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Journal of Palliative Medicine Jul 2015Subcutaneous methylnaltrexone (MNTX), dosed based on body weight, is efficacious and well tolerated in inducing bowel movements in patients with advanced illness and... (Randomized Controlled Trial)
Randomized Controlled Trial
Fixed-Dose Subcutaneous Methylnaltrexone in Patients with Advanced Illness and Opioid-Induced Constipation: Results of a Randomized, Placebo-Controlled Study and Open-Label Extension.
BACKGROUND
Subcutaneous methylnaltrexone (MNTX), dosed based on body weight, is efficacious and well tolerated in inducing bowel movements in patients with advanced illness and opioid-induced constipation (OIC); however, fixed-dose administration of MNTX may improve ease of administration.
OBJECTIVE
The study objective was to assess safety and efficacy of fixed-dose MNTX in two phase 4 trials.
METHODS
In a double-blind, randomized, placebo-controlled trial (RCT), patients with advanced illness and OIC received MNTX (8 mg or 12 mg by body weight [38 kg to <62 kg or ≥62 kg, respectively]) or placebo every other day (QOD) for two weeks. Patients completing the RCT could enroll in an open-label extension (OLE) study with MNTX administered as needed (PRN). The primary endpoint was percentage of patients with a rescue-free bowel movement (RFBM) within four hours after ≥2 of the first 4 doses in the first week.
RESULTS
In the RCT, 116 and 114 patients received MNTX and placebo, respectively, and 149 patients continued to the OLE study. The percentage of patients achieving primary endpoint was 62.9% and 9.6% for MNTX and placebo groups, respectively (p<0.0001). Median time to RFBM after the first dose was 0.8 hour and 23.6 hours in MNTX and placebo groups, respectively (p<0.0001). Efficacy results during the OLE study were consistent with the RCT. MNTX demonstrated a favorable safety profile in the RCT and OLE study.
CONCLUSION
Fixed-dose MNTX administered QOD in the RCT and PRN in the OLE study demonstrated robust efficacy and was well tolerated in treating OIC in patients with advanced illness.
Topics: Aged; Analgesics, Opioid; Constipation; Double-Blind Method; Female; Humans; Injections, Subcutaneous; Male; Middle Aged; Naltrexone; Narcotic Antagonists; Patient Safety; Placebos; Quaternary Ammonium Compounds; Severity of Illness Index
PubMed: 25973526
DOI: 10.1089/jpm.2014.0362 -
The Cochrane Database of Systematic... May 2015This article describes the second update of a Cochrane review on the effectiveness of laxatives for the management of constipation in people receiving palliative care.... (Review)
Review
BACKGROUND
This article describes the second update of a Cochrane review on the effectiveness of laxatives for the management of constipation in people receiving palliative care. Previous versions were published in 2006 and 2010 where we also evaluated trials of methylnaltrexone; these trials have been removed as they are included in another review in press. In these earlier versions, we drew no conclusions on individual effectiveness of different laxatives because of the limited number of evaluations. This is despite constipation being common in palliative care, generating considerable suffering due to the unpleasant physical symptoms and the availability of a wide range of laxatives with known differences in effect in other populations.
OBJECTIVES
To determine the effectiveness and differential efficacy of laxatives used to manage constipation in people receiving palliative care.
SEARCH METHODS
We searched the Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library), MEDLINE, EMBASE, CINAHL and Web of Science (SCI & CPCI-S) for trials to September 2014.
SELECTION CRITERIA
Randomised controlled trials (RCTs) evaluating laxatives for constipation in people receiving palliative care.
DATA COLLECTION AND ANALYSIS
Two authors assessed trial quality and extracted data. The appropriateness of combining data from the studies depended upon clinical and outcome measure homogeneity.
MAIN RESULTS
We identified five studies involving the laxatives lactulose, senna, co-danthramer, misrakasneham, docusate and magnesium hydroxide with liquid paraffin. Overall, the study findings were at an unclear risk of bias. As all five studies compared different laxatives or combinations of laxatives, it was not possible to perform a meta-analysis. There was no evidence on whether individual laxatives were more effective than others or caused fewer adverse effects.
