Clinically relevant concentrations of opioids for in vitro studies

OBJECTIVES

Numerous in vitro studies have evaluated the influence of opioids on many biological and immunological processes. The concentrations that have been used in these studies span a large range and often do not reflect levels that are present in the relevant patient groups. This article reviews the literature concerning the concentrations of opioids that are detected in patients so that the concentrations of opioids that are used for in vitro studies can better reflect those that are present clinically. This will enable scientists and clinicians to more effectively model and interpret potentially relevant clinical effects from in vitro studies.

METHODS

Data on the concentrations of six commonly used opioids from clinical studies in adults were collected by searching PubMed (Medline).

RESULTS

A total of 42 relevant studies were included in the review. Concentrations of the opioids from previous clinical studies were mostly between 1 and 10 ng/mL for buprenorphine, 1 and 10 ng/mL for fentanyl, 50 and 500 ng/mL for methadone, 25 and 250 ng/mL for morphine, 10 and 100 ng/mL for oxycodone, and 100 and 1,000 ng/mL for Tramadol and were dependent on the patient group and indication under investigation.

CONCLUSIONS

Concentrations of opioids used in vitro should include those that are present in the relevant clinical setting if the effects of opioids detected in vitro are to be of potential relevance to the clinical setting. Therefore, it is essential that these concentrations in the relevant clinical context(s) are known.

The impact of therapeutic opioid agonists on driving-related psychomotor skills assessed by a driving simulator or an on-road driving task: A systematic review

BACKGROUND

Driving cessation is associated with poor health-related outcomes. People with chronic diseases are often prescribed long-term opioid agonists that have the potential to impair driving. Studies evaluating the impact of opioids on driving-related psychomotor skills report contradictory results likely due to heterogeneous designs, assessment tools and study populations. A better understanding of the effects of regular therapeutic opioid agonists on driving can help to inform the balance between individual's independence and community safety.

AIM

To identify the literature assessing the impact of regular therapeutic opioid agonists on driving-related psychomotor skills for people with chronic pain or chronic breathlessness.

DESIGN

Systematic review reported in accordance with the Preferred Reporting Items for Systematic Review and Meta-analysis statement; PROSPERO Registration CRD42017055909.

DATA SOURCES

Six electronic databases and grey literature were systematically searched up to January, 2017. Inclusion criteria were as follows: (1) empirical studies reporting data on driving simulation, on-the-road driving tasks or driving outcomes; (2) people with chronic pain or chronic breathlessness; and (3) taking regular therapeutic opioid agonists. Critical appraisal used the National Institutes of Health's quality assessment tools.

RESULTS

From 3809 records screened, three studies matched the inclusion criteria. All reported data on people with chronic non-malignant pain. No significant impact of regular therapeutic opioid agonists on people's driving-related psychomotor skills was reported. One study reported more intense pain significantly worsened driving performance.

CONCLUSION

This systematic review does not identify impaired simulated driving performance when people take regular therapeutic opioid agonists for symptom control, although more prospective studies are needed.

The Association of Benzodiazepines and z-drugs with Mortality in Patients with Cancer: a Systematic Review

BACKGROUND

Benzodiazepines and Z-drugs are commonly used in patients with cancer for the management of symptoms such as anxiety, agitation and dyspnoea. Clinical staff, patients and relatives have concerns about the impact of these drugs on survival. This potentially decreases prescribing leading to suboptimal symptom control. The aim of this systematic review was to find and assimilate the evidence assessing the association of benzodiazepines and Z-drugs with survival in patients with cancer, to assist in clinical decision-making regarding the use of these drugs in cancer patients.

METHODS

Systematic review with narrative synthesis designed and conducted according to the recommendations set out in Preferred Reporting Items for Systematic Reviews and MetaAnalyses-Protocol (PRISMA-P) and PRISMA statements. The review protocol was registered on the PROSPERO prior to commencing the searches. The electronic databases MEDLINE, EMBASE, PsychINFO, Cochrane Library, AMED were searched and hand-searches were performed. Screening, extraction and quality assessment were performed in duplicate.

RESULTS

A total of 2257 unique records were identified, 116 full-text articles assessed for eligibility, 18 met the inclusion criteria. These contained data on 4117 patients with cancer. All studies were low or very-low quality. Most studies were conducted in patients in the last days/weeks of life. No study found an association between benzodiazepines and survival in patients with cancer.

CONCLUSIONS

There is no evidence demonstrating an association between benzodiazepines and survival in patients with cancer. These results should be interpreted with caution as all studies were low/very low quality, most did not report or account for other medications and did not have survival as a primary outcome. No study assessed the effect of long-term benzodiazepines on survival. Therefore, definitive conclusions regarding survival impact of benzodiazepine in patients with cancer can be made. Further investigation using high-quality long-term randomised control trials with survival as a primary endpoint are needed.

