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N Irwin M, A Cooke D, Berland D, D Marshall V, A Smith M. Efficacy and Safety of Low Dose Naltrexone for Chronic Pain. J Pain Palliat Care Pharmacother 2024; 38:13-19. [PMID: 38301136 DOI: 10.1080/15360288.2024.2302550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 12/28/2023] [Indexed: 02/03/2024]
Abstract
Naltrexone is a mu-opioid receptor antagonist increasingly used as an analgesic for chronic pain at low doses. This retrospective, observational cohort study was conducted at an academic medical center to evaluate low-dose naltrexone (LDN) efficacy and describe its use in routine clinical practice. Adults receiving LDN, doses <10 mg for ≥1 month, seen at an outpatient pain clinic from January 1, 2014 to April 1, 2022 were included. The primary outcome was change in the Pain, Enjoyment of Life, and General Activity (PEG) score after LDN. Thirty-one patients were included. Median age was 50 years and 71% were female. Median duration of pain at baseline was 5 years. Mean PEG scores were 7.27 ± 1.39 and 6.62 ± 2.04 at baseline and follow-up, respectively. Mean difference was 0.66 (95% CI [0.10-1.21], p = 0.022). Eighty-seven percent (27) of patients discontinued LDN, 52% (16) for lack of benefit, 23% (7) for loss of benefit, 10% (3) for side effects, and 3% (1) for other reasons. Seven (23%) reported side effects. LDN was associated with a statistically significant reduction in PEG in adult chronic pain patients, however the clinical significance is unclear as over 75% of patients discontinued LDN due to lack of benefit.
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Affiliation(s)
- Madison N Irwin
- Clinical Pharmacy, University of Michigan College of Pharmacy, Ann Arbor, Michigan, USA
- University of Michigan Health Department of Pharmacy, Ann Arbor, Michigan, USA
| | - David A Cooke
- University of Michigan Health System, Division of General Medicine, Ann Arbor, Michigan, USA
| | - Daniel Berland
- University of Michigan Health System, Division of General Medicine, Ann Arbor, Michigan, USA
| | - Vincent D Marshall
- Clinical Pharmacy, University of Michigan College of Pharmacy, Ann Arbor, Michigan, USA
| | - Michael A Smith
- Clinical Pharmacy, University of Michigan College of Pharmacy, Ann Arbor, Michigan, USA
- University of Michigan Health Department of Pharmacy, Ann Arbor, Michigan, USA
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2
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Stallkamp Tidd SJ, Cantrell C, Greene BD, Wilson R. Low-Dose Naltrexone Use in Postural Orthostatic Tachycardia Syndrome: A Case Series. Cureus 2023; 15:e43426. [PMID: 37706146 PMCID: PMC10497067 DOI: 10.7759/cureus.43426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/12/2023] [Indexed: 09/15/2023] Open
Abstract
Introduction In recent years, low-dose naltrexone has emerged as a novel off-label therapy for many chronic conditions including postural orthostatic tachycardia syndrome (POTS), however, there is little evidence for its efficacy. Methods In this institutional review board (IRB)-approved case series, the charts of six tilt table-confirmed patients with POTS who underwent a trial of low-dose naltrexone (LDN) at our institution were reviewed. Medical history, subjective description of symptom severity, the continuation of therapy, tolerability, and scores on patient-reported outcome measures (Patient-Reported Outcomes Measurement Information System {PROMIS} Fatigue, PROMIS physical and mental health, Generalized Anxiety Disorder Assessment {GAD}-7, Patient Health Questionnaire {PHQ}-9, and Composite Autonomic Symptom Score {COMPASS}) were collected at therapy initiation and six to 12 months after the start of LDN. Results Three out of six reviewed patients reported an improvement in their POTS after the initiation of LDN. Two patients discontinued the therapy due to a lack of perceived benefit. No side effects or adverse outcomes were reported. The patient-reported outcome measures of PROMIS Fatigue, PROMIS physical and mental health, GAD-7, PHQ-9, and COMPASS showed inconsistent changes over the course of therapy, with some patients showing improvement or stability and others showing worsening. The small sample size and incomplete response rate did not allow for extensive statistical analysis. Conclusion As seen in its use in other conditions, LDN appears to have a favorable safety and side effect profile in patients with POTS but has little evidence for efficacy. Although some patients noted benefit, patient-reported outcome measures show a variable response profile. High-quality randomized controlled trials are needed to determine if the treatment is efficacious and should be used outside of a trial basis.