AUTHORS' CONCLUSIONS
This second update found that laxatives were of similar effectiveness but the evidence remains limited due to insufficient data from a few small RCTs. None of the studies evaluated polyethylene glycol or any intervention given rectally. There is a need for more trials to evaluate the effectiveness of laxatives in palliative care populations. Extrapolating findings on the effectiveness of laxatives evaluated in other populations should proceed with caution. This is because of the differences inherent in people receiving palliative care that may impact, in a likely negative way, on the effect of a laxative.
Topics: Analgesics, Opioid; Anthraquinones; Cathartics; Constipation; Humans; Lactulose; Magnesium Hydroxide; Naltrexone; Palliative Care; Paraffin; Quaternary Ammonium Compounds; Randomized Controlled Trials as Topic; Senna Extract
PubMed: 25967924
DOI: 10.1002/14651858.CD003448.pub4 -
Drug Design, Development and Therapy 2015Opioid-induced bowel dysfunction (OIBD) comprises gastrointestinal (GI) symptoms, including dry mouth, nausea, vomiting, gastric stasis, bloating, abdominal pain, and... (Review)
Review
Opioid-induced bowel dysfunction (OIBD) comprises gastrointestinal (GI) symptoms, including dry mouth, nausea, vomiting, gastric stasis, bloating, abdominal pain, and opioid-induced constipation, which significantly impair patients' quality of life and may lead to undertreatment of pain. Traditional laxatives are often prescribed for OIBD symptoms, although they display limited efficacy and exert adverse effects. Other strategies include prokinetics and change of opioids or their administration route. However, these approaches do not address underlying causes of OIBD associated with opioid effects on mostly peripheral opioid receptors located in the GI tract. Targeted management of OIBD comprises purely peripherally acting opioid receptor antagonists and a combination of opioid receptor agonist and antagonist. Methylnaltrexone induces laxation in 50%-60% of patients with advanced diseases and OIBD who do not respond to traditional oral laxatives without inducing opioid withdrawal symptoms with similar response (45%-50%) after an oral administration of naloxegol. A combination of prolonged-release oxycodone with prolonged-release naloxone (OXN) in one tablet (a ratio of 2:1) provides analgesia with limited negative effect on the bowel function, as oxycodone displays high oral bioavailability and naloxone demonstrates local antagonist effect on opioid receptors in the GI tract and is totally inactivated in the liver. OXN in daily doses of up to 80 mg/40 mg provides equally effective analgesia with improved bowel function compared to oxycodone administered alone in patients with chronic non-malignant and cancer-related pain. OIBD is a common complication of long-term opioid therapy and may lead to quality of life deterioration and undertreatment of pain. Thus, a complex assessment and management that addresses underlying causes and patomechanisms of OIBD is recommended. Newer strategies comprise methylnaltrexone or OXN administration in the management of OIBD, and OXN may be also considered as a preventive measure of OIBD development in patients who require opioid administration.
Topics: Analgesics, Opioid; Gastrointestinal Diseases; Gastrointestinal Motility; Humans; Narcotic Antagonists
PubMed: 25931815
DOI: 10.2147/DDDT.S32684 -
Journal of Palliative Medicine Jul 2015Opioid-induced constipation (OIC) is common among children and adolescents and young adults (AYA) with progressive incurable cancer. Although methylnaltrexone is a...
BACKGROUND
Opioid-induced constipation (OIC) is common among children and adolescents and young adults (AYA) with progressive incurable cancer. Although methylnaltrexone is a successful treatment for OIC in adult cancer patients, no case series has established its safety and efficacy in pediatric cancer patients.
OBJECTIVES
The aim of the study was to describe the safety and efficacy of methylnaltrexone use for OIC in children and AYA with progressive incurable cancer at the end of life in the inpatient and outpatient settings.
METHODS
We conducted a retrospective review of medical records of children and AYA with progressive incurable cancer who received methylnaltrexone at our institution from May 2008 to June 2013. Pharmacy data were reviewed for each patient and a chart review was performed for documentation of laxation and side effects.