Updates in palliative care - overview and recent advancements in the pharmacological management of cancer pain

Pain is a common symptom in many types of cancer. Interdisciplinary team management, including pain assessment, explanation to the patient/family, treating the reversible, non-pharmacological treatments and reassessment are essential. This article focuses on the pharmacological management of cancer pain, and overviews and updates on the recent advances in this field. Both non-opioid and opioid analgesia as well as coanalgesics (adjuvants) are reviewed. Within non-opioid analgesia the risks of non-steroidal anti-inflammatory drugs (NSAIDs) are considered and recommendations for NSAIDs in patients at risk of gastrointestinal and cardiovascular toxicity are made. For opioid analgesics, side effects of opioids are discussed alongside practical guidance on opioid prescribing and converting between opioids. Newer drugs such as tapentadol are considered in this update. Amitriptyline, duloxetine, gabapentin and pregabalin, and the guidance for their use are reviewed in the coanalgesics (adjuvants) section.

Updates in palliative care - recent advancements in the pharmacological management of symptoms

Symptom management is an important part of both palliative care and end-of-life care. This article will examine the recent research evidence about drugs commonly used for symptom management in adult patients receiving palliative care. In particular, the management of symptoms where recent palliative care-based evidence has changed recommended practice will be reviewed. This includes: breathlessness, delirium, nausea and vomiting in bowel obstruction, opioid-induced constipation and upper respiratory tract secretions. For each symptom, a review of recent pharmacological evidence has been undertaken, with emphasis on potential important changes to physicians' practice.

Pharmacovigilance in Hospice/Palliative Care: Net Effect of Haloperidol for Nausea or Vomiting

BACKGROUND

Haloperidol is widely prescribed as an antiemetic in patients receiving palliative care, but there is limited evidence to support and refine its use.

OBJECTIVE

To explore the immediate and short-term net clinical effects of haloperidol when treating nausea and/or vomiting in palliative care patients.

DESIGN

A prospective, multicenter, consecutive case series.

SETTING/SUBJECTS

Twenty-two sites, five countries: consultative, ambulatory, and inpatient services.

MEASUREMENTS

When haloperidol was started in routine care as an antiemetic, data were collected at three time points: baseline; 48 hours (benefits); day seven (harms). Clinical effects were assessed using the National Cancer Institute's Common Terminology Criteria for Adverse Events (NCI CTCAE).

RESULTS

Data were collected (May 2014-March 2016) from 150 patients: 61% male; 86% with cancer; mean age 72 (standard deviation 11) years and median Australian-modified Karnofsky Performance Scale 50 (range 10-90). At baseline, nausea was moderate (88; 62%) or severe (11; 8%); 145 patients reported vomiting, with a baseline NCI CTCAE vomiting score of 1.0. The median (range) dose of haloperidol was 1.5 mg/24 hours (0.5-5 mg/24 hours) given orally or parenterally. Five patients (3%) died before further data collection. At 48 hours, 114 patients (79%) had complete resolution of their nausea and vomiting, with greater benefit seen in the resolution of nausea than vomiting. At day seven, 37 (26%) patients had a total of 62 mild/moderate harms including constipation 25 (40%); dry mouth 13 (21%); and somnolence 12 (19%).

CONCLUSIONS

Haloperidol as an antiemetic provided rapid net clinical benefit with low-grade, short-term harms.

Influence of opioids on immune function in patients with cancer pain: from bench to bedside

In patients with cancer, opioids are principally used for the management of acute surgical and chronic cancer-related pain. However, opioids have many non-analgesic effects, including direct and indirect effects on cancer cells and on anti-tumour immunity (NK cells, macrophages and T-cells). Direct effects on immune cells are manifested via opioid and non-opioid toll-like receptors, whereas indirect effects are manifested via the sympathetic nervous system and hypothalamic-pituitary-adrenal axis. Opioids can also decrease/alter immune cell infiltration into the tumour micro-environment. Animal models have shown that this is not a class effect, in that morphine and fentanyl suppress NK cell cytotoxicity; buprenorphine does not affect NK cell cytotoxicity, whereas tramadol increases NK cell cytotoxicity, reducing metastasis. In healthy individuals, morphine suppresses and fentanyl enhances NK cell cytotoxicity. In patients undergoing surgery, fentanyl decreased and tramadol increased NK cell cytotoxicity; clinical outcomes were not determined. Meta-analyses of opioid-sparing surgical studies report an association between improved recurrence-free and/or overall survival with regional/neuraxial anaesthesia compared with systemic opioids. In patients receiving opioids for non-surgical cancer-related pain, morphine has variable effects on immunity; clinical outcomes were not assessed. Although there is a potential association between systemic opioid administration and shorter survival in cancer patients with a prognosis of months to years, studies have not been designed to primarily assess survival, as a consequence of which causality cannot be apportioned. Pain is immunosuppressive, so analgesia is important. Opioids for cancer-related pain will continue to be recommended until definitive data on the effects of opioids on clinical outcomes in specific patient groups becomes available.

