Randomized double-blind, double-dummy crossover clinical trial of oral tramadol versus rectal tramadol administration in opioid-naive cancer patients with pain

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.

Transmucosal drug administration as an alternative route in palliative and end-of-life care during the COVID-19 pandemic

The Coronavirus disease 2019 (COVID-19) pandemic has led to a surge in need for alternative routes of administration of drugs for end of life and palliative care, particularly in community settings. Transmucosal routes include intranasal, buccal, sublingual and rectal. They are non-invasive routes for systemic drug delivery with the possibility of self-administration, or administration by family caregivers. In addition, their ability to offer rapid onset of action with reduced first-pass metabolism make them suitable for use in palliative and end-of-life care to provide fast relief of symptoms. This is particularly important in COVID-19, as patients can deteriorate rapidly. Despite the advantages, these routes of administration face challenges including a relatively small surface area for effective drug absorption, small volume of fluid for drug dissolution and the presence of a mucus barrier, thereby limiting the number of drugs that are suitable to be delivered through the transmucosal route. In this review, the merits, challenges and limitations of each of these transmucosal routes are discussed. The goals are to provide insights into using transmucosal drug delivery to bring about the best possible symptom management for patients at the end of life, and to inspire scientists to develop new delivery systems to provide effective symptom management for this group of patients.

Tramadol with or without paracetamol (acetaminophen) for cancer pain

BACKGROUND

Tramadol is an opioid analgesic licensed for use in moderate to severe pain. It is considered as a low risk for abuse, so control regulations are not as stringent as for 'strong' opioids such as morphine. It has a potential role as a step 2 option of the World Health Organization (WHO) analgesic ladder.

OBJECTIVES

To assess the benefits and adverse effects of tramadol with or without paracetamol (acetaminophen) for cancer-related pain.

SEARCH METHODS

We searched the following databases using a wide range of search terms: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and LILACS. We also searched three clinical trials registry databases. The date of the last search was 2 November 2016.

SELECTION CRITERIA

We selected studies that were randomised, with placebo or active controls, or both, and included a minimum of 10 participants per treatment arm. We were interested particularly in blinded studies, but also included open studies.We excluded non-randomised studies, studies of experimental pain, case reports, and clinical observations.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data using a standard form and checked for agreement before entry into Review Manager 5. We included information about the number of participants treated and demographic details, type of cancer, drug and dosing regimen, study design (placebo or active control) and methods, study duration and follow-up, analgesic outcome measures and results, withdrawals, and adverse events. We collated multiple reports of the same study, so that each study, rather than each report, was the unit of interest in the review. We assessed the evidence using GRADE and created a 'Summary of findings' table.The main outcomes of interest for benefit were pain reduction of 30% or greater and 50% or greater from baseline, participants with pain no worse than mild, and participants feeling much improved or very much improved.

MAIN RESULTS

We included 10 studies (12 reports) with 958 adult participants. All the studies enrolled participants with chronic malignant tumour-related pain who were experiencing pain intensities described as moderate to severe, with most experiencing at least 4/10 with current treatment. The mean ages were 59 to 70 years, with participants aged between 24 and 87 years. Study length ranged from one day to six months. Five studies used a cross-over design. Tramadol doses ranged from 50 mg as single dose to 600 mg per day; doses of 300 mg per day to 400 mg per day were most common.Nine studies were at high risk of bias for one to four criteria (only one high risk of bias for size). We judged all the results to be very low quality evidence because of widespread lack of blinding of outcome assessment, inadequately described sequence generation, allocation concealment, and small numbers of participants and events. Important outcomes were poorly reported. There were eight different active comparators and one comparison with placebo. There was little information available for any comparison and no firm conclusions could be drawn for any outcome.Single comparisons of oral tramadol with codeine plus paracetamol, of dihydrocodeine, and of rectal versus oral tramadol provided no data for key outcomes. One study used tramadol combined with paracetamol; four participants received this intervention. One study compared tramadol with flupirtine - a drug that is no longer available. One study compared tramadol with placebo and a combination of cobrotoxin, tramadol, and ibuprofen, but the dosing schedule poorly explained.Two studies (191 participants) compared tramadol with buprenorphine. One study (131 participants) reported a similar proportion of no or mild pain at 14 days.Three studies (300 participants) compared tramadol with morphine. Only one study, combining tramadol, tramadol plus paracetamol, and paracetamol plus codeine as a single weak-opioid group reported results. Weak opioid produced reduction in pain of at least 30% from baseline in 55/117 (47%) participants, compared with 91/110 (82%) participants with morphine. Weak opioid produced reduction in pain of at least 50% in 49/117 (42%) participants, compared with 83/110 (75%) participants with morphine.There was no useful information for any other outcome of benefit or harm.

