Morphine-sparing effect of diclofenac in cancer pain

Opioid analgesics for nociceptive cancer pain: A comprehensive review

Pain is one of the most burdensome symptoms in people with cancer, and opioid analgesics are considered the mainstay of cancer pain management. For this review, the authors evaluated the efficacy and toxicities of opioid analgesics compared with placebo, other opioids, nonopioid analgesics, and nonpharmacologic treatments for background cancer pain (continuous and relatively constant pain present at rest), and breakthrough cancer pain (transient exacerbation of pain despite stable and adequately controlled background pain). They found a paucity of placebo-controlled trials for background cancer pain, although tapentadol or codeine may be more efficacious than placebo (moderate-certainty to low-certainty evidence). Nonsteroidal anti-inflammatory drugs including aspirin, piroxicam, diclofenac, ketorolac, and the antidepressant medicine imipramine, may be at least as efficacious as opioids for moderate-to-severe background cancer pain. For breakthrough cancer pain, oral transmucosal, buccal, sublingual, or intranasal fentanyl preparations were identified as more efficacious than placebo but were more commonly associated with toxicities, including constipation and nausea. Despite being recommended worldwide for the treatment of cancer pain, morphine was generally not superior to other opioids, nor did it have a more favorable toxicity profile. The interpretation of study results, however, was complicated by the heterogeneity in the study populations evaluated. Given the limited quality and quantity of research, there is a need to reappraise the clinical utility of opioids in people with cancer pain, particularly those who are not at the end of life, and to further explore the effects of opioids on immune system function and quality of life in these individuals.

A Survey of the Status of Methadone Switching in Japan Using a Hospital-Based Administrative Claims Database

Methadone is generally used for the management of cancer pain in patients who cannot obtain adequate analgesia from other strong opioids; however, it has a complicated and inconsistent conversion ratio from pre-switching opioid dosage to methadone. This issue may be pronounced in Japan because only oral tablets are commercially available. We aimed to elucidate the status of methadone switching in Japan, focusing on its dosage. Using a Japanese hospital-based administrative claims database, we included patients who switched to methadone between April 2008 and January 2021. The proportion of methadone switching completion that required more than the defined conversion ratio in the Japanese package insert (called "high-dose methadone switching") was evaluated as a primary endpoint. Other endpoints included "the duration from initiation to completion of methadone switching" and "factors affecting high-dose methadone switching by using multivariate logistic regression analysis". Of 1585 patients who received methadone, 370 were enrolled. Among those, 130 (35.1%) received high-dose methadone switching. The median duration of methadone switching completion (12 days) was longer in the high-dose methadone switching group than in other patients. Four variables were identified as factors affecting high-dose methadone switching. Younger age and outpatient status increased the risk of requiring high-dose methadone switching, whereas the concomitant use of nonsteroidal anti-inflammatory drugs and fentanyl as a pre-switching opioid decreased the risk. In conclusion, more than 30% of the patients underwent high-dose methadone switching and required long completion periods, suggesting that methadone switching remains challenging in Japan.

Revision of Pharmacological Treatment Recommendations for Cancer Pain: Clinical Guidelines from the Japanese Society of Palliative Medicine

Background: Pain is one of the most common symptoms in cancer patients. The Japanese Society for Palliative Medicine (JSPM) first published its clinical guidelines for the management of cancer pain in 2010. Since then, more research on cancer pain management has been reported, and new drugs have become available in Japan. Thus, the JSPM has now revised the clinical guidelines using a validated methodology. Methods: This guideline was developed through a systematic review, discussion, and the Delphi method, following a formal guideline development process. Results: Thirty-five recommendations were created: 19 for the pharmacological management of cancer pain, 6 for the management of opioid-induced adverse effects, and 10 for pharmacological treatment procedures. Due to the lack of evidence that directly addressed our clinical questions, most of the recommendations had to be based on consensus among committee members and other guidelines. Discussion: It is critical to continue to build high-quality evidence in cancer pain management, and revise these guidelines accordingly.

Oncologic Emergencies: Palliative Care in the Emergency Department Setting

BACKGROUND

Palliative care is an essential component of emergency medicine, as many patients with terminal illness will present to the emergency department (ED) for symptomatic management at the end of life (EOL).

OBJECTIVE

This narrative review evaluates palliative care in the ED, with a focus on the literature behind management of EOL symptoms, especially dyspnea and cancer-related pain.

DISCUSSION

As the population ages, increasing numbers of patients present to the ED with severe EOL symptoms. An understanding of the role of palliative care in the ED is crucial to effectively communicating with these patients to determine their goals and provide medical care in line with their wishes. Beneficence, nonmaleficence, and patient autonomy are essential components of palliative care. Patients without medical decision-making capacity may have an advance directive, do not resuscitate or do not intubate order, or Portable Medical Orders for Life-Sustaining Treatment available to assist clinicians. Effective and empathetic communication with patients and families is vital to EOL care discussions. Two of the most common and distressing symptoms at the EOL are dyspnea and pain. The most effective treatment of EOL dyspnea is opioids, with literature showing little efficacy for other therapies. The most effective treatment for cancer-related pain is opioids, with expeditious pain control achievable with a rapid fentanyl titration. It is also important to address nausea, vomiting, and secretions, as these are common at the EOL.

CONCLUSIONS

Emergency clinicians play a vital role in EOL patient care. Clear, empathetic communication and treatment of EOL symptoms are essential.