LINKED ARTICLES

This article is part of a themed section on Emerging Areas of Opioid Pharmacology. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.14/issuetoc.

A pilot study of interprofessional palliative care education of medical students in the UK and USA

Background

Educating medical students to care for patients at the end-of-life is increasingly recognised as an essential component of training. Traditionally, medical student programmes are run by doctors, but patient care is delivered by an interprofessional team. Our programmes in the UK and USA independently developed a teaching experience led by an interprofessional team of palliative care health professionals.

Objectives

This study explores the palliative care health professionals’ perceptions, regarding their unique role in medical student palliative care education.

Methods

This is the first study to ascertain views of an interprofessional team delivering palliative care education to medical students. Focus groups enable interaction between members of the group as well as the generation of consensus of comments among group members.

Results

Two major themes were identified: perceived benefits and value of the experience, and the challenges and lessons learnt from the experiences.

Conclusions

Despite different structures and settings, this experiential learning in palliative care provided a rewarding interprofessional experience that has historically been difficult to achieve.

Communication and support from health-care professionals to families, with dependent children, following the diagnosis of parental life-limiting illness: A systematic review

BACKGROUND

Communication between parents and their children about parental life-limiting illness is stressful. Parents want support from health-care professionals; however, the extent of this support is not known. Awareness of family's needs would help ensure appropriate support.

AIM

To find the current literature exploring (1) how parents with a life-limiting illness, who have dependent children, perceive health-care professionals' communication with them about the illness, diagnosis and treatments, including how social, practical and emotional support is offered to them and (2) how this contributes to the parents' feelings of supporting their children.

DESIGN

A systematic literature review and narrative synthesis.

DATA SOURCES

Embase, MEDLINE, PsycINFO, CINAHL and ASSIA ProQuest were searched in November 2015 for studies assessing communication between health-care professionals and parents about how to talk with their children about the parent's illness.

RESULTS

There were 1342 records identified, five qualitative studies met the inclusion criteria (55 ill parents, 11 spouses/carers, 26 children and 16 health-care professionals). Parents wanted information from health-care professionals about how to talk to their children about the illness; this was not routinely offered. Children also want to talk with a health-care professional about their parents' illness. Health-care professionals are concerned that conversations with parents and their children will be too difficult and time-consuming.

CONCLUSION

Parents with a life-limiting illness want support from their health-care professionals about how to communicate with their children about the illness. Their children look to health-care professionals for information about their parent's illness. Health-care professionals, have an important role but appear reluctant to address these concerns because of fears of insufficient time and expertise.

Implementation of the Needs Assessment Tool for patients with interstitial lung disease (NAT:ILD): facilitators and barriers

A Needs Assessment Tool (NAT) was developed previously to help clinicians identify the supportive/palliative needs of people with interstitial lung disease (ILD) (NAT:ILD). This letter presents barriers and facilitators to clinical implementation. Data from (1) a focus group of respiratory clinicians and (2) an expert consensus group (respiratory and palliative clinicians, academics, patients, carers) were analysed using Framework Analysis. Barriers related to resources and service reconfiguration, and facilitators to clinical need, structure, objectiveness, flexibility and benefits of an ‘aide-memoire’. Identified training needs included communication skills and local service knowledge. The NAT:ILD was seen as useful, necessary and practical in everyday practice.

Somatostatin Analogues Compared With Placebo and Other Pharmacologic Agents in the Management of Symptoms of Inoperable Malignant Bowel Obstruction: A Systematic Review

CONTEXT

Somatostatin analogues are commonly used to relieve symptoms in malignant bowel obstruction (MBO) but are more expensive than other antisecretory agents.

OBJECTIVES

To evaluate the evidence of effectiveness of somatostatin analogues compared with placebo and/or other pharmacologic agents in relieving vomiting in patients with inoperable MBO.

METHODS

MEDLINE, EMBASE, CINAHL, and The Cochrane Controlled Trials Register databases were systematically searched; reference lists of relevant articles were hand searched. Cochrane risk of bias tool was used.

RESULTS

The search identified 420 unique studies. Seven randomized controlled trials (RCTs) met the inclusion criteria (six octreotide studies and one lanreotide); 220 people administered somatostatin analogues and 207 placebo or hyoscine butylbromide. Three RCTs compared a somatostatin analogue with placebo and four with hyoscine butylbromide. Two adequately powered multicenter RCTs with a low Cochrane risk of bias reported no significant difference between somatostatin analogues and placebo in their primary end points. Four RCTs with a high/unclear Cochrane risk of bias reported that somatostatin analogues were more effective than hyoscine butylbromide in reducing vomiting.