AUTHORS' CONCLUSIONS

There is limited, very low quality, evidence from randomised controlled trials that tramadol produced pain relief in some adults with pain due to cancer and no evidence at all for children. There is very low quality evidence that it is not as effective as morphine. This review does not provide a reliable indication of the likely effect. The likelihood that the effect will be substantially different is very high. The place of tramadol in managing cancer pain and its role as step 2 of the WHO analgesic ladder is unclear.

Physicochemical properties, in vitro release and in vivo evaluation of tramadol hydrochloride rectal suppository and rectal gel

Background: Tramadol is a centrally acting analgesic drug. Rectal administration of tramadol is useful in the treatment of post-operative pain or malignant pain in cases where it cannot be administered orally. In Thailand, tramadol is available only as a capsule for oral use and as a solution for injection.

Objective: Develop tramadol hydrochloride rectal suppositories and rectal gel preparations.

Methods: Tramadol rectal suppository and rectal gel were prepared. Physicochemical properties (viscosity, gel strength, mucoadhesive force) and the in vitro release of tramadol hydrochloride were investigated from different bases (Witepsol H15, polyethylene glycol, poloxamer, and hydroxyethylcellulose). The analgesic activity of rectal tramadol hydrochloride using the hot plate test was evaluated in rats.

Results: Tramadol hydrochloride rectal gel using poloxamer was more mucoadhesive to the rectal mucous membrane than was the gel with the hydroxyethylcellulose base. Tramadol hydrochloride was released rapidly in vitro from both the Witepsol H15 and polyethylene glycol bases. It was completely released from the polyethylene glycol suppository base within 15 minutes. The amount of tramadol hydrochloride release from the Witepsol H15 suppository base was about 93% at 120 minutes. When using poloxamer or hydroxyethylcellulose as a rectal base, tramadol hydrochloride was released from both bases rapidly and completely released within 15 minutes. Administration of a tramadol hydrochloride suppository in rats exhibited a more pronounced analgesic effect with the polyethylene glycol base than with the Witepsol H15-based suppositories. The rectal gel had a less pronounced analgesic effect when made with the hydroxyethylcellulose base than with the poloxamer base.

Conclusion: Tramadol hydrochloride suppositories and rectal gels with different bases showed rapid and almost complete drug release from the bases, prolonging the latency of a nociceptive response in in vivo experiments.

How are palliative care cancer populations characterized in randomized controlled trials? A literature review

CONTEXT

The difficulties in defining a palliative care patient accentuate the need to provide stringent descriptions of the patient population in palliative care research.

OBJECTIVES

To conduct a systematic literature review with the aim of identifying which key variables have been used to describe adult palliative care cancer populations in randomized controlled trials (RCTs).

METHODS

The data sources used were MEDLINE (1950 to January 25, 2010) and Embase (1980 to January 25, 2010), limited to RCTs in adult cancer patients with incurable disease. Forty-three variables were systematically extracted from the eligible articles.

RESULTS

The review includes 336 articles reporting RCTs in palliative care cancer patients. Age (98%), gender (90%), cancer diagnosis (89%), performance status (45%), and survival (45%) were the most frequently reported variables. A large number of other variables were much less frequently reported.

CONCLUSION

A substantial variation exists in how palliative care cancer populations are described in RCTs. Few variables are consistently registered and reported. There is a clear need to standardize the reporting. The results from this work will serve as the basis for an international Delphi process with the aim of reaching consensus on a minimum set of descriptors to characterize a palliative care cancer population.

