[Pharmacological pain management in cancer patients]

Pharmacological pain therapy in cancer patients is based on guideline recommendations, which, however, do not fully coincide in all aspects due to varying weighting of evidence. The present article discusses current issues including the decreasing significance of the World Health Organization (WHO) analgesic ladder, with its distinction between step 2 and 3 being increasingly questioned. Risks of nonopioid analgesics such as paracetamol and nonsteroidal anti-inflammatory drugs (NSAIDs), particularly in older populations, are discussed. Paracetamol may potentially reduce the effectiveness of immunotherapies. Aspects of administering analgesics via a feeding tube are considered. Recommendations for the treatment of episodic pain, transitioning between different opioids, and some relevant interactions are also discussed.

Scheduled and Breakthrough Opioid Use for Cancer Pain in an Inpatient Setting at a Tertiary Cancer Hospital

Background: Our aim was to examine the frequency and prescription pattern of breakthrough (BTO) and scheduled (SCH) opioids and their ratio (BTO/SCH ratio) of use, prior to and after referral to an inpatient supportive care consult (SCC) for cancer pain management (CPM). Methods and Materials: Patients admitted at the MD Anderson Cancer Center and referred to a SCC were retrospectively reviewed. Cancer patients receiving SCH and BTO opioids for ≥24 h were eligible for inclusion. Patient demographics and clinical characteristics, including the type and route of SCH and BTO opioids, daily opioid doses (MEDDs) of SCH and BTO, and BTO/SCH ratios were reviewed in patients seen prior to a SCC (pre-SCC) and during a SCC. A normal BTO ratio was defined as 0.5-0.2. Results: A total of 665/728 (91%) patients were evaluable. Median pain scores (p < 0.001), BTO MEDDs (p < 0.001), scheduled opioid MEDDs (p < 0.0001), and total MEDDs (p < 0.0001) were higher, but the median number of BTO doses was fewer (2 vs. 4, p < 0.001), among patients seen at SCC compared to pre-SCC. A BTO/SCH ratio over the recommended ratio (>0.2) was seen in 37.5% of patients. The BTO/SCH ratios in the pre-SCC and SCC groups were 0.10 (0.04, 0.21) and 0.17 (0.10, 0.30), respectively, p < 0.001. Hydromorphone and Morphine were the most common BTO and SCH opioids prescribed, respectively. Patients in the early supportive care group had higher pain scores and MEDDs. Conclusions: BTO/SCH ratios are frequently prescribed higher than the recommended dose. Daily pain scores, BTO MEDDs, scheduled opioid MEDDs, and total MEDDs were higher among the SCC group than the pre-SCC group, but the number of BTO doses/day was lower.

An overview of the current drug treatment strategies for moderate to severe, chronic malignant tumor-related pain

INTRODUCTION

The pharmacological management of cancer pain is a complex issue that requires knowledge and experience in the use of analgesics. The aim of this expert review is to provide a panorama of the pharmacological strategies in cancer pain management.

AREAS COVERED

Opioid dose titration is a delicate process regarding the start of opioid treatment in different clinical conditions. How to improve the opioid response is a fundamental step, which includes different strategies when an initial treatment with opioids fails. The use of adjuvants is another relevant issue that should be considered in some specific circumstances to optimize the management of cancer pain management. Some clinical conditions, such as neuropathic pain and breakthrough pain, deserve a special attention. Relevant literature was selected to provide an overview of cancer pain management strategies.

EXPERT OPINION

Opioid therapy still remains the cornerstone of pharmacological management of cancer pain. Opioids should be used according to the level of tolerance, also personalizing the treatment (route, drug, and dosing). Adjuvant drugs may help in specific conditions, although their use should be balanced with the adverse effects. Breakthrough pain requires expertise in tailoring a treatment according to patient's profile and characteristics of episodes.

Once again... breakthrough cancer pain: an updated overview

Breakthrough cancer pain (BTcP) is a complex and variegate phenomenon that may change its presentation during the course of patients' disease in the same individual. An appropriate assessment is fundamental for depicting the pattern of BTcP. This information is determinant for a personalized management of BTcP. The use of opioids as needed is recommended for the management of BTcP. There are several options which should be chosen according to the individual pattern of BTcP. In general, a drug with a short onset and offset should be preferred. Although oral opioids may still have specific indications, fentanyl products have been found to be more rapid and effective. The most controversial point regards the opioid dose to be used. The presence of opioid tolerance suggests to use a dose proportional to the dose used for background analgesia. In contrast, regulatory studies have suggested to use the minimal available dose to be titrated until the effective dose. Further large studies should definitely settle this never ended question.