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Affiliation(s)
| | - Christopher Cantrell
- Neurology, Cleveland Clinic Lerner College of Medicine, Cleveland Clinic, Cleveland, USA
| | - Brady D Greene
- Neurology, Cleveland Clinic Lerner College of Medicine, Cleveland Clinic, Cleveland, USA
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3
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Bested K, Jensen LM, Andresen T, Tarp G, Skovbjerg L, Johansen TS, Schmedes AV, Storgaard IK, Madsen JS, Werner MU, Bendiksen A. Low-dose naltrexone for treatment of pain in patients with fibromyalgia: a randomized, double-blind, placebo-controlled, crossover study. Pain Rep 2023; 8:e1080. [PMID: 38226027 PMCID: PMC10789452 DOI: 10.1097/pr9.0000000000001080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 01/26/2023] [Accepted: 04/15/2023] [Indexed: 01/17/2024] Open
Abstract
Introduction Fibromyalgia (FM) is a chronic fluctuating, nociplastic pain condition. Naltrexone is a µ-opioid-receptor antagonist; preliminary studies have indicated a pain-relieving effect of low-dose naltrexone (LDN) in patients with FM. The impetus for studying LDN is the assumption of analgesic efficacy and thus reduction of adverse effects seen from conventional pharmacotherapy. Objectives First, to examine if LDN is associated with analgesic efficacy compared with control in the treatment of patients with FM. Second, to ascertain the analgesic efficacy of LDN in an experimental pain model in patients with FM evaluating the competence of the descending inhibitory pathways compared with controls. Third, to examine the pharmacokinetics of LDN. Methods The study used a randomized, double-blind, placebo-controlled, crossover design and had a 3-phase setup. The first phase included baseline assessment and a treatment period (days -3 to 21), the second phase a washout period (days 22-32), and the third phase a baseline assessment followed by a treatment period (days 33-56). Treatment was with either LDN 4.5 mg or an inactive placebo given orally once daily. The primary outcomes were Fibromyalgia Impact Questionnaire revised (FIQR) scores and summed pain intensity ratings (SPIR). Results Fifty-eight patients with FM were randomized. The median difference (IQR) for FIQR scores between LDN and placebo treatment was -1.65 (18.55; effect size = 0.15; P = 0.3). The median difference for SPIR scores was -0.33 (6.33; effect size = 0.13; P = 0.4). Conclusion Outcome data did not indicate any clinically relevant analgesic efficacy of the LDN treatment in patients with FM.
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Affiliation(s)
- Kirsten Bested
- Multidisciplinary Pain Clinic, Friklinikken, Grindsted, Denmark
| | - Lotte M. Jensen
- Multidisciplinary Pain Clinic, Friklinikken, Grindsted, Denmark
| | - Trine Andresen
- Molecular Diagnostics and Clinical Research Unit, Hospital Sonderjylland, Aabendraa, Denmark
| | - Grete Tarp
- Multidisciplinary Pain Clinic, Friklinikken, Grindsted, Denmark
| | - Louise Skovbjerg
- Multidisciplinary Pain Center, Neuroscience Center, Rigshospitalet, Copenhagen University Hospitals, Copenhagen, Denmark
| | | | - Anne V. Schmedes
- Department of Clinical Biochemistry and Immunology, Lillebaelt Hospital, University Hospital of Southern Denmark, Vejle, Denmark
| | - Ida K. Storgaard
- Department of Drug Design and Pharmacology, Copenhagen University Hospitals, Copenhagen, Denmark
| | - Jonna S. Madsen
- Department of Clinical Biochemistry and Immunology, Lillebaelt Hospital, University Hospital of Southern Denmark, Vejle, Denmark
- Department of Regional Health Research, University of Southern Denmark, Odense, Denmark
| | - Mads U. Werner
- Multidisciplinary Pain Center, Neuroscience Center, Rigshospitalet, Copenhagen University Hospitals, Copenhagen, Denmark
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Schmidt MG, Torres IL, Stahnke DN, Paniz VMV. [Low-dose naltrexone (LDN): consumption trend in Brazilian capitals and the Federal District, 2014-2020]. CIENCIA & SAUDE COLETIVA 2023; 28:947-955. [PMID: 36888876 DOI: 10.1590/1413-81232023283.10392022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 06/16/2022] [Indexed: 03/08/2023] Open
