We extracted any available data on the number or proportion of participants with 'no worse than mild pain' or treatment success (very satisfied, or very good or excellent on patient global impression scales).

MAIN RESULTS

Ten new studies (638 participants) were identified for this update, bringing the total of included studies to 62, with 4241 participants. Thirty-six studies used a cross-over design ranging from one to 15 days, with the greatest number (11) for seven days for each arm of the trial.Fifteen studies compared oral morphine modified release (Mm/r) preparations with morphine immediate release (MIR). Fourteen studies compared Mm/r in different strengths; six of these included 24-hour modified release products. Fifteen studies compared Mm/r with other opioids. Six studies compared MIR with other opioids. Two studies compared oral Mm/r with rectal Mm/r. Three studies compared MIR with MIR by a different route of administration. Two studies compared Mm/r with Mm/r at different times and two compared MIR with MIR given at a different time. One study was found comparing each of the following: Mm/r tablet with Mm/r suspension; Mm/r with non-opioids; MIR with non-opioids; and oral morphine with epidural morphine.In this update a standard of 'no worse than mild pain' was set equivalent to a score of 30/100 mm or less on a visual analogue pain intensity scale (VAS), or the equivalent in other pain scales. Eighteen studies achieved this level of pain relief on average, and no study reported that good levels of pain relief were not attained. Where results were reported for individual participants in 17 studies, 'no worse than mild pain' was achieved by 96% of participants (362/377), and an outcome equivalent to treatment success in 63% (400/638).Morphine is an effective analgesic for cancer pain. Pain relief did not differ between Mm/r and MIR. Modified release versions of morphine were effective for 12- or 24-hour dosing depending on the formulation. Daily doses in studies ranged from 25 mg to 2000 mg with an average of between 100 mg and 250 mg. Dose titration was undertaken with both instant release and modified release products. A small number of participants did not achieve adequate analgesia with morphine. Adverse effects were common and approximately 6% of participants discontinued treatment because of intolerable adverse effects.

AUTHORS' CONCLUSIONS

The effectiveness of oral morphine has stood the test of time, but the randomised trial literature for morphine is small given the importance of this medicine. Most trials recruited fewer than 100 participants and did not provide appropriate data for meta-analysis. Only a few reported how many people had good pain relief, but where it was reported, over 90% had no worse than mild pain within a reasonably short time period. The review demonstrates the wide dose range of morphine used in studies, and that a small percentage of participants are unable to tolerate oral morphine. The review also shows the wide range of study designs, and inconsistency in cross-over designs. Trial design was frequently based on titration of morphine or comparator to achieve adequate analgesia, then crossing participants over in cross-over design studies. It was not clear if these trials are sufficiently powered to detect any clinical differences between formulations or comparator drugs. New studies added to the review reinforce the view that it is possible to use modified release morphine to titrate to analgesic effect. There is qualitative evidence that oral morphine has much the same efficacy as other available opioids.

Systematic review of antimicrobials, mucosal coating agents, anesthetics, and analgesics for the management of oral mucositis in cancer patients

PURPOSE

The aim of this project was to develop clinical practice guidelines on the use of antimicrobials, mucosal coating agents, anesthetics, and analgesics for the prevention and management of oral mucositis (OM) in cancer patients.

METHODS

A systematic review of the available literature was conducted. The body of evidence for the use of each agent, in each setting, was assigned a level of evidence. Based on the evidence level, one of the following three guideline determinations was possible: recommendation, suggestion, or no guideline possible.

RESULTS

A recommendation was developed in favor of patient-controlled analgesia with morphine in hematopoietic stem cell transplant (HSCT) patients. Suggestions were developed in favor of transdermal fentanyl in standard dose chemotherapy and HSCT patients and morphine mouth rinse and doxepin rinse in head and neck radiation therapy (H&N RT) patients. Recommendations were developed against the use of topical antimicrobial agents for the prevention of mucositis. These included recommendations against the use of iseganan for mucositis prevention in HSCT and H&N RT and against the use of antimicrobial lozenges (polymyxin-tobramycin-amphotericin B lozenges/paste and bacitracin-clotrimazole-gentamicin lozenges) for mucositis prevention in H&N RT. Recommendations were developed against the use of the mucosal coating agent sucralfate for the prevention or treatment of chemotherapy-induced or radiation-induced OM. No guidelines were possible for any other agent due to insufficient and/or conflicting evidence.

CONCLUSION

Additional well-designed research is needed on prevention and management approaches for OM.

A systematic review of the use of opioid medication for those with moderate to severe cancer pain and renal impairment: a European Palliative Care Research Collaborative opioid guidelines project

BACKGROUND

Opioid use in patients with renal impairment can lead to increased adverse effects. Opioids differ in their effect in renal impairment in both efficacy and tolerability. This systematic literature review forms the basis of guidelines for opioid use in renal impairment and cancer pain as part of the European Palliative Care Research Collaborative's opioid guidelines project.