Nonsteroidal anti-inflammatory drugs and pain in cancer patients: a systematic review and reappraisal of the evidence

BACKGROUND

Emerging data highlights the potential role of cyclooxygenase (COX) inhibitors in the primary prevention of malignancy, reducing metastatic spread and improving overall mortality. Despite nonsteroidal anti-inflammatory drugs (NSAIDs) forming a key component of the WHO analgesic ladder, their use in cancer pain management remains relatively low. This review re-appraises the current evidence regarding the efficacy of COX inhibitors as analgesics in cancer pain, providing a succinct resource to aid clinicians' decision making when determining treatment strategies.

METHODS

Medline® and Embase® databases were searched for publications up to November 2018. Randomised controlled trials (RCTs) and double-blind controlled studies considering the use of NSAIDs for management of cancer-related pain in adults were included. Animal studies, case reports, and retrospective observational data were excluded.

RESULTS

Thirty studies investigating the use of NSAIDs in cancer pain management were identified. There is a lack of high-quality evidence regarding the analgesic efficacy of NSAIDs in cancer pain, with short study durations and heterogeneity in outcome measures limiting the ability to draw meaningful conclusions.

CONCLUSIONS

Despite the renewed interest in these cost-effective, well-established medications in cancer treatment outcomes, there is a paucity of data from the past 15 yr regarding their efficacy in cancer pain management. However, when analgesic strategies in the cancer population are being formulated, it is important that the potential benefits of this class of drug are considered. Further work investigating the role of NSAIDs in cancer pain management is undoubtedly warranted.

Characterisation and optimisation of diclofenac sodium orodispersible thin film formulation

Oral Thin Film (OTF) is a newly emerging drug delivery system which has many benefits for patients. Although there has been some formulation of OTF products, these have mainly been as confectionary or dental health products. The most significant benefit of this dosage format will only be realised once more pharmaceutical products become available. Within this paper, OTF strips containing Diclofenac Sodium were prepared using the solvent casting method and then characterised to ensure the method could conform to acceptable levels of uniformity, the mean (SD) diclofenac sodium content was 25.43 (1.39) mg, range 22.84-27.44 mg. Bioburden was tested against coliforms, yeasts and moulds and all results were confirmed to be <10 CFU/g, also similar dissolution profile when compared to a commercial product to ensure biowaiver. An acceptable level of uniformity of mass was produced. K-F titration was employed to reduce the water content of the strips and it was found to be acceptable, this represented a level of water which would not be viable for microbial growth. The technique employed here in the production of OTF resulted in high quality products and amenability to being up scaled. Furthermore, the characterisation method was also sufficient to assess the quality of the products and may be used for future analysis of OTF pharmaceuticals.

Systematic review and meta-analysis on non-opioid analgesics in palliative medicine

Non-opioid analgesics are widely used for pain relief in palliative medicine. However, there is a lack of evidence-based recommendations addressing the efficacy, tolerability, and safety of non-opioids in this field. A comprehensive systematic review and meta-analysis on current evidence can provide a basis for sound recommendations in clinical practice. A database search for controlled trials on the use of non-opioids in adult palliative patients was performed in Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, PsycINFO, and EMBASE from inception to 18 February 2018. Endpoints were pain intensity, opioid-sparing effects, safety, and quality of life. Studies with similar patients, interventions, and outcomes were included in the meta-analyses. Our systematic search was able to only identify studies dealing with cancer pain. Of 5991 retrieved studies, 43 could be included (n = 2925 patients). There was no convincing evidence for satisfactory pain relief by acetaminophen alone or in combination with strong opioids. We found substantial evidence of moderate quality for a satisfactory pain relief in cancer by non-steroidal anti-inflammatory drugs (NSAIDs), flupirtine, and dipyrone compared with placebo or other analgesics. There was no evidence for a superiority of one specific non-opioid. There was moderate quality of evidence for a similar pain reduction by NSAIDs in the usual dosage range compared with up to 15 mg of morphine or opioids of equianalgesic potency. The combination of NSAID and step III opioids showed a beneficial effect, without a decreased tolerability. There is scarce evidence concerning the combination of NSAIDs with weak opioids. There are no randomized-controlled studies on the use of non-opioids in a wide range of end-stage diseases except for cancer. Non-steroidal anti-inflammatory drugs, flupirtine, and dipyrone can be recommended for the treatment of cancer pain either alone or in combination with strong opioids. The use of acetaminophen in the palliative setting cannot be recommended. Studies are not available for long-term use. There is a lack of evidence regarding pain treatment by non-opioids in specific cancer entities.

Subcutaneous or intravenous opioid administration by patient-controlled analgesia in cancer pain: a systematic literature review

CONTEXT

Opioids administered by various routes are a mainstay of tumour-related pain management. Subcutaneous or intravenous patient-controlled analgesia (PCA) with opioids is an appropriate and safe form of treatment for postoperative pain but studies on this form of administration are sparse in the setting of cancer pain despite widespread use.

OBJECTIVE

To evaluate the published studies on opioids administered by subcutaneous and intravenous patient-controlled analgesia for patients with cancer pain.

METHODS

Articles were identified from the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 7, 2016), PubMed (Medline; 1975 to 2016) and EMBASE (1974 to 2016). Additional reports were identified from the reference lists of retrieved papers. Studies based on original data with a focus on intravenous or subcutaneous PCA administration of opioids in patients suffering from cancer-related pain were selected. The language was restricted to Dutch, English or German. Predefined information was extracted depending on the topic.

RESULTS

Fifty studies published since 1980 met the inclusion criteria. A wide range of study designs, study quality and research objectives were observed. The studies indicated use of standard or by proxy PCA in the inpatient and outpatient setting were safe and useful while significant adverse effects were rarely observed.