The second step of the analgesic ladder and oral tramadol in the treatment of mild to moderate cancer pain: a systematic review

BACKGROUND

To analyse the evidence supporting the widespread use of modified analgesic ladders or oral tramadol as alternatives to codeine/paracetamol for mild to moderate cancer pain.

METHODS

A systematic review of the literature was independently performed by two authors. The level of evidence and risk/benefit ratio were assessed in all the selected trials. A comprehensive analysis of the level of evidence, risk/benefit ratio and strength of the recommendations was carried out. The analysis was performed using the GRADE system.

RESULTS

Eighteen papers were included into the analysis. The level of evidence was low or very low for all the trials, and as a result the risk/benefit ratio was uncertain. Likewise, the strength of the final recommendations was considered weak negative for either the use of modified analgesic ladders (by-passing the second step of the World Health Organization (WHO) analgesic ladder) or the use of oral tramadol as an alternative to codeine/paracetamol in the second step of the WHO analgesic ladder.

CONCLUSIONS

Data supporting the role of modified two-step analgesic ladders or oral tramadol as an alternative to codeine/paracetamol are insufficient to recommend their routine use in cancer patients with mild to moderate cancer pain.

Slow release tramadol in the initial treatment of moderate to severe cancer pain: Open, multicentric clinical trial

Introduction The analgesic efficacy of slow release tramadol in the titration phase of treatment of moderate to severe cancer pain has been demonstrated in clinical trials. Objective The aim of the study was to evaluate this treatment strategy in routine daily practice. Method This was a prospective, non-randomized, open, multicentric, phase IV two-week study. Each patient received 100 mg slow release tramadol orally, twice a day. Patients were allowed to take 20 drops (50 mg) of tramadol as needed for breakthrough pain. The pain intensity and tramadol tolerability were recorded every day for the previous 24 hours, in the first week and at the end of the study. Pain relief and the impact of pain on sleep were evaluated on the 8th and 15th day. Results The study included 46 patients with metastatic malignant disease. The total of 46 patients completed the first week of treatment, and 33 patients completed the whole study. At the end of study, the intensity of pain was significantly reduced from 6.75 to 3.03 on numerical scale (NS 0-10) (p<0.001). At the end of study, 60.6% of patients graded the severity of pain as maximally mild on a verbal scale. The pain relief significantly improved from 25.75 to 71.81 on a numerical scale (NS 0-100) (p<0.001). The impact of pain on sleep was significantly reduced from 51.51% to 10.61% on a numerical scale (NS 0-100) (p<0.001). There were no differences in the drowsiness/confusion, nausea, vomiting, dizziness, loss of appetite and constipation, from the beginning to the end of treatment. Conclusion Tramadol slow release was effective in the titration phase of treatment of moderate to severe cancer pain with good tolerability.

Opioids in pain management of blood-related malignancies

Opioids are basic analgesics used in the treatment of moderate to severe pain in patients affected by blood-related malignancies. They should be sequentially administered according to the World Health Organisation scale for cancer pain. Initial treatment and titration with opioids should be based on immediate-release preparations, to be administered at appropriate intervals in order to relieve pain and to satisfy the individual opioid requirement. Once a relatively good pain control has been achieved, a slow release formulation at equivalent doses can be given. Most patients can be adequately managed using oral formulation opioids. However, a small group, such as those presenting severe mucositis or requiring a rapid pain relief, should be managed by intravenous continuous infusion and/or by a patient-controlled analgesia system; while for patients in the community, there are distinct advantages to using the subcutaneous route. Other available routes of administration for opioids, can be used in selected circumstances, including rectal, transdermal, epidural, intrathecal and intramuscular. The invasive neuraxial route has a very limited role in patients with haematological malignancies, given the high risk of infection and bleeding. Through a close observation and a careful management, opioid-related side effects can be effectively prevented and treated. This article reviews the principles of opioid therapy and how opioids can be adapted for patients with pain due to haematological malignancies.