Use of Opioids for Adults With Pain From Cancer or Cancer Treatment: ASCO Guideline

PURPOSE

To provide guidance on the use of opioids to manage pain from cancer or cancer treatment in adults.

METHODS

A systematic review of the literature identified systematic reviews and randomized controlled trials of the efficacy and safety of opioid analgesics in people with cancer, approaches to opioid initiation and titration, and the prevention and management of opioid adverse events. PubMed and the Cochrane Library were searched from January 1, 2010, to February 17, 2022. American Society of Clinical Oncology convened an Expert Panel to review the evidence and formulate recommendations.

RESULTS

The evidence base consisted of 31 systematic reviews and 16 randomized controlled trials. Opioids have primarily been evaluated in patients with moderate-to-severe cancer pain, and they effectively reduce pain in this population, with well-characterized adverse effects. Evidence was limited for several of the questions of interest, and the Expert Panel relied on consensus for these recommendations or noted that no recommendation could be made at this time.

RECOMMENDATIONS

Opioids should be offered to patients with moderate-to-severe pain related to cancer or active cancer treatment unless contraindicated. Opioids should be initiated PRN (as needed) at the lowest possible dose to achieve acceptable analgesia and patient goals, with early assessment and frequent titration. For patients with a substance use disorder, clinicians should collaborate with a palliative care, pain, and/or substance use disorder specialist to determine the optimal approach to pain management. Opioid adverse effects should be monitored, and strategies are provided for prevention and management.Additional information is available at www.asco.org/supportive-care-guidelines.

Cancer Pain Treatment Strategies in Patients with Cancer

Management of cancer pain is challenging. Despite the poor evidence, opioid therapy still remains the cornerstone for the management of cancer-related pain. Opioids should be given according to the clinical presentation in the different stages of disease. There is no drug of choice, as most opioids are effective. Thus, the choice should be based on the individual characteristics of patients. Optimization of opioid therapy may allow individual treatment according to the patient's characteristics and pain syndromes, providing timely alternatives in the different stages of disease. While most patients respond to an appropriate treatment associated with a comprehensive assessment and symptom control, a high level of experience and knowledge is necessary in determining conditions to maximize the analgesic response, eventually adding adjuvants in some specific circumstances. Alternative opioids may improve the balance between analgesia and adverse effects in the presence of a poor response to the first opioid in a large number of patients. Finally, a selected population can benefit from some interventional procedures.

Digital Analgesic Comprising a Second-Generation Digital Health System: Increasing Effectiveness by Optimizing the Dosing and Minimizing Side Effects

Opioids remain an essential part of the treatment of chronic pain. However, their use and increasing rates of misuse are associated with high morbidity and mortality. The development of tolerance to opioids and analgesics further complicates dosing and the need to reduce side effects. First-generation digital systems were developed to improve analgesics but are not always capable of making clinically relevant associations and do not necessarily lead to better clinical efficacy. A lack of improved clinical outcomes makes these systems less applicable for adoption by clinicians and patients. There is a need to enhance the therapeutic regimens of opioids. In the present paper, we present the use of a digital analgesic that consists of an analgesic administered under the control of a second-generation artificial intelligence system. Second-generation systems focus on improved patient outcomes measured based on clinical response and reduced side effects in a single subject. The algorithm regulates the administration of analgesics in a personalized manner. The digital analgesic provides advantages for both users and providers. The system enables dose optimization, improving effectiveness, and minimizing side effects while increasing adherence to beneficial therapeutic regimens. The algorithm improves the clinicians’ experience and assists them in managing chronic pain. The system reduces the financial burden on healthcare providers by lowering opioid-related morbidity and provides a market disruptor for pharma companies.

Modulating β-arrestin 2 recruitment at the δ- and μ-opioid receptors using peptidomimetic ligands

μ-Opioid receptor agonists provide potent and effective acute analgesia; however, their therapeutic window narrows considerably upon repeated administration, such as required for treating chronic pain. In contrast, bifunctional μ/δ opioid agonists, such as the endogenous enkephalins, have potential for treating both acute and chronic pain. However, enkephalins recruit β-arrestins, which correlate with certain adverse effects at μ- and δ-opioid receptors. Herein, we identify the C-terminus of Tyr-ψ[(Z)CF[double bond, length as m-dash]CH]-Gly-Leu-enkephalin, a stable enkephalin derivative, as a key site to regulate bias of both δ- and μ-opioid receptors. Using in vitro assays, substitution of the Leu⁵ carboxylate with amides (NHEt, NMe₂, N^CyPr) reduced β-arrestin recruitment efficacy through both the δ-opioid and μ-opioid, while retaining affinity and cAMP potency. For this series, computational studies suggest key ligand-receptor interactions that might influence bias. These findings should enable the discovery of a range of tool compounds with previously unexplored biased μ/δ opioid agonist pharmacological profiles.