CONCLUSION

This systematic review of the current evidence suggests PCA can be appropriately used in a wide range of clinical situations.

Oral nonsteroidal anti-inflammatory drugs (NSAIDs) for cancer pain in adults

BACKGROUND

Pain is a common symptom with cancer, and 30% to 50% of all people with cancer will experience moderate to severe pain that can have a major negative impact on their quality of life. Non-opioid drugs are commonly used to treat cancer pain, and are recommended for this purpose in the World Health Organization (WHO) cancer pain treatment ladder, either alone or in combination with opioids.A previous Cochrane review that examined the evidence for nonsteroidal anti-inflammatory drugs (NSAIDs) or paracetamol, alone or combined with opioids, for cancer pain was withdrawn in 2015 because it was out of date; the date of the last search was 2005. This review, and another on paracetamol, updates the evidence.

OBJECTIVES

To assess the efficacy of oral NSAIDs for cancer pain in adults, and the adverse events reported during their use in clinical trials.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase from inception to April 2017, together with reference lists of retrieved papers and reviews, and two online study registries.

SELECTION CRITERIA

We included randomised, double-blind, single-blind, or open-label studies of five days' duration or longer, comparing any oral NSAID alone with placebo or another NSAID, or a combination of NSAID plus opioid with the same dose of the opioid alone, for cancer pain of any pain intensity. The minimum study size was 25 participants per treatment arm at the initial randomisation.

DATA COLLECTION AND ANALYSIS

Two review authors independently searched for studies, extracted efficacy and adverse event data, and examined issues of study quality and potential bias. We did not carry out any pooled analyses. We assessed the quality of the evidence using GRADE and created a 'Summary of findings' table.

MAIN RESULTS

Eleven studies satisfied inclusion criteria, lasting one week or longer; 949 participants with mostly moderate or severe pain were randomised initially, but fewer completed treatment or had results of treatment. Eight studies were double-blind, two single-blind, and one open-label. None had a placebo only control; eight compared different NSAIDs, three an NSAID with opioid or opioid combination, and one both. None compared an NSAID plus opioid with the same dose of opioid alone. Most studies were at high risk of bias for blinding, incomplete outcome data, or small size; none was unequivocally at low risk of bias.It was not possible to compare NSAIDs as a group with another treatment, or one NSAID with another NSAID. Results for all NSAIDs are reported as a randomised cohort. We judged results for all outcomes as very low-quality evidence.None of the studies reported our primary outcomes of participants with pain reduction of at least 50%, and at least 30%, from baseline; participants with Patient Global Impression of Change (PGIC) of much improved or very much improved (or equivalent wording). With NSAID, initially moderate or severe pain was reduced to no worse than mild pain after one or two weeks in four studies (415 participants in total), with a range of estimates between 26% and 51% in individual studies.Adverse event and withdrawal reporting was inconsistent. Two serious adverse events were reported with NSAIDs, and 22 deaths, but these were not clearly related to any pain treatment. Common adverse events were thirst/dry mouth (15%), loss of appetite (14%), somnolence (11%), and dyspepsia (11%). Withdrawals were common, mostly because of lack of efficacy (24%) or adverse events (5%).

AUTHORS' CONCLUSIONS

There is no high-quality evidence to support or refute the use of NSAIDs alone or in combination with opioids for the three steps of the three-step WHO cancer pain ladder. There is very low-quality evidence that some people with moderate or severe cancer pain can obtain substantial levels of benefit within one or two weeks.

Modulation of Nav1.8 by Lysophosphatidic Acid in the Induction of Bone Cancer Pain

Given that lysophosphatidic acid (LPA) and the tetrodotoxin-resistant sodium channel Nav1.8 are both involved in bone cancer pain, the present study was designed to investigate whether crosstalk between the LPA receptor LPA1 (also known as EDG2) and Nav1.8 in the dorsal root ganglion (DRG) contributes to the induction of bone cancer pain. We showed that the EDG2 antagonist Ki16198 blocked the mechanical allodynia induced by intrathecal LPA in naïve rats and attenuated mechanical allodynia in a rat model of bone cancer. EDG2 and Nav1.8 expression in L4-6 DRGs was upregulated following intrathecal or hindpaw injection of LPA. EDG2 and Nav1.8 expression in ipsilateral L4-6 DRGs increased with the development of bone cancer. Furthermore, we showed that EDG2 co-localized with Nav1.8 and LPA remarkably enhanced Nav1.8 currents in DRG neurons, and this was blocked by either a protein kinase C (PKC) inhibitor or a PKCε inhibitor. Overall, we demonstrated the modulation of Nav1.8 by LPA in DRG neurons, and that this probably underlies the peripheral mechanism by which bone cancer pain is induced.

WITHDRAWN: NSAIDS or paracetamol, alone or combined with opioids, for cancer pain

This review is out of date, although it is correct at the date of publication. The review may be misleading as new studies could alter the original conclusions. All previous versions of the review can be found in the ‘Other versions’ tab. A new author team intends to develop four new reviews on this topic, which will serve to update and supersede this review. The new reviews will cover paracetamol, paracetamol plus opioids, NSAIDs, and NSAIDs plus opioids, for cancer pain. For more information, contact the PaPaS Review Group.

The editorial group responsible for this previously published document have withdrawn it from publication.