RESULTS
Of the 9 patients (age range: 17 months to 21 years) with progressive incurable cancer who developed OIC, 7 (78%) had laxation after methylnaltrexone administration (0.15 mg/kg/dose). Of these 7 patients, 5 (71%) had laxation with the first dose, and 5 (71%) who responded had a continued response to repeated doses. The longest a patient regularly received methylnaltrexone was 9 months. Of 5 patients with intraabdominal disease, 4 (80%) had laxation. There were no negative side effects in any of the patients. Also, there was no increase in pain either qualitatively or by pain score.
CONCLUSIONS
Methylnaltrexone appears to be safe and efficacious in treating OIC in children and AYA with progressive incurable cancer. Methylnaltrexone was tolerated in both the inpatient and outpatient settings and with repeated dosing.
Topics: Adolescent; Analgesics, Opioid; Child; Child, Preschool; Constipation; Double-Blind Method; Female; Humans; Infant; Male; Medical Audit; Naltrexone; Narcotic Antagonists; Neoplasms; Quaternary Ammonium Compounds; Retrospective Studies; Terminally Ill; Young Adult
PubMed: 25927665
DOI: 10.1089/jpm.2014.0364 -
PloS One 2015The dormancy of tumor cells is a major problem in chemotherapy, since it limits the therapeutic efficacy of anti-tumor drugs that only target dividing cells. One...
The dormancy of tumor cells is a major problem in chemotherapy, since it limits the therapeutic efficacy of anti-tumor drugs that only target dividing cells. One potential way to overcome chemo-resistance is to "wake up" these dormant cells. Here we show that the opioid antagonist methylnaltrexone (MNTX) enhances the effect of docetaxel (Doc) by blocking a cell growth-suppressive pathway. We found that PENK, which encodes opioid growth factor (OGF) and suppresses cell growth, is predominantly expressed in diffuse-type gastric cancers (GCs). The blockade of OGF signaling by MNTX releases cells from their arrest and boosts the effect of Doc. In comparison with the use of Doc alone, the combined use of Doc and MNTX significantly prolongs survival, alleviates abdominal pain, and diminishes Doc-resistant spheroids on the peritoneal membrane in model mice. These results suggest that blockade of the pathways that suppress cell growth may enhance the effects of anti-tumor drugs.
Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Cell Cycle; Cell Proliferation; Docetaxel; Drug Synergism; Growth Inhibitors; Humans; Mice; Naltrexone; Narcotic Antagonists; Quaternary Ammonium Compounds; Receptors, Opioid; Stomach Neoplasms; Taxoids
PubMed: 25853862
DOI: 10.1371/journal.pone.0123407 -
British Journal of Anaesthesia Mar 2015Intrathecal morphine-induced pruritus is a very common side-effect that is difficult to prevent or treat. Central and peripheral mechanisms are believed to be involved.... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Intrathecal morphine-induced pruritus is a very common side-effect that is difficult to prevent or treat. Central and peripheral mechanisms are believed to be involved. The aim of this study was to determine if a peripherally acting, μ-opioid antagonist would reduce morphine-induced pruritus.
METHODS
We conducted a multicentre, randomized, blinded, placebo-controlled trial of women having elective Caesarean section under spinal anaesthesia with intrathecal morphine 100 μg. After delivery, participants received either subcutaneous methylnatrexone bromide 12 mg (MNTX group, n=69) or saline (placebo group, n=68). Pruritus, nausea, pain, analgesic use, and side-effects were assessed at 2, 4, 8, and 24 h. The primary outcome was the severity of pruritus (0-10 score).
RESULTS
One hundred and thirty-seven women completed the study, with five major protocol violations. There was no statistically significant difference between the MNTX and placebo groups for the median (IQR) pruritus AUC scores [24 (9-47) vs 36 (11-68), median difference 8.5, 95% confidence interval (CI) 0-20, P=0.09] or the worst pruritus score [3 (2-7) vs 5 (2-6), median difference 1, 95% CI 0-2, P=0.24]. The incidence of pruritus was 84% in the MNTX group and 88% in the placebo group (P=0.48). Analgesic and gastrointestinal outcomes did not significantly differ between the groups.
