Nonsteroidal anti-inflammatory drugs as adjuvant analgesics in cancer patients

Use of non-opioid analgesics as adjuvants to opioid analgesia for cancer pain management in an inpatient palliative unit: does this improve pain control and reduce opioid requirements?

BACKGROUND

Cancer pain is complex, and despite the introduction of the WHO cancer pain ladder, few studies have looked at the prevalence of adjuvant medication use in an inpatient palliative medicine unit. In this study, we evaluate the use of adjuvant pain medications in patients admitted to an inpatient palliative care unit and whether their use affects pain scores or opiate dosing.

METHODS

In this retrospective observational study, patients admitted to the inpatient palliative care unit over a 3-month period with a diagnosis of cancer on opioid therapy were selected. Data pertaining to demographics, diagnosis, oral morphine dose equivalent of the opioid at the time of discharge, adjuvant analgesics, nonsteroidal anti-inflammatory drugs (NSAIDs), and pain scores as reported by nurses and physicians were collected.

RESULTS

Seventy-seven patients were eligible over a 3-month period, out of which 65 (84 %) were taking an adjuvant medication. The most commonly prescribed adjuvant was gabapentin (70 %). Fifty-seven percent were taking more than one adjuvant. There were more women in the group receiving adjuvants (57 vs. 17%, p = 0.010). Those without adjuvants compared with those on adjuvants did not have worse pain scores on discharge as reported by physicians (0.8 ± 0.8 vs. 1.0 ± 0.7, p = 0.58) or nurses (2.0 ± 2.7 vs. 2.1 ± 2.6, p = 0.86). There was no difference in morphine equivalent doses of the opioid in both groups (median (min, max); 112 (58, 504) vs. 200 (30, 5,040)) at the time of discharge; 75-80 % of patients had improvement in pain scores as measured by a two-point reduction in numerical rating scale (NRS).

DISCUSSION

This study shows that adjuvant medications are commonly used for treating pain in patients with cancer. More than half of study population were on two adjuvants or an adjuvant plus NSAID along with an opioid. We did not demonstrate any benefit in terms of improved pain scores or opioid doses with adjuvants, but this could reflect confounding variables and physician choice. Larger prospective studies are needed to define the opioid-sparing effects of adjuvants.

CONCLUSION

Adjuvant agents are used in over 80 % of those treated for cancer pain.

Adjuvant analgesics in cancer pain: a review

Adjuvant analgesics (co-analgesics) are medications whose primary indication is the management of a medical condition with secondary effects of analgesia. Cancer pain is multifactorial and often involves inflammatory, nociceptive, and neuropathic pain subtypes. Adjuvant analgesics used in conjunction with opioids have been found to be beneficial in the management of many cancer pain syndromes; however, they are currently underutilized. Antidepressants, anticonvulsants, local anesthetics, topical agents, steroids, bisphosphonates, and calcitonin are all adjuvants which have been shown to be effective in the management of cancer pain syndromes. When utilizing analgesic adjuvants in the treatment of cancer pain, providers must take into account the particular side effect profile of the medication. Ideally, adjuvant analgesics will be initiated at lower dosages and escalated as tolerated until efficacy or adverse effects are encountered.

Prospective audit of short-term concurrent ketamine, opioid and anti-inflammatory (‘triple-agent’) therapy for episodes of acute on chronic pain

AIM

This prospective audit was undertaken in order to document the analgesic response and adverse effects of concurrent short-term ('burst') triple-agent analgesic (ketamine, an opioid and an anti-inflammatory agent--either steroidal or non-steroidal) administration, for episodes of acute on chronic pain. The clinical hypothesis in this study is that better pain control may be obtained by simultaneous multiple target receptor blockade.

METHOD

The response of 18 patients is reported. The pain and analgesic requirement data for the 24 h before starting triple-agent therapy were compared with the last 24 h on the triple-agent therapy. Patients were then classified as responders or non-responders.

RESULTS

According to stringent clinical criteria, 12 out of the 18 patients were classified as responders. The response rate was highest for somatic pain (7/9) and appeared to decrease with duration of prior uncontrolled pain. Only four out of the 18 patients reported adverse effects and all of these were minor.

CONCLUSIONS

The results suggest that this 'burst' triple-agent approach is safe and effective in an inpatient palliative care population during episodes of poorly controlled acute on chronic pain, and warrants further investigation to ascertain whether it gives superior results compared to the 'gold-standard' WHO ladder approach.