Intravenous paracetamol infusion: Superior pain management and earlier discharge from hospital in patients undergoing palliative head-neck cancer surgery

Background:

Paracetamol; a cyclooxygenase inhibitor; acts through the central nervous system as well as serotoninergic system as a nonopioid analgesic. A prospective, double-blinded, and randomized-controlled study was carried out to compare the efficacy of preoperative 1g intravenous (iv) paracetamol with placebo in providing postoperative analgesia in head-neck cancer surgery.

Materials and Methods:

From 2008 February to 2009 December, 80 patients for palliative head-neck cancer surgery were randomly divided into (F) and (P) Group receiving ivplacebo and iv paracetamol, respectively, 5 min before induction. Everybody received fentanyl before induction and IM diclofenac for pain relief at8 hourly for 24 h after surgery. Visual analogue scale (VAS) and amount of fentanyl were measured for postoperative pain assessment (24 h).

Results and Statistical analysis:

The mean VAS score in 1^st, 2^nd postoperative hour, and fentanyl requirement was less and the need for rescue analgesic was delayed in ivparacetamol group which were all statistically significant. Paracetamol group had a shorter surgical intensive care unit (SICU) and hospital stay which was also statistically significant.

Conclusion:

The study demonstrates the effectiveness of ivparacetamol as preemptive analgesic in the postoperative pain control after head-neck cancer surgery and earlier discharge from hospital.

Nonopioid Drugs in the Treatment of Cancer Pain

The WHO analgesic ladder for the treatment of cancer pain provides a three-step sequential approach for analgesic administration based on pain severity that has global applicability. Nonopioids were recommended for mild pain, with the addition of mild opioids for moderate pain and strong opioids for severe pain. Here, we review the evidence for the use of nonopioid analgesic agents in patients with cancer and describe the mode of action of the main drug classes. Evidence supports the use of anti-inflammatory drugs such as acetaminophen/paracetamol and nonsteroidal anti-inflammatory drugs (NSAIDs) for mild cancer pain. Adding an NSAID to an opioid for stronger cancer pain is efficacious, but the risk of long-term adverse effects has not been quantified. There is limited evidence to support using acetaminophen with stronger opioids. Corticosteroids have a specific role in spinal cord compression and brain metastases, where improved analgesia is a secondary benefit. There is limited evidence for adding corticosteroids to stronger opioids when pain control is the primary objective. Systematic reviews suggest a role for antidepressant and anticonvulsant medications for neuropathic pain, but there are methodologic issues with the available studies. Bisphosphonates improve pain in patients with bony metastases in some tumor types. Denosumab may delay worsening of pain compared with bisphosphonates. Larger studies of longer duration are required to address outstanding questions concerning the use of nonopioid analgesia for stronger cancer pain.

The role of paracetamol and nonsteroidal anti-inflammatory drugs in addition to WHO Step III opioids in the control of pain in advanced cancer. A systematic review of the literature

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) and paracetamol are used widely in the management of mild to moderate cancer pain and are frequently combined with opioids in the treatment of moderate to severe pain.

AIM

To perform a systematic literature review of the evidence of the efficacy and toxicity of NSAIDs or paracetamol added to WHO Step III opioid treatment for cancer pain.

DESIGN AND DATA SOURCES

A systematic literature review of MedLine, EMBASE and Cochrane Central register of controlled trials database was carried out using both text words and MeSH/EMTREE terms.

RESULTS

Seven eligible papers were retrieved from the new search and five from the Cochrane review. Five of seven studies showed an additive effect of NSAIDs when combined with opioids either by improving analgesia (three studies) or by reducing the opioid dose (two studies). Paracetamol was only marginally effective in one of five trials. The study designs were not adequate to assess differences in side effects between the opioids alone and opioids in combination with NSAIDs or paracetamol.

CONCLUSIONS

The evidence from the available clinical trials is of limited amount and quality, but it weakly supports the proposal that the addition of an NSAIDs to WHO Step III opioids can improve analgesia or reduce opioid dose requirement. There is insufficient evidence to support the use of paracetamol in combination with Step III opioids. Data on the toxicity of NSAIDs in this indication are insufficient owing to the small number of patients and the short duration of treatment reported in the studies.

Dosage plan of a flurbiprofen injection product using inhibition of protein binding by lipid emulsion in rats

Flurbiprofen-axetil (FP-ax), a bolus injection product of a non-steroidal anti-inflammatory drug (NSAID), is a prodrug of flurbiprofen, an NSAID. As flurbiprofen strongly binds to site II of human serum albumin (HSA), the free (unbound) concentration of flurbiprofen after injection of FP-ax is low. We have examined the inhibitory effect of free fatty acid (FFA), a binding inhibitor for site II of HSA, on the binding of flurbiprofen in-vitro and in-vivo by ultrafiltration, to establish an effective dosage of FP-ax. In-vitro, fatty acid mixtures (FAs) inhibited the binding of flurbiprofen to rat serum albumin. The free fraction of flurbiprofen was remarkably increased by FAs in rat serum. In-vivo, FP-ax was injected into a control group (low FFA concentration in serum) and a lipid emulsion group (high FFA concentration in serum). The area under the curve of the free concentration of flurbiprofen during the alpha phase and the distribution volume of the central compartment of flurbiprofen were significantly higher in the lipid emulsion group than the control group (5.0- and 1.2-times, respectively). When FP-ax was administered at high FFA concentration, the free concentration of flurbiprofen and distribution of flurbiprofen to tissues increased transiently. This administration method may be useful for patients with cancer pain, having a potent analgesic effect.