CONCLUSIONS
A single dose of subcutaneous methylnaltrexone bromide 12 mg did not reduce the overall severity or incidence of pruritus. In this study, treatment with a peripherally acting μ-opioid antagonist was generally ineffective against intrathecal morphine-induced pruritus, but a small clinical effect cannot be excluded.
CLINICAL TRIAL REGISTRATION
Australian New Zealand Clinical Trials Registry (ACTRN12611000345987).
Topics: Adult; Analgesia, Obstetrical; Analgesics, Opioid; Anesthesia, Spinal; Australia; Cesarean Section; Female; Humans; Middle Aged; Morphine; Naltrexone; Narcotic Antagonists; Postoperative Complications; Pregnancy; Pruritus; Quaternary Ammonium Compounds; Singapore; Treatment Outcome; United States; Young Adult
PubMed: 25567476
DOI: 10.1093/bja/aeu410 -
Clinical and Experimental... 2014Opioid-induced bowel dysfunction (OIBD) is a burdensome condition which limits the therapeutic benefit of analgesia. It affects the entire gastrointestinal tract,... (Review)
Review
Opioid-induced bowel dysfunction (OIBD) is a burdensome condition which limits the therapeutic benefit of analgesia. It affects the entire gastrointestinal tract, predominantly by activating opioid receptors in the enteric nervous system, resulting in a wide range of symptoms, such as reflux, bloating, abdominal cramping, hard, dry stools, and incomplete evacuation. The majority of studies evaluating OIBD focus on constipation experienced in approximately 60% of patients. Nevertheless, other presentations of OIBD seem to be equally frequent. Furthermore, laxative treatment is often insufficient, which in many patients results in decreased quality of life and discontinuation of opioid treatment. Novel mechanism-based pharmacological approaches targeting the gastrointestinal opioid receptors have been marketed recently and even more are in the pipeline. One strategy is prolonged release formulation of the opioid antagonist naloxone (which has limited systemic absorption) and oxycodone in a combined tablet. Another approach is peripherally acting, μ-opioid receptor antagonists (PAMORAs) that selectively target μ-opioid receptors in the gastrointestinal tract. However, in Europe the only PAMORA approved for OIBD is the subcutaneously administered methylnaltrexone. Alvimopan is an oral PAMORA, but only approved in the US for postoperative ileus in hospitalized patients. Finally, naloxegol is a novel, oral PAMORA expected to be approved soon. In this review, the prevalence and pathophysiology of OIBD is presented. As PAMORAs seem to be a promising approach, their potential effect is reviewed with special focus on naloxegol's pharmacological properties, data on safety, efficacy, and patient-focused perspectives. In conclusion, as naloxegol is administered orally once daily, has proven efficacious compared to placebo, has an acceptable safety profile, and can be used as add-on to existing pain treatment, it is a welcoming addition to the targeted treatment possibilities for OIBD.
PubMed: 25278772
DOI: 10.2147/CEG.S52097 -
BMC Palliative Care 2014Opioid-induced constipation (OIC) is one of the major symptoms in palliative care with a prevalence of 30-50%. Methylnaltrexone for the treatment of OIC is significantly...
Clinical evaluation of the efficacy of methylnaltrexone in resolving constipation induced by different opioid subtypes combined with laboratory analysis of immunomodulatory and antiangiogenic effects of methylnaltrexone.
BACKGROUND
Opioid-induced constipation (OIC) is one of the major symptoms in palliative care with a prevalence of 30-50%. Methylnaltrexone for the treatment of OIC is significantly more effective than placebo, but only in about fifty percent of the patients regardless of dose increase. Dose increases cause increased toxicity without additional efficacy, and are therefore not recommended. While methylnaltrexone is a μ-receptor antagonist, only a few opioids are solely μ-receptor agonists. Therefore, the response to methylnaltrexone may be determined by the receptor-profile of a specific opioid. In addition, methylnaltrexone may also affect the immune system and angiogenesis as was found in pre-clinical studies. Primary aim of this study is to determine differences in the efficacy of methylnaltrexone prescribed to resolve opioid induced constipation between three commonly used opioid subtypes: morphine sulphate, oxycodone and fentanyl. Secondary aim is to explore potential immunomodulatory and antiangiogenic effects of methylnaltrexone.