OBJECTIVE

The objective of this study was to identify and assess the quality of evidence for the safe and effective use of opioids for the relief of cancer pain in patients with renal impairment and to produce guidelines.

SEARCH STRATEGY

The Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, MedLine, EMBASE and CINAHL were systematically searched in addition to hand searching of relevant journals.

SELECTION CRITERIA

Studies were included if they reported a clinical outcome relevant to the use of selected opioids in cancer-related pain and renal impairment. The selected opioids were morphine, diamorphine, codeine, dextropropoxyphene, dihydrocodeine, oxycodone, hydromorphone, buprenorphine, tramadol, alfentanil, fentanyl, sufentanil, remifentanil, pethidine and methadone. No direct comparator was required for inclusion. Studies assessing the long-term efficacy of opioids during dialysis were excluded.

DATA COLLECTION AND ANALYSIS

This is a narrative systematic review and no meta-analysis was performed. The Grading of RECOMMENDATIONS Assessment, Development and Evaluation (GRADE) approach was used to assess the quality of the studies and to formulate guidelines.

MAIN RESULTS

Fifteen original articles were identified. Eight prospective and seven retrospective clinical studies were identified but no randomized controlled trials. No results were found for diamorphine, codeine, dihydrocodeine, buprenorphine, tramadol, dextropropoxyphene, methadone or remifentanil.

CONCLUSIONS

All of the studies identified have a significant risk of bias inherent in the study methodology and there is additional significant risk of publication bias. Overall evidence is of very low quality. The direct clinical evidence in cancer-related pain and renal impairment is insufficient to allow formulation of guidelines but is suggestive of significant differences in risk between opioids.

RECOMMENDATIONS

RECOMMENDATIONS regarding opioid use in renal impairment and cancer pain are made on the basis of pharmacokinetic data, extrapolation from non-cancer pain studies and from clinical experience. The risk of opioid use in renal impairment is stratified according to the activity of opioid metabolites, potential for accumulation and reports of successful or harmful use. Fentanyl, alfentanil and methadone are identified, with caveats, as the least likely to cause harm when used appropriately. Morphine may be associated with toxicity in patients with renal impairment. Unwanted side effects with morphine may be satisfactorily dealt with by either increasing the dosing interval or reducing the 24 hour dose or by switching to an alternative opioid.

Interventions for treating oral mucositis for patients with cancer receiving treatment

BACKGROUND

Treatment of cancer is increasingly effective but associated with short and long term side effects. Oral side effects, including oral mucositis (mouth ulceration), remain a major source of illness despite the use of a variety of agents to treat them.

OBJECTIVES

To assess the effectiveness of interventions for treating oral mucositis or its associated pain in patients with cancer receiving chemotherapy or radiotherapy or both.

SEARCH STRATEGY

Electronic searches of Cochrane Oral Health Group and PaPaS Trials Registers (to 1 June 2010), CENTRAL via The Cochrane Library (to Issue 2, 2010), MEDLINE via OVID (1950 to 1 June 2010), EMBASE via OVID (1980 to 1 June 2010), CINAHL via EBSCO (1980 to 1 June 2010), CANCERLIT via PubMed (1950 to 1 June 2010), OpenSIGLE (1980 to 1 June 2010) and LILACS via the Virtual Health Library (1980 to 1 June 2010) were undertaken. Reference lists from relevant articles were searched and the authors of eligible trials were contacted to identify trials and obtain additional information.

SELECTION CRITERIA

All randomised controlled trials comparing agents prescribed to treat oral mucositis in people receiving chemotherapy or radiotherapy or both. Outcomes were oral mucositis, time to heal mucositis, oral pain, duration of pain control, dysphagia, systemic infection, amount of analgesia, length of hospitalisation, cost and quality of life.

DATA COLLECTION AND ANALYSIS

Data were independently extracted, in duplicate, by two review authors. Authors were contacted for details of randomisation, blindness and withdrawals. Risk of bias assessment was carried out on six domains. The Cochrane Collaboration statistical guidelines were followed and risk ratio (RR) values calculated using fixed-effect models (less than 3 trials in each meta-analysis).

MAIN RESULTS

Thirty-two trials involving 1505 patients satisfied the inclusion criteria. Three comparisons for mucositis treatment including two or more trials were: benzydamine HCl versus placebo, sucralfate versus placebo and low level laser versus sham procedure. Only the low level laser showed a reduction in severe mucositis when compared with the sham procedure, RR 5.28 (95% confidence interval (CI) 2.30 to 12.13).Only 3 comparisons included more than one trial for pain control: patient controlled analgesia (PCA) compared to the continuous infusion method, therapist versus control, cognitive behaviour therapy versus control. There was no evidence of a difference in mean pain score between PCA and continuous infusion, however, less opiate was used per hour for PCA, mean difference 0.65 mg/hour (95% CI 0.09 to 1.20), and the duration of pain was less 1.9 days (95% CI 0.3 to 3.5).