CONCLUSION

There is low-level evidence of benefit with somatostatin analogues in the symptomatic treatment of MBO. However, high-level evidence from trials with low risk of bias found no benefit of somatostatin analogues for their primary outcome. There is debate regarding the clinically relevant study end point for symptom control in MBO and when it should be measured. The role of somatostatin analogues in this clinical situation requires further adequately powered, well-designed trials with agreed clinically important end points and measures.

Assessment of the appropriateness of naloxone administration to patients receiving long-term opioid therapy

BACKGROUND

The most dangerous adverse effect of opioids is respiratory depression. Naloxone is used to reverse this, although in patients receiving long-term opioid therapy it can cause acute opioid withdrawal and opioid-refractory pain.

OBJECTIVE

To determine if naloxone is appropriately administered to patients receiving long-term opioid therapy.

METHODS

This retrospective case series based on chart reviews systematically identified patients over one year in a district general hospital. All patients aged 18 years or older receiving long-term opioid therapy admitted to medicine, surgery or the high dependency unit who were administered naloxone during their admission were included.

RESULTS

A total of 1206 patient drug administration records were reviewed. Sixteen patients receiving long-term opioid therapy were administered naloxone. Twelve of these did not have opioid-induced respiratory depression and four did not have respiratory rate and oxygen saturations documented in the medical notes. All naloxone doses administered were higher than those recommended by national guidelines for this patient group.

CONCLUSIONS

No patient receiving long-term opioid therapy who was administered naloxone had evidence of respiratory depression. More thorough assessment and documentation are needed. Verbal and physical stimulation as well as oxygenation should be considered prior to naloxone administration; this should be followed by close observation, hydration, renal function tests and opioid dose review.

The Adaptation, Face, and Content Validation of a Needs Assessment Tool: Progressive Disease for People with Interstitial Lung Disease

BACKGROUND

Irrreversible interstitial lung disease (ILD) is associated with high morbidity and mortality. Palliative care needs of patients and caregivers are not routinely assessed; there is no tool to identify needs and triage support in clinical practice.

OBJECTIVE

The study objective was to adapt and face/content validate a palliative needs assessment tool for people with ILD.

METHODS

The Needs Assessment Tool: Progressive Disease-Cancer (NAT:PD-C) was adapted to reflect the palliative care needs identified from the ILD literature and patient/caregiver interviews. Face and content validity of the NAT:PD-ILD was tested using patient/caregiver focus groups and an expert consensus group. Participants in the study were two English tertiary health care trusts' outpatients clinics. There were four focus groups: two patient (n = 7; n = 4); one caregiver (n = 3); and one clinician (n = 8). There was a single caregiver interview, and an expert consensus group-academics (n = 3), clinicians (n = 9), patients (n = 4), and caregivers (n = 2). Each item in the tool was revised as agreed by the groups. Expert consensus was reached.

RESULTS

Overall, the tool reflected participants' experience of ILD. Each domain was considered relevant. Adaptations were needed to represent the burden of ILD: respiratory symptoms (especially cough) and concerns about sexual activity were highlighted. All emphasized assessment of caregiver need as critical, and the role of caregivers in clinical consultations.

CONCLUSIONS

The NAT:PD-ILD appears to have face and content validity. The inclusion of the family caregiver in the consultation as someone with their own needs as well as a source of information was welcomed. Reliability testing and construct validation of the tool are ongoing.

Constipation: opioid antagonists in people prescribed opioids

INTRODUCTION

Constipation is a common adverse effect of opioids. As an example, constipation is reported in 52% of people with advanced malignancy, and this figure rises to 87% in people who are terminally ill and taking opioids. There is no reason to believe that people with chronic non-malignant disease who are prescribed opioids will be any less troubled by this adverse effect.

METHODS AND OUTCOMES

We conducted a systematic overview and aimed to answer the following clinical question: What are the effects of opioid antagonists for constipation in people prescribed opioids? The population we studied included people with any condition, although most studies were in people with cancer pain. We searched Medline, Embase, The Cochrane Library, and other important databases up to May 2014 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review).

RESULTS

At this update, searching of electronic databases retrieved 162 studies. After deduplication and removal of conference abstracts, 84 records were screened for inclusion in the review. Appraisal of titles and abstracts led to the exclusion of 47 studies and the further review of 37 full publications. Of the 37 full articles evaluated, two systematic reviews and one RCT were included at this update. We performed a GRADE evaluation for three PICO combinations.

CONCLUSIONS

In this systematic overview we categorised the efficacy for three interventions based on information relating to the effectiveness of alvimopan, methylnaltrexone, and naloxone.