Abstract
The scope of this paper is an ecological study to determine the consumption of low-dose naltrexone (LDN) in the 26 Brazilian capitals and the Federal District and monitor the trend between the years 2014 to 2020. Data collection on the dispensation of manipulated naltrexone was done through the National Management System of Controlled Products, published in 2020, considering low-dose prescriptions of up to 5 mg. The calculation of the dispensation coefficients used the population estimates of the Brazilian Institute of Geography and Statistics. Descriptive statistical analysis and generalized Prais-Winsten regression analysis were used for the time series analysis. The trends observed were classified as increasing, stable, or decreasing, with a 95% confidence interval and 5% significance level. The results showed higher LDN consumption coefficients in the Mid-West, South and Southeast regions and lower coefficients in the North and Northeast. Increasing dispensation of LDN was observed in 55.6% of the capitals, being stationary in 44.4%, with no decreasing coefficients. Despite the limited evidence regarding LDN pharmacotherapy and its off-label prescription, the data show that prescription, dispensing, and consumption have been on the increase in Brazil, with emphasis on the central-south regions of the country.
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Affiliation(s)
- Michele Gabriela Schmidt
- Programa de Pós-Graduação em Saúde Coletiva, Universidade do Vale do Rio dos Sinos. Av. Unisinos 950, Cristo Rei. 93022-750 São Leopoldo RS Brasil.
| | - Iraci Ls Torres
- Laboratório de Farmacologia e Neuromodulação da Dor: Investigação Pré-Clínica, Hospital de Clínicas de Porto Alegre, Faculdade de Medicina, Universidade Federal do Rio Grande do Sul. Porto Alegre RS Brasil
| | - Douglas Nunes Stahnke
- Programa de Pós-Graduação em Saúde Coletiva, Universidade do Vale do Rio dos Sinos. Av. Unisinos 950, Cristo Rei. 93022-750 São Leopoldo RS Brasil.
| | - Vera Maria Vieira Paniz
- Programa de Pós-Graduação em Saúde Coletiva, Universidade do Vale do Rio dos Sinos. Av. Unisinos 950, Cristo Rei. 93022-750 São Leopoldo RS Brasil.
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Raknes G, Småbrekke L. No change in the consumption of thyroid hormones after starting low dose naltrexone (LDN): a quasi-experimental before-after study. BMC Endocr Disord 2020; 20:151. [PMID: 33004044 PMCID: PMC7528597 DOI: 10.1186/s12902-020-00630-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 09/24/2020] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Low dose naltrexone (LDN) is reported to have beneficial effects in several autoimmune diseases. The purpose of this study was to examine whether starting LDN was followed by changes in the dispensing of thyroid hormones to patients with hypothyroidism. METHODS We performed a quasi-experimental before-after study based on the Norwegian Prescription Database. Study participants were identified by using reimbursement codes for hypothyroidism. Cumulative dispensed Defined Daily Doses and the number of users of triiodothyronine (T3) and levothyroxine (LT4) 1 year before and after the first LDN prescription was compared in three groups based on LDN exposure. RESULTS We identified 898 patients that met the inclusion criteria. There was no association between starting LDN and the subsequent dispensing of thyroid hormones. If anything, there was a tendency towards increasing LT4 consumption with increasing LDN exposure. CONCLUSION The results of this study do not support claims of efficacy of LDN in hypothyroidism.
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Affiliation(s)
- Guttorm Raknes
- Regional Medicines Information and Pharmacovigilance Centre (RELIS), University Hospital of North Norway, Tromsø, Norway
- Raknes Research, Ulset, Norway
| | - Lars Småbrekke
- Department of Pharmacy, Faculty of Health Sciences, UiT - The arctic university of Norway, Tromsø, Norway.