AUTHORS' CONCLUSIONS

There is weak and unreliable evidence that low level laser treatment reduces the severity of the mucositis. Less opiate is used for PCA versus continuous infusion. Further, well designed, placebo or no treatment controlled trials assessing the effectiveness of interventions investigated in this review and new interventions for treating mucositis are needed.

Oral morphine for cancer pain

BACKGROUND

This is an updated version of a previous Cochrane review first published in Issue 4, 2003 of The Cochrane Library. Morphine has been used for many years to relieve pain. Oral morphine in either immediate release or modified release form remains the analgesic of choice for moderate or severe cancer pain.

OBJECTIVES

To determine the efficacy of oral morphine in relieving cancer pain and to assess the incidence and severity of adverse effects.

SEARCH STRATEGY

The following databases were searched: Cochrane Pain, Palliative and Supportive Care Group Trials Register (December 2006); Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2006, Issue 4); MEDLINE (1966 to December 2006); and EMBASE (1974 to December 2006).

SELECTION CRITERIA

Published randomised controlled trials (RCTs) reporting on the analgesic effect of oral morphine in adults and children with cancer pain. Any comparator trials were considered. Trials with fewer than ten participants were excluded.

DATA COLLECTION AND ANALYSIS

One review author extracted data, which was checked by the other review author. There were insufficient comparable data for meta-analysis to be undertaken or to produce numbers-needed-to-treat (NNT) for the analgesic effect.

MAIN RESULTS

In this update, nine new studies with 688 participants were added. Fifty-four studies (3749 participants) met the inclusion criteria. Fifteen studies compared oral modified release morphine (Mm/r) preparations with immediate release morphine (MIR). Twelve studies compared Mm/r in different strengths, five of these included 24-hour modified release products. Thirteen studies compared Mm/r with other opioids. Six studies compared MIR with other opioids. Two studies compared oral Mm/r with rectal Mm/r. Two studies compared MIR with MIR by a different route of administration. One study was found comparing each of the following: Mm/r tablet with Mm/r suspension; Mm/r with non-opioids; MIR with non-opioids; and oral morphine with epidural morphine. Morphine was shown to be an effective analgesic. Pain relief did not differ between Mm/r and MIR. Modified release versions of morphine were effective for 12 or 24-hour dosing depending on the formulation. Daily doses in studies ranged from 25 mg to 2000 mg with an average of between 100 mg and 250 mg. Dose titration were undertaken with both instant release and modified release products. Adverse effects were common but only 4% of patients discontinued treatment because of intolerable adverse effects.

AUTHORS' CONCLUSIONS

The randomised trial literature for morphine is small given the importance of this medicine. Most trials recruited fewer than 100 participants and did not provide appropriate data for meta-analysis. Trial design was frequently based on titration of morphine or comparator to achieve adequate analgesia, then crossing participants over in crossover design studies. It was not clear if these trials are sufficiently powered to detect any clinical differences between formulations or comparator drugs. Studies added to the review reinforce the view that it is possible to use modified release morphine to titrate to analgesic effect. There is qualitative evidence for effectiveness of oral morphine which compares well to other available opioids. There is limited evidence to suggest that transmucosal fentanyl provides more rapid pain relief for breakthrough pain compared to morphine.

Interventions for treating oral mucositis for patients with cancer receiving treatment

BACKGROUND

Treatment of cancer is increasingly effective but associated with short and long term side effects. Oral side effects, including oral mucositis (mouth ulceration), remain a major source of illness despite the use of a variety of agents to treat them.

OBJECTIVES

To assess the effectiveness of interventions for treating oral mucositis or its associated pain in patients with cancer receiving chemotherapy or radiotherapy or both.

SEARCH STRATEGY

Computerised searches of Cochrane Oral Health Group's Trials Register; Cochrane Pain, Palliative and Supportive Care Group's Trials Register; CENTRAL; MEDLINE and EMBASE were undertaken. Reference lists from relevant articles were searched and the authors of eligible trials were contacted to identify trials and obtain additional information. Date of the most recent searches June 2006: CENTRAL (The Cochrane Library 2006, Issue 2).

SELECTION CRITERIA

All randomised controlled trials comparing agents prescribed to treat oral mucositis in people receiving chemotherapy or radiotherapy or both. Outcomes were oral mucositis, time to heal mucositis, oral pain, duration of pain control, dysphagia, systemic infection, amount of analgesia, length of hospitalisation, cost and quality of life.