Attenuation of mechanical allodynia by clinically utilized drugs in a rat chemotherapy-induced neuropathic pain model

Chemotherapy-induced peripheral neuropathy is a common, dose-limiting side effect of cancer chemotherapeutic agents, including the vinca alkaloids such as vincristine. The resulting symptoms, which frequently include moderate to severe pain, can often be disabling. The current study utilized a vincristine-induced neuropathic pain animal model [Pain 93 (2001) 69], in which rats were surgically implanted with mini-osmotic pumps set to deliver vincristine sulfate (30 microg kg(-1)day(-1), i.v.), to examine the time course of progression of various pain modalities and to compare the dose-response effects of clinically utilized drugs on mechanical allodynia to further validate the relevance of this model to clinical pathology. Vincristine infusion resulted in significant cold allodynia after 1 week post-infusion, however mechanical and thermal nociception showed little to no effect. In contrast, marked mechanical allodynia occurred by 1 week of vincristine infusion and returned nearly to pre-infusion levels by the 4th week after infusion pump implantation. ED(50) values (micromol/kg, p.o.) were determined in the mechanical allodynia assay for lamotrigine (82), dextromethorphan (94), gabapentin (400), acetaminophen (1100) and carbamazepine (3600); however, aspirin and ibuprofen had no effects up to 300 and 1000 micromol/kg, respectively. Additionally, ED(50) values (micromol/kg, i.p.) were determined in the mechanical allodynia assay for clonidine (0.35) and morphine (0.62), but desipramine and celecoxib had no effects up to 66 and 260 micromol/kg, respectively. Findings from the current, preclinical study further validate this model as clinically relevant for chemotherapy-induced pain. The surprisingly good effects observed with acetaminophen warrant further investigation of its mechanism(s) of action in neuropathic pain.

NSAIDs: gastroprotection or selective COX-2 inhibitor?

Conventional nonsteroidal anti-inflammatory drugs (NSAIDs) are effective adjuvant analgesics commonly encountered in palliative care. However, these drugs are associated with adverse effects that are primarily due to gastrointestinal toxicity, with resultant serious complications such as gastroduodenal perforations, ulcers and bleeds. This toxicity has been attributed to inhibition of cyclooxygenase-1 (COX-1). Factors known to increase this risk of toxicity include age above 65 years, classification of NSAID in terms of COX-1/COX-2 selectivity, previous history of complications and coadministration of aspirin, anticoagulants and corticosteroids. Selective inhibitors of cyclooxygenase-2 (COX-2) were developed in an attempt to reduce this association; trials to date confirm that these drugs do indeed have reduced incidence of gastroduodenal toxicity. Prior to the introduction of the COX-2 selective inhibitors, patients at high risk were often coprescribed a gastroprotective agent (such as misoprostol or a proton pump inhibitor) with a conventional NSAID. This review discusses the merits of both options and devises a treatment strategy for the safe and cost-effective use of these drugs in the palliative care population.

Double-blind evaluation of short-term analgesic efficacy of orally administered dexketoprofen trometamol and ketorolac in bone cancer pain

The analgesic efficacy and safety of dexketoprofen trometamol (the active enantiomer of the racemic compound ketoprofen) (25mg q.i.d.) vs. ketorolac (10mg q.i.d.) was assessed in 115 patients with bone cancer pain included in a multicenter, randomized, double-blind, parallel group study. A level of >/=40 mm on the 100 mm visual analog scale (VAS) and >/=10 in the pain rating index were required for inclusion. At the end of treatment on day 7 (+1 day), mean values of VAS were 32+/-24 mm for dexketoprofen and 40+/-30 mm for ketorolac (P=0.12) but the pain rating index was significantly lower in patients given dexketoprofen (8.5+/-2.3 vs. 9.7+/-2.9, P=0.04). Moreover, most of the patients reached a pain intensity difference from baseline >/=20 mm (75% of patients for dexketoprofen and 65% of patients for ketorolac). Around half of patients in both treatments had a pain intensity <30 mm on VAS at the end of treatment (55% for dexketoprofen and 47% for ketorolac). In the overall assessment of efficacy, a higher percentage of both patients and physicians rated dexketoprofen as 'quite effective' or 'very effective' compared to ketorolac. The percentage of patients withdrawn from the study for any reason as well as for insufficient therapeutic effect or due to adverse events was lower in the dexketoprofen group than in the ketorolac group. Treatment-related adverse events occurred in 16% of patients given dexketoprofen and in 24% given ketorolac. Serious adverse events occurred in 3.5% of patients from both groups but only one case of gastrointestinal hemorrhage was considered related to ketorolac. We conclude that dexketoprofen trometamol 25 mg q.i.d. oral route is a good analgesic therapy in the treatment of bone cancer pain, comparable to ketorolac 10 mg q.i.d., with a good tolerability profile.