NSAIDS or paracetamol, alone or combined with opioids, for cancer pain

BACKGROUND

NSAIDs are widely applied to treat cancer pain and are frequently combined with opioids in combination preparations for this purpose. However, it is unclear which agent is most clinically efficacious for relieving cancer-related pain, or even what may be the additional benefit of combining an NSAID with an opioid in this setting.

OBJECTIVES

To assess the effects of NSAIDs, alone or combined with opioids, for the treatment of cancer pain.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (Issue 2, 2002), MEDLINE (January 1966 to March 2003), EMBASE (January 1980 to December 2001), LILACS (January 1984 to December 2001) and reference list of articles.

SELECTION CRITERIA

Randomized controlled trials and controlled clinical trials that compared NSAID versus placebo; NSAID versus NSAID; NSAID versus NSAID plus opioid; opioid versus opioid plus NSAID; or NSAID versus opioid.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial quality and extracted data. Study authors were contacted for additional information. Adverse event information was collected from trials. Where there was disagreement between reviewers, the opinion of an additional reviewer was sought to resolve the issue.

MAIN RESULTS

Forty-two trials involving 3084 patients were included. Clinical heterogeneity of study methods and outcomes precluded meta-analyses and only supported a qualitative systematic review. Seven of eight papers that compared NSAID with placebo demonstrated superior efficacy of NSAID with no difference in side effects. Thirteen papers compared one NSAID with another; four reported increased efficacy of one NSAID over another. Four different studies found that one NSAID had fewer side effects than one or more others. Twenty-three studies compared NSAIDs and opioids in combination or alone with NSAID/opioid combinations. Thirteen out of 14 studies found no difference, or low clinical difference, when combining an NSAID plus an opioid versus either drug alone. Comparisons between various NSAID/opioid combinations were inconclusive. Nine studies assessed the association between dose and efficacy and safety. Four papers demonstrated increased efficacy with increased dose, but no dose-dependent increase in side effects within the dose ranges studied. Study duration ranged from single dose studies performed over six hours to crossover studies lasting six weeks; however the majority of studies were of less than seven days duration.

AUTHORS' CONCLUSIONS

Based upon limited data, NSAIDs appear to be more effective than placebo for cancer pain; clear evidence to support superior safety or efficacy of one NSAID over another is lacking; and trials of combinations of an NSAID with an opioid have disclosed either no difference (4 out of 14 papers), a statistically insignificant trend towards superiority (1 out of 14 papers), or at most a slight but statistically significant advantage (9 out of 14 papers), compared with either single entity. The short duration of studies undermines generalization of their findings on efficacy and safety of NSAIDs for cancer pain.

Nonsteroidal Anti-Inflammatory Drugs, Alone or Combined With Opioids, for Cancer Pain

Purpose

To assess the safety and efficacy of nonsteroidal anti-inflammatory drugs (NSAIDs), alone or combined with opioids, for the treatment of cancer pain.

Patients and Methods

Forty-two trials involving 3,084 patients met inclusion criteria: eight compared NSAID with placebo; 13 compared one NSAID with another; 23 compared NSAID with opioid, NSAID or opioid versus NSAID plus opioid combinations, or NSAID plus opioid combinations versus NSAID plus opioid combinations; and nine studies assessed the effect of increasing NSAID dose.

Results

Sixteen studies lasted 1 week or longer and 11 evaluated a single dose. Seven of eight trials demonstrated superior efficacy of single doses of NSAID compared with placebo. Only four of 13 studies reported increased efficacy of one NSAID compared with another; four other studies found that one NSAID had fewer side effects than one or more others. Thirteen of 14 studies found no difference, or minimal clinical difference, when comparing an NSAID plus opioid combination versus either drug alone. Comparisons between various NSAID plus opioid combinations were inconclusive. Four studies demonstrated increased efficacy with increased NSAID dose, without dose-dependent increases in side effects.

Conclusion

Heterogeneity of study methods and outcomes precluded meta-analyses. Short duration of studies undermines generalization of findings on efficacy and safety. On the basis of limited data, NSAIDs appear to be more effective than placebo for cancer pain; clear evidence to support superior safety or efficacy of one NSAID compared with another is lacking; and trials of combinations of an NSAID with an opioid have disclosed either no significant difference, or at most a slight but statistically significant advantage, compared with either single entity.

Drug combinations in pain treatment: a review of the published evidence and a method for finding the optimal combination

The evidence of the usefulness of drug combinations in pain management is reviewed and the problem of finding the optimal combination is presented. For post-operative pain, adding a non-steroidal anti-inflammatory drug (NSAID) or paracetamol to intravenous morphine is beneficial. Adding ketamine to intravenous morphine may be advantageous, but ketamine has a narrow therapeutic window. The combination paracetamol-NSAID is probably superior to either component alone. For post-operative epidural analgesia, combinations of low doses of a local anaesthetic, an opioid and adrenaline (epinephrine) are superior to single-drug regimens. There are virtually no data on the advantages of combinations over single drugs in neuropathic and chronic musculoskeletal pain. Adding NSAIDs or ketamine to opioids may be useful in cancer pain. Because of the enormous number of possible combinations, randomized controlled trials may fail to test the optimal combination. A stepwise optimization model that has been applied in clinical investigations is presented.