DATA COLLECTION AND ANALYSIS

Data were independently extracted, in duplicate, by two review authors. Authors were contacted for details of randomisation, blindness and withdrawals. Quality assessment was carried out on these three criteria. The Cochrane Oral Health Group statistical guidelines were followed and risk ratio (RR) values calculated using fixed effect models.

MAIN RESULTS

Twenty-six trials involving 1353 patients satisfied the inclusion criteria. Four agents, each in single trials, were found to be effective for improving (allopurinol RR 3.33, 95% confidence interval (CI) 1.06 to 10.49; granulocyte macrophage-colony stimulating factor RR 4.23, 95% CI 1.35 to 13.24; immunoglobulin RR 1.81, 95% CI 1.24 to 2.65; human placentral extract RR 4.50, 95% CI 2.29 to 8.86) or eradicating mucositis (allopurinol RR 19.00, 95% CI 1.17 to 307.63). Three of these trials were rated as at moderate risk of bias and one as at high risk of bias. The following agents were not found to be effective: benzydamine HCl, sucralfate, tetrachlorodecaoxide, chlorhexidine and 'magic' (lidocaine solution, diphenhydramine hydrochloride and aluminum hydroxide suspension). Six trials compared the time to heal and mucositis was found to heal more quickly with two interventions: granulocyte macrophage-colony stimulating factor when compared to povidone iodine, with mean difference -3.5 days (95% CI -4.1 to -2.9) and allopurinol compared to placebo, with mean difference -4.5 days (95% CI -5.8 to -3.2). Three trials compared patient controlled analgesia (PCA) to the continuous infusion method for controlling pain. There was no evidence of a difference, however, less opiate was used per hour for PCA, and the duration of pain was shorter. One trial demonstrated that pharmacokinetically based analgesia (PKPCA) reduced pain compared with PCA: however, more opiate was used with PKPCA.

AUTHORS' CONCLUSIONS

There is weak and unreliable evidence that allopurinol mouthwash, granulocyte macrophage-colony stimulating factor, immunoglobulin or human placental extract improve or eradicate mucositis. There is no evidence that patient controlled analgesia (PCA) is better than continuous infusion method for controlling pain, however, less opiate was used per hour, and duration of pain was shorter, for PCA. Further, well designed, placebo-controlled trials assessing the effectiveness of allopurinol mouthwash, granulocyte macrophage-colony stimulating factor, immunoglobulin, human placental extract, other interventions investigated in this review and new interventions for treating mucositis are needed.

The role of opioid receptor internalization and beta-arrestins in the development of opioid tolerance

Opioid tolerance, a phenomenon characterized by decreased analgesic effects obtained by the same dose of opioids after repeated use of the opioids, is a significant clinical problem. Traditional theory attributes receptor desensitization and internalization and post-receptor adaptation to the development of opioid tolerance. However, morphine, a commonly used opioid, induces tolerance but is not an effective drug to induce opioid receptor desensitization and internalization. Recent studies found that internalized opioid receptors can become competent receptors and recycle back to the cell surface membrane after dephosphorylation. Thus, receptor internalization may be a way to reduce opioid tolerance. Multiple studies have suggested a key role of beta-arrestins in opioid receptor desensitization and internalization and opioid tolerance. Although beta-arrestin 1 and beta-arrestin 2 are important for these effects induced by opioids with high intrinsic efficacy such as etorphine and fentanyl, morphine tolerance may be mediated mainly via beta-arrestin 2. Modification of opioid receptor internalization by affecting the interaction between opioid receptors and beta-arrestins may be a therapeutic target for reducing opioid tolerance.

A retrospective review of the use of alfentanil in a hospital palliative care setting

Alfentanil is becoming an alternative to diamorphine when parental opioids are required, especially in the presence of renal insufficiency. Its pharmacokinetic properties suggest that tolerance may be rapidly induced, whilst concomitant administration of drugs that interfere with the cytochrome P450 system may alter its metabolism. This retrospective audit looked at the use of subcutaneous alfentanil in a palliative care setting over a 21-month period. Forty-eight out of the 81 notes identified were available for analysis. Alfentanil was used for a median of 9 days (range 1-81) with median increase in dose of 80% (range 0-1125%). No significant correlation was found between duration of infusion and dose escalation. In addition no significant correlation was found between dose escalation and concomitant drugs that either inhibited or induced the P450 system. This is the first study to investigate the use of relatively long-term use of parenteral alfentanil. The results suggest that neither tolerance nor concomitant drug administration is of clinical significance in the dose escalation.