Palliative care in a national cancer center: results in 1987 vs. 1993 vs. 2000

In the last few years, palliative care for advanced and terminal cancer patients has undergone considerable evolution. We determined the characteristics of patients admitted to the 4-bed Palliative Care Unit (PCU) of the National Cancer Institute (NCI) of Milan in 1987, 1993 and 2000 to evaluate how our diagnostic and therapeutic approaches have changed over the years. We reviewed the charts of every patient admitted to the PCU in 1987, 1993, and the first ten months of 2000. We recorded demographic data; the primary tumor sites; the main reason for admission; the types of therapies administered (oncologic, analgesic, surgical, neurosurgical analgesic procedures, and supportive therapy); the type and number of cardiological, radiological and endoscopic examinations, as well as specialist consultations; the duration of stay and eventual death on the Unit. There were no significant differences regarding gender, age, primary tumor site and death in hospital of the patients admitted during these years. The time spent in hospital increased over time (P = 0.006). A significant increase was observed in the percentage of patients admitted for supportive therapy (P < 0.001) and investigation concerning the stage of the disease (P < 0.001). There was a significant decrease in admission for invasive analgesic procedures (P < 0.001), as well as for pain diagnosis and/or uncontrolled pain. Uncontrolled pain remained the most frequent reason for admission. Over the years, during hospitalization, 7% to 12% of the patients underwent radiotherapy,1% to 9% had computerized tomography, and 4% to 8% had palliative surgery. More than 50% of the patients received intravenous hydration; a few patients received hypodermoclysis in 1987. Over time, there was a significant increase in "as needed" administration of nonsteroidal anti-inflammatory drugs and a significant reduction in their regular administration (from 24% in 1987 and 1993 to 3% in 2000) (P < 0.001). The use of codeine, tramadol and methadone increased (P < 0.001), whereas the use of oral morphine, buprenorphine and oxycodone decreased in 2000 (P < 0.001). There was a reduction in the use of antidepressants (no significant constant trend) and a significant increase in the use of anticonvulsants, laxatives and pamidronate (P < 0.001). Regularly administered hypnotics decreased in 1993 and increased in 2000 (P < 0.001). Over these years, no significant differences were found in the routes of opioid administration, in route switching and in the mean maximum oral opioid dose (ranging from 108 to 126 mg/day). The percentage of patients undergoing percutaneous cordotomy significantly decreased in 1993 and 2000 (P < 0.001). Over time, there was an increase in requests for specialist consultations, which was significant for neurological, cardiological and oncological consults (P < 0.001). Although the characteristics of the patients admitted to the PCU did not change over these years, there have been significant modifications in our therapeutic approaches, above all in the use of supportive therapy, adjuvant drugs, opioids and neurosurgical invasive procedures. Moreover, a major collaborative interaction with other specialists of the NCI took place with the aim to tailor treatment for each single patient.

Strategies in pain management: new and potential indications for COX-2 specific inhibitors

The role of the coxibs in the management of osteoarthritis and rheumatoid arthritis has been widely discussed, but there are other potential applications for the coxibs that have received less attention. Here we consider the use of the coxibs in acute pain syndromes such as primary dysmenorrhea and the pain associated with dental extraction, as well as considering their application in chronic low back pain and cancer pain. Another area where the coxibs may prove particularly beneficial is in the management of post-surgical pain. Traditional post-surgical analgesia has involved the use of non-selective NSAIDs and opioids, but these agents can be associated with side effects such as post-operative bleeding, gastrointestinal problems, nausea, and constipation. Because the coxibs do not inhibit COX-1 dependent platelet aggregation like traditional NSAIDs, the risk of post-surgical bleeding is reduced. The careful application of coxibs as part of a multi-modal approach to pain management in the perioperative period can reduce the requirement for opioid medications and thus reduce the risk of post-operative complications such as ileus. In the future, coxibs are likely to play an important role in multi-modal perioperative analgesic regimens with the aim of reducing post-operative periods of convalescence.

Pain management and beyond: evolving concepts and treatments involving cyclooxygenase inhibition

Chronic uncontrolled pain may be the greatest health care crisis facing the United States. It is the major symptom for which patients seek medical care and is associated with substantial economic and psychosocial costs. For many patients, particularly the elderly and those suffering from cancer, chronic pain is often undertreated. Because pain has an emotional component and is frequently accompanied by depression and/or anxiety, patients benefit from a comprehensive assessment and multidisciplinary approach to treatment. It is likely that coxibs (cyclooxygenase or COX-2-selective inhibitors) will assume an increasingly prominent role in the treatment of chronic pain associated with arthritis, cancer, and other diseases either as monotherapy or in combination with other drugs. In addition, the role of COX-2 inhibition in the prevention and treatment of colon cancer, Alzheimer's disease (AD), and other chronic health problems is an area currently undergoing intense investigation.

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.

Recent advances in pharmacotherapy for cancer pain management

PURPOSE

This review provides an outline of several recent advances in drug treatment options and strategies for managing cancer pain.