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Bruun-Plesner K, Blichfeldt-Eckhardt MR, Vaegter HB, Lauridsen JT, Amris K, Toft P. Low-Dose Naltrexone for the Treatment of Fibromyalgia: Investigation of Dose–Response Relationships. PAIN MEDICINE 2020; 21:2253-2261. [DOI: 10.1093/pm/pnaa001] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abstract
Objective
This study explores dose–response relationships when treating fibromyalgia with low-dose naltrexone.
Design
A single-blinded clinical trial was carried out using the “up-and-down” method.
Subjects
Subjects included women with a diagnosis of fibromyalgia aged 18–60 years who had been referred to treatment at a public pain clinic at a Danish university hospital.
Methods
The test doses were in the range 0.75–6 mg, and the dosing interval was 0.75 mg. The method was sequential and allowed predicting the dose effective in 50% (ED50) and 95% (ED95) of the subjects when the dose had shifted direction 10 times, and six pairs of “up-and-down” data were available.
Results
A total of 27 subjects were included in the study; two subjects were withdrawn. After inclusion of 25 evaluable subjects, the dose estimates were calculated as 3.88 mg for ED50 and 5.40 mg for ED95. As a secondary outcome, the effects on 10 common fibromyalgia symptoms were evaluated. A high interindividual variation was observed both in the symptom presentation at baseline and in which symptoms were reduced by low-dose naltrexone.
Conclusions
This study is the first to explore dose–response relationships in the treatment of fibromyalgia with low-dose naltrexone. Future placebo-controlled randomized clinical trials are needed, and according to our findings, 4.5 mg, which has previously been used, seems to be a relevant test dose. We recommend that future studies include additional nonpain fibromyalgia symptoms as outcome measures.
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Affiliation(s)
- Karin Bruun-Plesner
- Pain Research Group, Pain Centre, Odense University Hospital, Odense, Denmark
- Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
- Open Patient Data Explorative Network (OPEN), Odense University Hospital, Odense, Denmark
| | - Morten Rune Blichfeldt-Eckhardt
- Pain Research Group, Pain Centre, Odense University Hospital, Odense, Denmark
- Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
| | - Henrik Bjarke Vaegter
- Pain Research Group, Pain Centre, Odense University Hospital, Odense, Denmark
- Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
| | - Joergen T Lauridsen
- Department of Business and Economics, University of Southern Denmark, Odense, Denmark
| | - Kirstine Amris
- Department of Rheumatology, The Parker Institute, Copenhagen University Hospital, Bispebjerg-Frederiksberg, Denmark
| | - Palle Toft
- Department of Anesthesiology and Intensive Care, Odense University Hospital, Odense, Denmark
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7
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Chande N, Costello SP, Limketkai BN, Parker CE, Nguyen TM, Macdonald JK, Feagan BG. Alternative and Complementary Approaches for the Treatment of Inflammatory Bowel Disease: Evidence From Cochrane Reviews. Inflamm Bowel Dis 2020; 26:843-851. [PMID: 31560744 DOI: 10.1093/ibd/izz223] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Indexed: 12/12/2022]
Abstract
The Cochrane IBD Group presented a symposium at Digestive Diseases Week 2018 entitled “Alternative and Complementary Approaches for the Treatment of IBD: Evidence from Cochrane Reviews.” This article summarizes the data presented at this symposium.
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Affiliation(s)
- Nilesh Chande
- Division of Gastroenterology, Department of Medicine, University of Western Ontario, London, Ontario, Canada.,Cochrane IBD Group, University of Western Ontario, London, Ontario, Canada
| | - Samuel P Costello
- Department of Gastroenterology, The Queen Elizabeth Hospital, Adelaide, Australia
| | - Berkeley N Limketkai
- Division of Digestive Diseases, UCLA School of Medicine, Los Angeles, California, USA
| | | | - Tran M Nguyen
- Robarts Clinical Trials Inc. London, Ontario, Canada
| | - John K Macdonald
- Division of Gastroenterology, Department of Medicine, University of Western Ontario, London, Ontario, Canada.,Cochrane IBD Group, University of Western Ontario, London, Ontario, Canada
| | - Brian G Feagan
- Division of Gastroenterology, Department of Medicine, University of Western Ontario, London, Ontario, Canada.,Cochrane IBD Group, University of Western Ontario, London, Ontario, Canada.,Department of Epidemiology and Biostatistics, University of Western Ontario, London, Ontario, Canada
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Abstract
This paper is the fortieth consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2017 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, CUNY, 65-30 Kissena Blvd., Flushing, NY, 11367, United States.