A randomised controlled study on the use of anti-inflammatory drugs in patients with cancer pain on morphine therapy: effects on dose-escalation and a pharmacoeconomic analysis

The role of non-steroidal anti-inflammatory drugs (NSAIDs) in cancer pain has been well established in the treatment of mild pain and in association with opioids in the treatment of moderate to severe pain. The aim of this study was to verify the effects of NSAIDs on morphine escalation in advanced cancer patients with pain followed-up at home and to assess the pharmacoeconomic implications. A prospective randomised controlled study was carried out in 156 consecutive advanced cancer patients with pain followed-up at home in the period December 1999-December 2000. In this group of patients, 47 were selected with pain progression after 1 week of opioid stabilisation. Patients were randomly assigned to one of two groups: group 'O' patients were treated with continuing opioid escalation according to their clinical needs; group 'OK' received ketorolac 60 mg/daily orally (p.o.) in three doses and then continued opioid escalation according to their clinical situation. Performance status, doses of morphine before and after starting treatment, mean weekly pain intensity (assessed by means of a numerical scale from 0 to 10), mean weekly symptoms intensity, adverse effects and pain mechanisms were recorded. Moreover, drug costs per day in both groups were calculated. Patients who received ketorolac in addition to morphine showed a better analgesia after a week in comparison to the group treated with morphine only (P=0.005). Thereafter, morphine escalation was slower and the maximum morphine dose was lower in the group treated with ketorolac. The incidence and the severity of gastric discomfort was more evident in patients treated with ketorolac, while constipation was significantly increased in patients who received morphine only. Drug costs per day were similar in both groups; statistical differences were observed in patients who started on lower morphine doses (<100 mg/daily) in the two groups (4.3 in the ketorolac-morphine group versus 3.4 in the morphine group; P=0.012). The use of NSAIDs reduces the need for an opioid dose escalation or allows the use of lower doses. Their use is associated with a more intense gastric discomfort, but results in less opioid-related constipation. The eventual additive cost for NSAIDs therapy is negligible, especially in patients taking high doses of morphine.

Drug interactions with patient-controlled analgesia

Patient-controlled analgesia (PCA) has become standard procedure in the clinical treatment of pain. Its widespread use in patients with all kinds of diseases opens a variety of possible interactions between analgesics used for PCA and other drugs that might be administered concomitantly to the patient. Many of these drug interactions are of little clinical importance. However, some drug interactions have been reported to result in serious clinical problems. Drug interactions can either predominantly affect the pharmacokinetics or pharmacodynamics of the drug. Most important pharmacokinetic drug interactions occur at the level of drug metabolism or protein binding. Acceleration of methadone metabolism caused by cytochrome P450 (CYP) 3A4 induction by antiretroviral drugs or rifampicin (rifampin) has caused methadone withdrawal symptoms. Lack of morphine formation from codeine as a result of CYP2D6 inhibition by quinidine results in an almost complete loss of the analgesic effects of codeine. Alterations of methadone protein binding caused by an inhibition of alpha1-acid glycoprotein synthesis by alkylating substances are another possibility for predominantly pharmacokinetically based drug interactions during PCA. Furthermore, inhibition of P-glycoprotein by anticancer drugs could result in altered transmembrane transport of morphine, methadone or fentanyl, although this has not been shown to be of clinical relevance. Synergistic effects of systemically administered opioids with spinally or topically delivered opioids or anaesthetics have been reported frequently. The same is true for the opioid-sparing effects of coadministered non-opioid analgesics. Antidepressants, anticonvulsants or alpha2-adrenoreceptor agonists have also been shown to exert additive analgesic effects when administered together with an opioid. Inconsistent findings, however, are reported regarding the treatment of patients with opioid-induced nausea and sedation, since coadministration of antiemetics either increased or decreased the respective adverse effects or revealed additional unwanted drug effects.

Diclofenac does not interact with codeine metabolism in vivo: a study in healthy volunteers

BACKGROUND

Previously, we have demonstrated a marked inhibition of codeine glucuronidation by diclofenac in human liver tissue homogenate. We therefore aimed to investigate whether diclofenac inhibits glucuronidation of codeine also in vivo in healthy volunteers.

METHODS

In a randomised, placebo-controlled, double-blind, cross-over study, 12 healthy volunteers received a singe of 100 mg codeine phosphate plus 50 mg diclofenac sodium or codeine phosphate plus placebo. Over a 36 hour period serum concentrations of codeine and its metabolites as well as urinary excretion were analysed using LC-mass spectrometry. Side effects were recorded and analgesic efficacy was determined using the cold pressor test (0-6 h).

RESULTS

A single dose of diclofenac did not alter the formation of codeine-6-glucuronide in healthy volunteers. Metabolic clearance of codeine to morphine was not affected by diclofenac. In terms of side effects, both treatments were well tolerated. Diclofenac did not significantly influence the analgesic effects of codeine in the cold pressor test.

CONCLUSIONS

In contrast to recent in vitro data, a single oral dose of diclofenac did not alter the glucuronidation of codeine in healthy volunteers.

Valdecoxib, a COX-2-specific inhibitor, is an efficacious, opioid-sparing analgesic in patients undergoing hip arthroplasty

Opioid agents are highly effective analgesics after orthopedic surgery but are associated with several adverse effects. Valdecoxib is a new, highly selective cyclooxygenase (COX)-2-specific inhibitor with a rapid onset of action and significant analgesic properties that is being developed for the management of acute pain. The objective of this study was to demonstrate the opioid-sparing efficacy of valdecoxib as part of a multimodal treatment of pain associated with hip arthroplasty. This multicenter, multiple-dose, double-blind, parallel-group study compared the opioid-sparing effects, analgesic efficacy, and safety of 20- and 40-mg doses of valdecoxib twice daily with placebo in patients receiving morphine by patient-controlled analgesia after hip arthroplasty. Study medication was first administered 1 to 3 hours preoperatively. The total amount of morphine administered, pain intensity, and patient's global evaluation of study medication were assessed over a period of 48 hours. Patients receiving 20 or 40 mg valdecoxib twice daily required on average 40% less morphine than those receiving placebo after hip arthroplasty. Pain intensity levels and patient satisfaction were significantly improved in both valdecoxib groups compared with placebo. Valdecoxib and placebo were equally well tolerated. Pre- and postoperative administration of valdecoxib reduces the amount of morphine required for postoperative pain relief and provides greater analgesic efficacy compared with morphine alone. Thus, valdecoxib has significant clinical utility for acute pain management in orthopedic surgery patients.