The Prevalence and Characteristics of Breakthrough Cancer Pain in Patients Receiving Low Doses of Opioids for Background Pain

Simple Summary

The aim of this study was to assess the prevalence and characteristics of breakthrough cancer pain (BTcP) in patients receiving low doses of opioids for background pain. This prospective study showed that in this population, BTcP prevalence was 69.8%. Many patients did not achieve a sufficient level of satisfaction with BTcP medications, particularly with oral morphine. Data also suggest that better optimization of background analgesia, though apparently acceptable, may limit the number of BTcP episodes.

Abstract

The aim of this study was to assess the prevalence and characteristics of breakthrough cancer pain (BTcP) in patients receiving low doses of opioids for background pain. A consecutive sample of advanced cancer patients receiving less than 60 mg/day of oral morphine equivalent (OME) was selected. Epidemiological data, background pain intensity, and current analgesic therapy were recorded. The presence of BTcP was diagnosed according to a standard algorithm. The number of BTcP episodes, intensity of BTcP, its predictability and triggers, onset duration, interference with daily activities, BTcP medications, satisfaction with BTcP medication, and time to meaningful pain relief were collected. A total of 126 patients were screened. The mean intensity of background pain was 2.71 (1.57), and the mean OME was 28.5 mg/day (SD15.8). BTP episodes were recorded in 88 patients (69.8%). The mean number/day of BTP episodes was 4.1 (SD 7.1, range 1–30). In a significant percentage of patients, BTcP was both predictable and unpredictable (23%). The BTcP onset was less than 20 min in the majority of patients. The mean duration of untreated episodes was 47.5 (SD 47.6) minutes. The mean time to meaningful pain relief after taking a BTcP medication was >20 min in 44.5% of patients. The efficacy of BTcP medication was not considered good in more than 63% of patients. Gender (females) (OR = 4.16) and lower Karnofsky (OR = 0.92) were independently associated with BTcP. A higher number of BTcP episodes/day was associated with gender (females) (p = 0.036), short duration of BTcP (p = 0.005), poorer efficacy of BTcP medication (none or mild) (p = 0.001), and late meaningful pain relief (p = 0.024). The poor efficacy of BTcP medication was independently associated with a higher number of episodes/day (OR = 0.22). In patients who were receiving low doses of opioids, BTcP prevalence was 69.8%. Many patients did not achieve a sufficient level of satisfaction with BTcP medications, particularly with oral morphine. Data also suggest that better optimization of background analgesia, though apparently acceptable, may limit the number of BTcP episodes.

Understanding the Chameleonic Breakthrough Cancer Pain

Breakthrough cancer pain (BTcP) is a variegated phenomenon, that often presents in different ways in each individual, and may change its presentation in the same individual during the course of disease. An appropriate assessment is fundamental for depicting the pattern of BTcP in individuals. This information is determinant for a personalised management of BTcP. The use of opioids as needed, is recommended for the management of BTcP. There are several options which should be chosen according to the individual pattern of BTcP. In general, a drug with a short onset and offset should be preferred. Although oral opioids may still have specific indications, fentanyl products have been found to be more rapid and effective, providing analgesia in 5-15 min. The most controversial point regards the opioid dose to be used. The presence of tolerance suggests using a dose that is proportional to the dose used for background analgesia. In contrast, regulatory studies have suggested using the minimal available dose to be titrated until the effective dose. Further large studies should definitely settle this never-ending question.

Morphine for the symptomatic reduction of chronic breathlessness: the case for controlled release

PURPOSE OF REVIEW

Clinicians who seek to reduce the symptomatic burden of chronic breathlessness by initiating regular low-dose morphine has the choice of immediate or sustained-release formulations - which will be better for this often frail population, and which has the more robust evidence to inform its prescription? Both formulations can be used.

RECENT FINDINGS

For chronic breathlessness, three factors consistently favour the use of regular, low-dose, sustained-release morphine over immediate-release formulations: SUMMARY: As the evidence base expands for the symptomatic reduction of chronic breathlessness, pharmacological interventions will play a part. Using the best available evidence underpins patient-centred approaches that seek to predictably maximize the net effect.As such, the weight of evidence in patient-centred clinical care favours the use of regular, low-dose sustained-release morphine for the symptomatic reduction of chronic breathlessness.

The Endless Question of Opioid Doses for Breakthrough Pain

This letter to the editor responds to comments in the still open debate regarding the use of breakthrough pain medications in cancer patients.