Clinical practice guidelines for the prevention and treatment of cancer therapy-induced oral and gastrointestinal mucositis

BACKGROUND

Oral and gastrointestinal (GI) mucositis can affect up to 100% of patients undergoing high-dose chemotherapy and hematopoietic stem cell transplantation, 80% of patients with malignancies of the head and neck receiving radiotherapy, and a wide range of patients receiving chemotherapy. Alimentary track mucositis increases mortality and morbidity and contributes to rising health care costs. Consequently, the Multinational Association of Supportive Care in Cancer and the International Society for Oral Oncology assembled an expert panel to evaluate the literature and to create evidence-based guidelines for preventing, evaluating, and treating mucositis.

METHODS

Thirty-six panelists reviewed literature published between January 1966 and May 2002. An initial meeting in January 2002 produced a preliminary draft of guidelines that was reviewed at a second meeting the same year. Thereafter, a writing committee produced a report on mucositis pathogenesis, epidemiology, and scoring (also included in this issue), as well as clinical practice guidelines.

RESULTS

Panelists created recommendations from higher levels of evidence and suggestions when evidence was of a lower level and there was a consensus regarding the interpretation of the evidence by the panel. Panelists identified gaps in evidence that made it impossible to recommend or not recommend use of specific agents.

CONCLUSIONS

Oral/GI mucositis is a common side effect of many anticancer therapies. Evidence-based clinical practice guidelines are presented as a benchmark for clinicians to use for routine care of appropriate patients and as a springboard to challenge clinical investigators to conduct high-quality trials geared toward areas in which data are either lacking or conflicting.

Interventions for treating oral mucositis for patients with cancer receiving treatment

BACKGROUND

Treatment of cancer is increasingly effective but associated with short and long-term side effects. Oral side effects, including oral mucositis (mouth ulceration), remain a major source of illness despite the use of a variety of agents to treat them.

OBJECTIVES

To assess the effectiveness of interventions for treating oral mucositis or its associated pain in patients with cancer receiving chemotherapy and/or radiotherapy.

SEARCH STRATEGY

Computerised searches of Cochrane Oral Health Group's Trials Register, CENTRAL, MEDLINE and EMBASE were undertaken. Reference lists from relevant articles were searched and the authors of eligible trials were contacted to identify trials and obtain additional information. Date of the most recent searches August 2003: (CENTRAL) (The Cochrane Library Issue 3, 2003).

SELECTION CRITERIA

All randomised controlled trials comparing agents prescribed to treat oral mucositis in people receiving chemotherapy and/or radiotherapy. Outcomes were oral mucositis, time to heal mucositis, oral pain, duration of pain control, dysphagia, systemic infection, amount of analgesia, length of hospitalisation, cost and quality of life.

DATA COLLECTION AND ANALYSIS

Data were independently extracted, in duplicate, by two reviewers. Authors were contacted for details of randomisation, blindness and withdrawals. Quality assessment was carried out on these three criteria. The Cochrane Oral Health Group statistical guidelines were followed and relative risk values calculated using fixed effect models.

MAIN RESULTS

Twenty-five trials involving 1292 patients satisfied the inclusion criteria. Three agents, each in single trials, were found to be effective for improving (allopurinol RR 3.33, 95% CI 1.06 to 10.49; immunoglobulin RR 1.81, 95% CI 1.24 to 2.65; human placentral extract RR 4.50, 95% CI 2.29 to 8.86) or eradicating mucositis (allopurinol RR 19.00, 95% CI 1.17 to 307.63). Two of these trials were rated as at moderate risk of bias and one as at high risk of bias. The following agents were not found to be effective: benzydamine HCl, sucralfate, tetrachlorodecaoxide, chlorhexidine and 'magic' (lidocaine solution, diphenhydramine hydrochloride and aluminum hydroxide suspension). Six trials compared the time to heal and mucositis was found to heal more quickly with two interventions: Granulocyte Macrophage-Colony Stimulating Factor when compared to povidone iodine, with mean difference -3.5 days (95% CI -4.1 to -2.9) and allopurinol compared to placebo, with mean difference -4.5 days (95% CI -5.8 to -3.2). Three trials compared patient controlled analgesia (PCA) to the continuous infusion method for controlling pain. There was no evidence of a difference, however, less opiate was used per hour for PCA, and the duration of pain was shorter. One trial demonstrated that pharmacokinetically based analgesia (PKPCA) reduced pain compared with PCA, however more opiate was used with PKPCA.

REVIEWERS' CONCLUSIONS

There is weak and unreliable evidence that allopurinol mouthwash, vitamin E, immunoglobulin or human placental extract improve or eradicate mucositis. There is no evidence that patient controlled analgesia (PCA) is better than continuous infusion method for controlling pain, however, less opiate was used per hour, and duration of pain was shorter, for PCA. Further, well designed, placebo-controlled trials assessing the effectiveness of allopurinol mouthwash, immunoglobulin, human placental extract, other interventions investigated in this review and new interventions for treating mucositis are needed.