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9
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Changes in the consumption of antiepileptics and psychotropic medicines after starting low dose naltrexone: A nation-wide register-based controlled before-after study. Sci Rep 2019; 9:15085. [PMID: 31636347 PMCID: PMC6803623 DOI: 10.1038/s41598-019-51569-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 10/03/2019] [Indexed: 01/03/2023] Open
Abstract
In this controlled before-after study based on data from the Norwegian Prescription Database, we examine whether starting off-label use of Low Dose Naltrexone (LDN) is followed by changes in the consumption of psychotropic medicines including antiepileptics. Patients that collected LDN for the first time in 2013 (N = 11247) were included and stratified into three groups based on LDN exposure. We compared differences in means of cumulative number of defined daily doses (DDD) as well as changes in the number of users one year before and one year after starting LDN. There was a dose-response association between increasing LDN exposure and reductions in the number of users of antiepileptics, antipsychotics and antidepressants. There were significant difference-in-differences in DDDs between the groups with the lowest and highest LDN exposure of antipsychotics (1.4 DDD, 95% CI 0.4 to 2.3, p = 0.007), and in number of users of antiepileptics (3.1% points, 95% CI 1.6% to 4.6%, p < 0.001), antipsychotics (2.1% points, 95% CI 1.2% to 3%, p < 0.001), and antidepressants (2.8% points, 95% CI 1.1% to 4.4%, p = 0.001). The findings show an association between the initiation of persistent LDN use and reduced consumption of several psychotropic medicines and antiepileptics. Beneficial effects of LDN in the treatment of psychiatric diseases cannot be ruled out.
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10
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Trofimovitch D, Baumrucker SJ. Pharmacology Update: Low-Dose Naltrexone as a Possible Nonopioid Modality for Some Chronic, Nonmalignant Pain Syndromes. Am J Hosp Palliat Care 2019; 36:907-912. [PMID: 30917675 DOI: 10.1177/1049909119838974] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Pain can have a devastating effect on the quality of life of patients in palliative medicine. Thus far, majority of research has been centered on opioid-based pain management, with a limited empirical evidence for the use of nonopioid medications in palliative care. However, opioid and nonopioid medications such as nonsteroidal anti-inflammatory drugs have their limitations in the clinical use due to risk of adverse effects, therefore, there is a need for more research to be directed to finding an alternative approach to pain management in comfort care setting. The purpose of this article is to discuss a potential new drug that would adequately alleviate pain and enhance quality of life without significant risks of adverse effects that would limit its use. Naltrexone is a reversible competitive antagonist at μ-opioid and κ-opioid receptors, which when used at standard doses of 50 to 150 mg was initially intended for use in opioid and alcohol use disorders. However, it was discovered that its use in low doses follows alternate pharmacodynamic pathways with various effects. When used in doses of 1 to 5 mg it acts as a glial modulator with a neuroprotective effect via inhibition of microglial activation. It binds to Toll-like receptor 4 and acts as an antagonist, therefore inhibiting the downstream cellular signaling pathways that ultimately lead to pro-inflammatory cytokines, therefore reducing inflammatory response. Its other mode of action involves transient opioid receptor blockade ensuing from low-dose use which upregulates opioid signaling resulting in increased levels of endogenous opioid production, known as opioid rebound effect. Low dose naltrexone has gained popularity as an off-label treatment of several autoimmune diseases including multiple sclerosis and inflammatory bowel disease, as well as chronic pain disorders including fibromyalgia, complex regional pain syndrome, and diabetic neuropathy. Low-dose naltrexone (LDN) may also have utility in improving mood disorders and the potential to enhance the quality of life. This article will therefore propose the potential off-label use of LDN in management of nonmalignant pain in the palliative medicine setting.