Strategies to manage the adverse effects of oral morphine: an evidence-based report

Successful pain management with opioids requires that adequate analgesia be achieved without excessive adverse effects. By these criteria, a substantial minority of patients treated with oral morphine (10% to 30%) do not have a successful outcome because of (1) excessive adverse effects, (2) inadequate analgesia, or (3) a combination of both excessive adverse effects along with inadequate analgesia. The management of excessive adverse effects remains a major clinical challenge. Multiple approaches have been described to address this problem. The clinical challenge of selecting the best option is enhanced by the lack of definitive, evidence-based comparative data. Indeed, this aspect of opioid therapeutics has become a focus of substantial controversy. This study presents evidence-based recommendations for clinical-practice formulated by an Expert Working Group of the European Association of Palliative Care (EAPC) Research NETWORK: These recommendations highlight the need for careful evaluation to distinguish between morphine adverse effects from comorbidity, dehydration, or drug interactions, and initial consideration of dose reduction (possibly by the addition of a co analgesic). If side effects persist, the clinician should consider options of symptomatic management of the adverse effect, opioid rotation, or switching route of systemic administration. The approaches are described and guidelines are provided to aid in selecting between therapeutic options.

The use of anti-inflammatory drugs in cancer pain

The role of non-steroidal anti-inflammatory drugs (NSAIDs) in cancer pain has been well established in the treatment of mild pain and also alone or in association with opioids for the treatment of moderate to severe pain. Acutely, NSAIDs may be more than mild analgesics, and may provide additional analgesia when combined with opioids. However, NSAIDs have ceiling effects and there is no therapeutic gain from increasing dosages beyond those recommended. As there is no clearly superior NSAID, the choice should be based on experience and the toxicity profile that probably relates to the COX-1:COX-2 ratio. Among the older drugs, ibuprofen seems to have these properties.Non-steroidal anti-inflammatory drugs have been shown to have an opioid-sparing effect. Although the value of a simple narcotic-sparing effect may be questioned in cancer pain treatment, the use of NSAIDs may be useful when the increase in opioid dosage determine the occurrence of opioid toxicity. Like opioids, NSAIDs should not be considered analgesics for a specific type or cause of pain. There is a lack of evidence for any difference between different routes of NSAIDs administration. The long-term toxicity of NSAIDs in cancer pain is poorly defined due to a lack of studies. A variety of strategies have been used in an attempt to reduce the risks associated with NSAID therapy. Those NSAIDs that are weak COX-1 inhibitors may be preferred. In addition, concomitant administration of misoprostol is recommended in patients at increased risk for upper gastrointestinal complications.

Analgesic effects of nonsteroidal anti-inflammatory drugs in cancer pain due to somatic or visceral mechanisms

The role of nonsteroidal anti-inflammatory drugs (NSAIDs) is well established in the treatment of cancer pain. This class of drugs is considered particularly effective in pain due to somatic mechanisms, although proof of this observation is lacking. To ascertain whether NSAIDs are more effective in specific nociceptive forms of cancer pain, they were administered alone or added to opioids in 32 patients with a sole pain mechanism, somatic pain due to bone metastases (17 patients) or visceral pain (15 patients), respectively. Pain intensity, mean doses of opioids used, and symptoms were recorded after starting NSAID. A significant reduction in pain intensity was found at 3, 7, and 14 days. No differences in pain intensity between the two groups were observed. However, patients with a visceral mechanism required higher opioid doses after a week of treatment. No differences in adverse effects were reported. NSAIDs may be useful drugs in the management of cancer pain, regardless of the mechanism of pain involved. The incidence of adverse effects during prolonged administration should be assessed in future studies.

Nonsteroidal anti-inflammatory drugs as adjuvant analgesics in cancer patients

The role of nonsteroidal anti-inflammatory drugs (NSAIDs) is examined in the control of cancer pain with a particular focus on their use as adjuvants to opioids in advanced cancer pain. These agents have both a peripheral effect on inflammation and a role in attenuating central pain pathways. The possibility of obtaining the benefits of NSAIDs with fewer side-effects by using COX-2-specific agents is discussed. The gastrointestinal, renal, haemostatic, cognitive and hypersensitivity side-effects of NSAIDs are reviewed and their potential impact assessed. The evidence for the efficacy of NSAIDs as single agents for cancer pain is reviewed together with the nine papers which have reported the effects of NSAIDs as adjuvants to opioids in cancer pain. All of these papers reported positive results of NSAIDs, but, in the absence of any randomized, double-blind controlled trials, where NSAIDs were used as adjuvants on a long-term basis alongside optimal opioid use, definite conclusions cannot be reached. Guidelines for the safe use of NSAIDs are suggested. Finally, suggestions for future research are made.