Oral morphine for cancer pain

BACKGROUND

Morphine has been used to relieve pain for many years. Oral morphine in either immediate release or sustained release form remains the analgesic of choice for moderate or severe cancer pain.

OBJECTIVES

To determine the efficacy of oral morphine in relieving cancer pain. To assess the incidence and severity of adverse effects.

SEARCH STRATEGY

The following databases were searched: The Cochrane Central Register of Controlled Trials (CENTRAL), Cochrane Library, Issue 4, 2002; the trials register of the Cochrane Pain, Palliative and Supportive Care group (February 2002); MEDLINE 1966 to December 2002; EMBASE 1988 to December 2002; and the Oxford Pain Relief database 1950 to 1994.

SELECTION CRITERIA

Published randomised controlled trials (full reports) reporting on the analgesic effect of oral morphine in adults and children with cancer pain. Any comparator trials were considered. Trials with fewer than 10 subjects were excluded.

DATA COLLECTION AND ANALYSIS

One reviewer extracted data, and the findings were checked by two other reviewers. There were insufficient comparable data for meta-analysis to be undertaken, or to produce numbers-needed-to-treat (NNT) for the analgesic effect.

MAIN RESULTS

Forty five studies (3061 subjects) met the inclusion criteria. Fourteen studies compared oral sustained release morphine (MSR) preparations with immediate release morphine (MIR). Eight studies compared MSR and MSR in different strengths. Nine studies compared MSR with other opioids. Five studies compared MIR with other opioids. Two studies compared oral MSR with rectal MSR. One study was found comparing each of the following: MSR tablet with MSR suspension; MSR with MSR at different dose frequencies; MSR with non-opioids; MIR with non-opioids; oral morphine with epidural morphine; and MIR with MIR by a different route of administration. Morphine was shown to be an effective analgesic. Pain relief did not differ between MSR and MIR. Sustained release versions of morphine were effective for 12 or 24 hour dosing depending on the formulation. Adverse effects were common but only 4% of patients discontinued treatment because of intolerable adverse effects.

REVIEWER'S CONCLUSIONS

The randomised trial literature for morphine is small given the importance of this medicine. Most trials recruited fewer than 100 participants, and did not provide appropriate data for meta-analysis. Trial design was frequently based on titration of morphine or comparator to achieve adequate analgesia, then crossing subjects over in crossover design studies. It is not clear if these trials are sufficiently powered to detect any clinical differences between formulations or comparator drugs.

Target-controlled infusion systems: role in anaesthesia and analgesia

Drug delivery by target-controlled infusion (TCI) allows automatic adjustments of the infusion rate of a drug to maintain a desired target concentration. Since drug effect is more closely related to blood concentration than to infusion rate, drug delivery via TCI is capable of creating stable blood concentrations of intravenous anaesthetics and analgesics. In this article the concept and history of TCI are described. The rational administration of TCI requires an appropriate pharmacokinetic data set and knowledge of the concentration-effect relationship; therefore, general pharmacokinetic and pharmacodynamic aspects of intravenous anaesthetics and analgesics are also addressed. Intraoperative investigations have demonstrated that TCI drug delivery allows rapid titration to a desired effect. The use of TCI for postoperative analgesia is still experimental, but TCI can, in part, overcome the disadvantages associated with continuous infusions and patient-controlled analgesia regimens in the postoperative period. Although TCI is capable of creating stable blood concentrations, when the target concentration is changed the resulting effect correlates better with a theoretical effect site concentration. The efficacy of TCI systems that can perform effect-site steering are still to be explored.

Patient maintained alfentanil target-controlled infusion for analgesia during extracorporeal shock wave lithotripsy

PURPOSE

The purpose of this study was to determine whether alfentanil given by a pharmacokinetic-based target controlled infusion (TCI) system under patient control is a suitable analgesic technique for extracorporeal shock wave lithotripsy (ESWL).

METHODS

The design was an open, unblinded, noncomparative, prospective study. Forty outpatients undergoing ESWL were given patient maintained alfentanil TCI. Pain, nausea and sedation were assessed every 300 shocks. Vital signs were recorded every three minutes, pulse oximetry and electrocardiography being monitored continuously. Blood alfentanil concentration was measured for comparison with the predicted value.

RESULTS

Alfentanil consumption (median 1.34 mg, range 0.8-3.6) and measured levels following treatment (median 60 ng.ml-1, range 15.6-134.3) varied widely. The precision of the TCI system and the median prediction error (bias) were both 49%. The median of pain scores recorded during treatment was 4 (range 0-8). The median respiration rate was 15 bpm (range 10-23), three patients required oxygen (SaO2 < 92%) cardiovascular measurements were stable and there was no excessive sedation. The incidence of nausea was 15%. All patients were ready for hospital discharge within one hour following treatment.