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Affiliation(s)
- Diana Trofimovitch
- 1 Department of Internal Medicine, East Tennessee State University James H Quillen College of Medicine, Johnson City, TN, USA
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11
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Effect of Naltrexone Hydrochloride on Cytochrome P450 1A2, 2C9, 2D6, and 3A4 Activity in Human Liver Microsomes. Eur J Drug Metab Pharmacokinet 2019; 43:707-713. [PMID: 29744741 DOI: 10.1007/s13318-018-0482-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND OBJECTIVE Cytochrome P450 (CYP) 1A2, 2C9, 2D6, and 3A4 are the most important phase I drug-metabolizing enzymes in the liver, but there is a dearth of literature available on the effects of naltrexone hydrochloride on these major enzymes present in the human liver. Thus, in the present study, the effect of naltrexone hydrochloride on the activity of CYP1A2, 2C9, 2D6, and 3A4 using human liver microsomes (HLM) was investigated. METHODS A selective probe for CYP1A2, 2C9, 2D6, and 3A4 was incubated with HLM with or without naltrexone hydrochloride. Phenacetin O-deethylation, tolbutamide 4-hydroxylation, dextromethorphan O-demethylation, and testosterone 6β-hydroxylation reactions were monitored for enzyme activity. RESULTS The activity of all the studied CYP enzymes except 1A2 was significantly inhibited by naltrexone hydrochloride 1 µM. Furthermore, 1 µM naltrexone hydrochloride inhibited CYP3A4 enzyme activity, the most by 37.9% followed by CYP2C9 (36.5%) and CYP2D6 (31.8%). The CYP2C9 and CYP2D6 metabolic activities were greatly affected by naltrexone hydrochloride, which even at the lowest concentration of naltrexone hydrochloride (0.01 µM) significantly decreased the metabolic activity by 34.9 and 16.0%, respectively. The half maximal inhibition concentration (IC50) values for CYP2C9 and CYP2D6 inhibition were 3.40 ± 1.78 and 5.92 ± 1.58 µM, respectively. CONCLUSION These outcomes advocate that there is a great possibility of drug interactions resulting from the concurrent administration of naltrexone hydrochloride with actives that are metabolized by these CYP enzymes, particularly CYP2C9 and CYP2D6. Nevertheless, further clarification is needed through detailed in vivo pharmacokinetic studies.
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12
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Sikora M, Rakowska A, Olszewska M, Rudnicka L. The Use of Naltrexone in Dermatology. Current Evidence and Future Directions. Curr Drug Targets 2019; 20:1058-1067. [PMID: 30887922 DOI: 10.2174/1389450120666190318121122] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 03/04/2019] [Accepted: 03/10/2019] [Indexed: 01/29/2023]
Abstract
Naltrexone is a competitive opioid receptor antagonist approved as supportive treatment in alcohol dependence and opioid addiction. At a dose of 50-100 mg daily, naltrexone is used off-label in dermatology for the treatment of trichotillomania and different types of pruritus. At a dose as low as 1- 5 mg per day, naltrexone demonstrates immunomodulatory action i.e. modulates Toll-like receptors signaling, decreases release of proinflammatory cytokines (tumor necrosis factor, interleukin-6, interleukin- 12), inhibits T lymphocyte proliferation, down-regulates the expression of chemokine receptors and adhesion molecules. The efficacy of standard and low doses of naltrexone in a variety of dermatological disorders has been reported. These include diseases such as familial benign chronic pemphigus (Hailey-Hailey disease), dermatomyositis, systemic sclerosis, psoriasis and lichen planopilaris. Optimistic preliminary findings, low cost of therapy and good tolerance make naltrexone a promising alternative therapy or adjunct drug in dermatology.