METHODS
In this multi-center, prospective, parallel group trial we will evaluate the efficacy of methylnaltrexone in resolving OIC occurring as a side effect of the most common opioid subtypes: morphine, oxycodone and fentanyl. In total 195 patients with OIC despite prophylactic laxatives will receive methylnaltrexone every other day up to fourteen days. Patients will report its effect in a laxation diary. Group allocation is based on the opioid type the patient is using. At the start and end of the study period patients complete the Bowel Function Index questionnaire. A subgroup of the patients will donate blood for analysis of immunomodulatory- and anti-angiogenic effects of methylnaltrexone.
DISCUSSION
In this study we aim to determine the efficacy of methylnaltrexone per opioid subtype to reduce constipation. We expect that the outcome of this study will improve the clinical use of methylnaltraxone.
TRIAL REGISTRATION
This trial is registered at clinicaltrials.gov: NCT01955213 and in the Dutch trial register: NTR4272.
PubMed: 25165428
DOI: 10.1186/1472-684X-13-42 -
British Journal of Anaesthesia Jul 2014We and others have previously demonstrated that the μ-opioid receptor (MOR) is overexpressed in several human malignancies. There is a seven-fold increase in MOR in...
BACKGROUND
We and others have previously demonstrated that the μ-opioid receptor (MOR) is overexpressed in several human malignancies. There is a seven-fold increase in MOR in cell lines of human lung cancer. In animal models, overexpression of MOR promotes tumour growth and metastasis. We, therefore, examined whether MOR expression is increased in metastatic lung cancer.
METHODS
In this study, we examined the association between MOR expression and metastasis in archived biopsy samples from patients with lung cancer. Paraffin-embedded patient material was stained using MOR antibody and scored qualitatively by two independent pathologists using a four-point scale.
RESULTS
In human lung cancer and normal adjacent lung samples obtained from 34 lung cancer patients, MOR expression was increased significantly in cancer samples from patients with lung cancer compared with adjacent control tissue (P=0.0242). When the samples from patients with metastatic lung cancer were separated from the cohort of the total number of patients with lung cancer, we observed an approximately two-fold increase in MOR expression (P=0.0013).
CONCLUSIONS
The association between the expression of MOR and the progression of the tumour is consistent with the hypothesis of a direct effect of MOR on cancer progression.
Topics: Aged; Aged, 80 and over; Biopsy; Carcinoma, Non-Small-Cell Lung; Disease Progression; Female; Humans; Lung Neoplasms; Lymphatic Metastasis; Male; Middle Aged; Neoplasm Proteins; Neoplasm Staging; Receptors, Opioid, mu
PubMed: 24920011
DOI: 10.1093/bja/aeu165 -
Gastroenterology Research and Practice 2014Although opioids offer potent analgesia for severe acute and chronic noncancer pain, adverse gastrointestinal effects potentially undermine their clinical utility. In... (Review)
Review
Although opioids offer potent analgesia for severe acute and chronic noncancer pain, adverse gastrointestinal effects potentially undermine their clinical utility. In particular, between 40% and 95% of patients develop opioid-induced constipation (OIC). Therefore, there is a consensus that patients should commence laxatives at the start of opioid therapy and continue throughout treatment. Nevertheless, laxatives are not routinely coprescribed with opioids. Even when concurrent laxatives are prescribed, approximately half the patients treated for OIC do not achieve the desired improvement. Moreover, laxatives do not target the underlying cause of OIC (opioid binding to the μ -receptors in the enteric system) and as such are not very effective at managing OIC. The failure of lifestyle modification and laxatives to treat adequately many cases of OIC led to the concurrent use of peripherally acting opioid antagonists (such as methylnaltrexone bromide and naloxone) to reduce the incidence of gastrointestinal adverse events without compromising analgesia. Judicious use of the various options to manage OIC should allow more patients to benefit from opioid analgesia. Therefore, this paper reviews the causes, consequences, and management of OIC to help clinicians optimise opioid analgesia.
PubMed: 24883055
DOI: 10.1155/2014/141737