CONCLUSIONS

Patient maintained alfentanil TCI provides good analgesia for ESWL in the majority of patients with little sedation. Respiratory depression is uncommon but supplementary oxygen should be given prophylactically. There is considerable interindividual variation in demand for alfentanil indicating the usefulness of the patient control method. The TCI system underestimated alfentanil blood concentrations but this did not affect its clinical usefulness.

Patient-controlled alfentanil. Target-controlled infusion for postoperative analgesia

We have compared the opioid effects of a patient-demand, target-controlled infusion of alfentanil (n = 10), with patient-controlled bolus administration of morphine (n = 10) following major spinal surgery in Chinese patients aged from 11 to 67 years. The same general anaesthesia regimen was used in all patients. One group of patients were given intra-operative morphine analgesia followed by postoperative intravenous morphine patient-controlled analgesia, while the other group received an intra-operative target-controlled infusion of alfentanil. Following surgery, the alfentanil group were given control of a handset and were able to increase the target alfentanil plasma level in 5 ng.ml-1 increments with a 2-min lockout interval. If analgesia was not demanded within a 15-min period, the computer reduced the target concentration by 5 ng.ml-1. All patients had continuous pulse oximetry monitoring and hourly recording of pain, sedation, nausea scores and respiratory rate. Patients receiving alfentanil had the target concentration noted hourly and four blood samples taken during the first 24 h for measurement of plasma alfentanil concentrations by high performance liquid chromatography. The alfentanil infusion system was equally effective as an analgesic technique when compared with morphine patient-controlled analgesia. There were no hypoxaemic episodes (oxygen saturation < 94%), no difference in sedation scores and the incidence of nausea (30%) was the same in both groups. There was a significantly (p < 0.001) lower respiratory rate in the alfentanil group compared with patients receiving morphine at, clinically assessed, equianalgesia. The predicted plasma alfentanil concentrations increased rapidly from about 30 ng.ml-1 during the first 4 h to around 100 ng.ml-1 at the end of the 24-h study period. The precision of the target-controlled infusion system was 75.4% and the mean prediction error (bias) 58.1%, suggesting an underestimation of the measured alfentanil concentrations by the alfentanil infusion system in these Chinese patients.

Long-term opioid therapy: assessment of consequences and risks

Medical practice with respect to the use of opioids for the treatment of pain has been heavily influenced by societal perceptions of problems of addiction and by laws governing the use of opioids. To effectively use opioids for the treatment of chronic pain, physicians must recognize pervasive, but clinically often irrelevant societal and legal influences on prescribing, while at the same time respecting opioid properties which may lead to unwanted consequences in the course of opioid therapy. This paper reviews history and legislation that has shaped medical prescribing of opioids, examines the potential risks and consequences of long-term opioid therapy and assesses three models of long-term opioid therapy.

A pharmacokinetic approach to resolving spinal and systemic contributions to epidural alfentanil analgesia and side-effects

A pilot study was conducted in 7 normal volunteers to demonstrate the feasibility of employing pharmacokinetic tailoring to achieve matching plasma opioid concentration-time curves after epidural (e.p.) and intravenous (i.v.) alfentanil administration. Each subject participated in 1 pretest and 2 test sessions. Our pain model was cutaneous electrical stimulation of the finger and toe, adjusted to produce a baseline pain report of 5 (strong pain on a 0-5 scale). On test day 1, subjects received e.p. alfentanil (750 micrograms) and an i.v. saline infusion. Serial measurements of analgesia, end tidal CO2, pupil size, subjective side effects, and plasma alfentanil concentrations were conducted before and at various time intervals over a 4-h period after alfentanil administration. On test day 2, subjects received e.p. saline and a pharmacokinetically tailored i.v. infusion (using individual pharmacokinetics determined on the pretest day) designed to achieve a plasma concentration-time profile identical to that observed on the epidural day. The same battery of effect measurements was administered as on the 1st test day. Plasma alfentanil was measured to verify the accuracy of the tailored infusion. Plasma alfentanil concentration profiles were nearly identical on both test days. Peak plasma alfentanil concentrations were near the reported minimum effective analgesic concentration (MEAC). Overall, analgesia was slightly greater with e.p. administration. Onset of pain relief was rapid, and duration was approximately 1.5 h with e.p. and 1 h with i.v. alfentanil. There were no differences in pupil size, ETCO2, or subjective side effects between e.p. versus i.v. administration. We conclude that systemic redistribution from the epidural space appears to account for most, but not all, of the analgesia.