The opioid-sparing effects of intravenous ketorolac as an adjuvant analgesic in cancer pain: application in bone metastases and the opioid bowel syndrome

Side effects of morphine are common when given in titrated doses to control severe pain in advanced cancer. We report a case series of acutely ill cancer patients suffering from pain, complications of advanced disease, and opioid side effects. They were treated with intravenous (i.v.) ketorolac along with i.v. morphine using repeated dosing. Excellent pain relief with improvement in the opioid bowel syndrome was achieved. We found it possible to switch from IV ketorolac to oral ketorolac along with oral morphine for long-term pain control. Ketorolac can be well tolerated in high-dose, long-term use even in this frail patient population. An algorithm is presented for the suggested use of ketorolac as a morphine sparing agent. Potential methods for studying ketorolac further in this role are discussed.

Opioid-sparing effect of diclofenac in cancer pain

This study investigated the opioid-sparing effect of diclofenac using patient-controlled analgesia with oral methadone. Fifteen patients with advanced cancer participated. After achieving adequate analgesia with regular dosing of oral methadone (T1), patient-controlled analgesia with methadone was administered for 3 days (T2). Intramuscular diclofenac 75 mg twice daily was then added to this regimen for 3 days (T3). Compared to T2 values, methadone dose was significantly reduced at T2 and T2, and pain report (recorded on a visual analogue scale) was significantly reduced at T3. A reduction in methadone plasma concentration was also observed at T2 and T3, although it did not attain statistical significance. Significant decreases in the intensity of several symptoms other than pain were also found at T2 and T3. Diclofenac appears to have a relevant opioid-sparing effect when using patient-controlled analgesia with oral methadone.

Pain and Symptom Management in Palliative Care

BACKGROUND: Pain, dyspnea, and anorexia are common symptoms experienced by patients with cancer and often are poorly managed. METHODS: The incidence and causes of these symptoms are described, as well as factors that exacerbate or ameliorate their impact. RESULTS: Pharmacologic management of cancer pain is based on the use of a sequential "ladder" that incorporates nonopioid, opioid, and adjuvant drugs, depending on the severity of the pain. This approach usually is effective. Other symptoms of advanced disease may be more difficult to control. CONCLUSIONS: Adherence to an adequate pain-control strategy will significantly enhance palliation of pain in patients with cancer.

The morphine-sparing effect of propacetamol in orthopedic postoperative pain

The analgesic efficacy and safety of propacetamol (Pro-Dafalgan), an injectable prodrug of acetaminophen, in combination with morphine administered by patient-controlled analgesia (PCA) were studied in 60 patients (56 men, 4 women; age 18-40 years; mean age, 26 years) after knee ligamentoplasty. Using a double-blind, randomized, parallel-group design, the effects of four (every 6 hr) intravenous injections of 2 g propacetamol (= 1 g acetaminophen) were compared with four injections of placebo (PL) in the recovery room immediately after surgery. Efficacy was assessed over 24 hr by automatic recording on the PCA device of the cumulative dose of morphine and the number of boluses requested. It was also assessed on pain scores rated on a five-point verbal scale and a visual analogue scale before administration, at 1, 2, 3, and 4 hr, and then every 2 hr until the 24th hr after administration. A five-point global efficacy scale was also administered. Any side effects were recorded throughout the duration of the study, and the ability to tolerate the drug was assessed by recording arterial pressure, cardiac and respiratory frequency, and sedation at the same assessment times as the pain scores. The 24-hr morphine consumption was significantly decreased in the propacetamol group (number of 1 mg boluses: 14.7 +/- 11.3 versus 23.2 +/- 13.8, P = 0.01; PCA usage: 26.4 +/- 12.3 mg versus 34.6 +/- 15.4 mg, P = 0.03; PCA usage + titration: 34.5 +/- 12.7 mg versus 43.1 +/- 15.9 mg, P = 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Outcomes of epidural morphine treatment in cancer pain: nine years of clinical experience

The outcome of epidural morphine therapy is described in 146 consecutive cancer patients who were treated by a community hospital-based pain service. The routine procedure used a standard epidural catheter that was tunneled subcutaneously. One hundred and twenty-one patients improved and stayed on lifelong or chronic epidural opioids. Mean treatment time was 92 days (median, 47; range, 2-2040); 49% of the time was spent as outpatients. Twenty-five patients failed to respond to the treatment. The oral daily morphine-equivalent dose prior to inclusion was 164 mg. The mean daily epidural start dose of morphine was 18 mg (range, 6-120), and the mean daily dose at termination was 69 mg (range, 2-540). The dose escalations, described as the ratio of the maximum dose to the minimum maintenance start dose, were moderate, with a mean of 4.1 (median, 2.5), which corresponded to a percent increase of 5.1 (median, 2.7) per patient per day. Lack of effect due to the character of the original symptoms or progression of pain was the main reason for withdrawal from epidural opioid therapy (N = 27), followed by catheter-related problems (N = 9) and drug-related complications (N = 5). Also due to drug-related complications, epidural morphine therapy was changed to buprenorphine or methadone in 19 patients. Adjuvant systemic opioids were given to ten patients and epidural local anesthetics were administered to 17 of the subjects. Neuropathic pain, certain visceral pain types, incident pain on movement, and pain from cutaneous ulcerations were characteristics of poor responders.(ABSTRACT TRUNCATED AT 250 WORDS)

Pain control: some aspects of day-to-day management

A practical framework for the management of pain control in palliative care of patients with advanced malignancies, using analgesics and co-analgesics is described. The analgesic ladder is used as a model for the logical progression of options for the day-to-day application of analgesics. Strong opioids and their side-effects are discussed. Indications for the most frequently applied co-analgesics are given, including the more commonly required psychotropic agents.