OVERVIEW

The development of cyclooxygenase-2-selective nonsteroidal anti-inflammatory drugs (NSAIDs) and transmucosal fentanyl citrate provide new pharmacologic options for the treatment of cancer pain. Combinations of opioid agonists and antagonists have provided data on new strategies to balance effective analgesia with analgesic-related adverse effects. In addition, the spectrum of adjuvant agents for the treatment of neuropathic pain has been extended to various antidepressants and topical analgesics. There is continued research on the role of the N-methyl-d-aspartate (NMDA) receptor and, specifically, on NMDA receptor antagonists that may augment analgesia and combat opioid resistance. Finally, a more potent generation of bisphosphonates may lead to improved pain relief for patients with bone metastases.

CLINICAL IMPLICATIONS

With a combination of emerging new clinical research and professional practice experience of the cancer care team, new strategies will continue to be developed and implemented, resulting in the continued improved care of patients with cancer.

Malignant bone pain: pathophysiology and treatments

Metastatic involvement of the bone is one of the most frequent causes of pain in cancer patients and represents one of the first signs of widespread neoplastic disease. The pain may originate directly from the bone, from nerve root compression, or from muscle spasms in the area of the lesions. The mechanism of metastatic bone pain is mainly somatic (nociceptive), even though, in some cases, neuropathic and visceral stimulations may overlap. The conventional symptomatic treatment of metastatic bone pain requires the use of multidisciplinary therapies, such as radiotherapy, in association with systemic treatment (hormonotherapy, chemotherapy, radioisotopes) with the support of analgesic therapy. Recently, studies have indicated the use of bisphosphonates in the treatment of pain and in the prevention of skeletal complications in patients with metastatic bone disease. In some patients, pharmacologic treatment, radiotherapy, and radioisotopes administered alone or in association are not able to manage pain adequately. The role of neuroinvasive techniques in treating metastatic bone pain is debated. The clinical conditions of the patient, his life expectancy, and quality of life must guide the physician in the choice of the best possible therapy.

Advances in cancer pain management

Control of malignant pain and related symptoms is paramount to clinical success in caring for cancer patients. To achieve the best quality of life for patients and families, oncologists and palliative care clinicians must work together to understand problems related to psychologic, social, and spiritual pain. Pain is the primary problem targeted for control using the World Health Organization's (WHO) analgesic ladder. This article focuses on increased knowledge of analgesic action that may enable expansion of the WHO analgesic ladder to fulfill the broader objectives of palliative medicine. We discuss clinical experience with several classes of drugs that are currently used to treat cancer pain: 1) nonsteroidal anti-inflammatory drugs, with emphasis on cyclooxygenase-2 inhibitors; 2) opioid analgesics, with specific emphasis on methadone and its newly recognized value in cancer pain; 3) ketamine, an antagonist at N-methyl-d-aspartate receptors; and 4) bisphosphonates, used for pain resulting from bone metastases. New concepts that compare molecular actions of morphine at excitatory opioid receptors, and methadone at nonopioid receptor systems, are presented to underscore the importance of balancing central nervous system excitatory (anti-analgesic) versus inhibitory (analgesic) influences.

Assessment and management of pain in palliative care patients

BACKGROUND

Pain affects more than 70% of cancer patients but is often undertreated.

METHODS

The authors review and present methodologies to maximize proper palliative approaches to this symptom for the majority of patients.

RESULTS

The World Health Organization's stepwise guide to pain control serves as an excellent basis for management. Around-the-clock dosing, using adjuvant treatments, and using noninvasive routes of administration provide good pain control for 80% of patients.

CONCLUSIONS

Barriers to effective pain control will be reduced as new JCAHO standards regarding pain control are implemented.

Advances in cancer pain management

Control of malignant pain and related symptoms is paramount to clinical success in caring for cancer patients. To achieve the best quality of life for patients and families, oncologists and palliative care clinicians must work together to understand problems related to psychologic, social, and spiritual pain. Pain is the primary problem targeted for control using the World Health Organization's (WHO) analgesic ladder. This article focuses on increased knowledge of analgesic action that may enable expansion of the WHO analgesic ladder to fulfill the broader objectives of palliative medicine. We discuss clinical experience with several classes of drugs that are currently used to treat cancer pain: 1) nonsteroidal anti-inflammatory drugs (NSAIDs), with emphasis on cyclooxygenase-2 (COX-2) inhibitors; 2) opioid analgesics, with specific emphasis on methadone and its newly recognized value in cancer pain; 3) ketamine, an antagonist at N-methyl d-aspartate (NMDA) receptors; and 4) bisphosphonates, used for pain resulting from bone metastases. New concepts that compare molecular actions of morphine at excitatory opioid receptors, and methadone at non-opioid receptor systems, are presented to underscore the importance of balancing central nervous system excitatory (anti-analgesic) versus inhibitory (analgesic) influences.