New developments in patient-controlled postoperative analgesia

Patient-controlled analgesia (PCA) is a newer technique for pain management. Patients are allowed to self-administer small analgesic bolus doses into a running intravenous infusion, intramuscularly, subcutaneously or even into the epidural space. Demands are usually controlled by computer-driven infusion pumps, but can also be delivered by disposable devices. Clinical experience demonstrates that individual variability in pain sensitivity and analgesic needs are of utmost importance. In contrast to earlier expectations, opioid consumption is usually higher than with restrictive conventional dosing regimes, but without an increase in serious side effects. Patients' acceptance is generally enthusiastic because of the possibility of self-control. PCA has proved its importance for pain studies, e.g. for algesimetry, to determine predictors of postoperative pain, to describe drug interactions, to evaluate the concept of pre-emptive analgesia or for pharmacokinetic designs. It is concluded that PCA results have been urgently required in order to change the mind of physicians and nursing staff with respect to individual pain management strategies. Once this goal is achieved, PCA concepts should also be used for the improvement of more conventional techniques.

Overview of current development in patient-controlled analgesia

Over the past two decades, numerous trials have assessed the safety and efficacy of patient-controlled analgesia (PCA). Advantages over conventional parenteral narcotics reported from these trials include equivalent to superior pain relief, superior patient satisfaction, decreased sedation and anxiety, faster return to normal functional status, and reduction in nursing time and hospitalization. The majority of these trials have been conducted in the postoperative patient population. In the mid to late 1980s, interest arose in applying PCA technology to the management of cancer pain. Factors that served as an impetus for the use of PCA in cancer pain included favorable reports from the postoperative setting and the often-cited statistics regarding the magnitude of the cancer pain problem. Advances in PCA technology coupled with advances in vascular access technology that allow the placement of long-term ports and catheters to facilitate intravenous, epidural, or intrathecal administration of opioid analgesics have made the applicability of PCA in ambulatory cancer patients an attractive option. The greatest breakthrough in PCA technology came with the introduction of devices making it possible to choose between intermittent (demand bolus) and continuous administration (continuous infusion) or both intermittent and continuous modes. A comparison of these types of PCA devices is described. The limitations of the literature involving PCA therapy in cancer patients make it difficult to identify optimal patient selection criteria, PCA administration schedules, drug selection and dosing, and optimal route of administration. The current status and pertinent issues related to these topics are addressed.

Management of orofacial pain in cancer patients

Pain in patients with cancer may arise due to the primary disease, or due to therapy of the malignant disease. Pain may be caused by oral infection, oral mucositis, and by alteration in musculoskeletal and neurological function. The management of orofacial and oropharyngeal pain in patients with cancer is reviewed in this paper.

[Perioperative analgesia in adults : The concept of balanced analgesia.]

The spectrum of perioperative pain treatment is discussed in the present review. The analgesic efficacy of various drugs and the dosage methods of administration and side effects reported for them in such reference works as the practical guide on the management of acute pain recently published by the International Association for the Study of Pain (IASP) are described. Effective postoperative analgesia can diminish stress reactions following surgery. Recovery and physical mobilization are improved as the result of adequate treatment. Results obtained in recent studies have demonstrated that primary adaptive hyperalgesia in the peripheral nociceptive area may develop into secondary maladaptive hypersensibility with a high degree of nociceptive excitability and pain. Chronic pain can develop following acute alterations. Increasing nociceptive activity of primary afferents induces alterations in the dorsal horn of the spinal cord. These alterations imply an increase in the excitability of nociceptive neurons, which has been described as neuronal plasticity. Clinical results have demonstrated prevention or delay of acute postoperative pain after injection of local anaesthetics, analgesic premedication or epidural injection of opioids just before the start of surgery. Continuous perioperative spinal analgesia has contributed significantly to the prevention of phantom limb pain in patients undergoing amputation of extremities. The development of pain memory may be prevented as a result of effective acute pain treatment. Several changes to the terminology of acute pain treatment for animal and clinical studies have recently been proposed, including such new terms as preemptive analgesia and pain prevention, which indicate new strategies in the treatment of postoperative pain. The concept of balanced analgesia refers to a strategy for the improvement of analgesic efficacy as a result of a combination of drugs with different local actions on nociception. The combination of systemic analgesics (opioids in low dosages) with nonsteroidal analgesics (e.g. diclofenac or ketorolac) and the combination of regional analgesic procedures with opioids have been shown to be very effective. The peripheral action of morphine offers new options in pain therapy. Different regional analgesic techniques and continuous infusions of local analgesics are described. The synergistic action of low dosages of local anaesthetics (bupivacaine 0.006%) with low dosages of fentanyl 0.0001-0.0002% are of interest for the treatment of obstetric pain and for pain in opioid-tolerant patients. Investigations performed by the author of this review have shown that epidural infusion of highly diluted mixtures of bupivacaine/fentanyl is highly effective in the analgesic treatment of patients undergoing prostatectomy, providing excellent physical mobilization. The potential dangers of drug combinations and contraindications are also discussed. The concept of using balanced analgesia to induce additive or synergistic effects following the administration of analgesic drugs requires further clinical studies.