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Affiliation(s)
- Mariusz Sikora
- Department of Dermatology, Medical University of Warsaw, Koszykowa 82A, 02-008 Warsaw, Poland
| | - Adriana Rakowska
- Department of Dermatology, Medical University of Warsaw, Koszykowa 82A, 02-008 Warsaw, Poland
| | - Małgorzata Olszewska
- Department of Dermatology, Medical University of Warsaw, Koszykowa 82A, 02-008 Warsaw, Poland
| | - Lidia Rudnicka
- Department of Dermatology, Medical University of Warsaw, Koszykowa 82A, 02-008 Warsaw, Poland
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13
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Low dose naltrexone: Effects on medication in rheumatoid and seropositive arthritis. A nationwide register-based controlled quasi-experimental before-after study. PLoS One 2019; 14:e0212460. [PMID: 30763385 PMCID: PMC6375629 DOI: 10.1371/journal.pone.0212460] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 02/01/2019] [Indexed: 11/19/2022] Open
Abstract
In recent years, low dose naltrexone (LDN) has been used as an off-label therapy for several chronic diseases. Results from small laboratory and clinical studies indicate some beneficial effects of LDN in autoimmune diseases, but clinical research on LDN in rheumatic disease is limited. Using a pharmacoepidemiological approach, we wanted to test the hypothesis that starting LDN leads to reduced dispensing of medicines used in the treatment of rheumatic disease. We performed a controlled before-after study based on the Norwegian Prescription Database (NorPD) to compare prescriptions to patients one year before and one year after starting LDN in 2013. The identified patients (n = 360) were stratified into three groups based on LDN exposure. Outcomes were differences in dispensing of medicines used in rheumatic disease. In persistent LDN users, there was a 13% relative reduction in cumulative defined daily doses (DDD) of all medicines examined corresponding to -73.3 DDD per patient (95% CI -120,2 to -26.4, p = 0.003), and 23% reduction of analgesics (-21.6 DDD (95% CI -35.5 to -7.6, p<0.009)). There was no significant DDD change in patients with lower LDN exposure. Persistent LDN users had significantly reduced DDDs of NSAID and opioids, and a lower proportion of users of DMARDs (-6.7 percentage points, 95% CI -12.3 to-1.0, p = 0.028), TNF-α antagonists and opioids. There was a decrease in the number of NSAID users among patients with the least LDN exposure. Important limitations are that prescription data are proxies for clinical effects and that a control group unexposed to LDN is lacking. The results support the hypothesis that persistent use of LDN reduces the need for medication used in the treatment of rheumatic and seropositive arthritis. Randomised clinical trials on LDN in rheumatic disease are warranted.
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Bolton M, Hodkinson A, Boda S, Mould A, Panagioti M, Rhodes S, Riste L, van Marwijk H. Serious adverse events reported in placebo randomised controlled trials of oral naltrexone: a systematic review and meta-analysis. BMC Med 2019; 17:10. [PMID: 30642329 PMCID: PMC6332608 DOI: 10.1186/s12916-018-1242-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 12/17/2018] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Naltrexone is an opioid antagonist used in many different conditions, both licensed and unlicensed. It is used at widely varying doses from 3 to 250 mg. The aim of this review was to extensively evaluate the safety of oral naltrexone by examining the risk of serious adverse events and adverse events in randomised controlled trials of naltrexone compared to placebo. METHODS A systematic search of the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, other databases and clinical trials registries was undertaken up to May 2018. Parallel placebo-controlled randomised controlled trials longer than 4 weeks published after 1 January 2001 of oral naltrexone at any dose were selected. Any condition or age group was included, excluding only studies in opioid or ex-opioid users owing to possible opioid/opioid antagonist interactions. The systematic review used the guidance of the Cochrane Handbook and Preferred Reporting Items for Systematic Reviews and Meta-analyses harms checklist throughout. Numerical data were independently extracted by two people and cross-checked. Risk of bias was assessed with the Cochrane risk-of-bias tool. Meta-analyses were performed in R using random effects models throughout. RESULTS Eighty-nine randomised controlled trials with 11,194 participants were found, studying alcohol use disorders (n = 38), various psychiatric disorders (n = 13), impulse control disorders (n = 9), other addictions including smoking (n = 18), obesity or eating disorders (n = 6), Crohn's disease (n = 2), fibromyalgia (n = 1) and cancers (n = 2). Twenty-six studies (4,960 participants) recorded serious adverse events occurring by arm of study. There was no evidence of increased risk of serious adverse events for naltrexone compared to placebo (risk ratio 0.84, 95% confidence interval 0.66-1.06). Sensitivity analyses pooling risk differences supported this conclusion (risk difference -0.01, 95% confidence interval -0.02-0.00) and subgroup analyses showed that results were consistent across different doses and disease groups. Secondary analysis revealed only six marginally significant adverse events for naltrexone compared to placebo, which were of mild severity. CONCLUSIONS Naltrexone does not appear to increase the risk of serious adverse events over placebo. These findings confirm the safety of oral naltrexone when used in licensed indications and encourage investments to undertake efficacy studies in unlicensed indications. TRIAL REGISTRATION PROSPERO 2017 CRD42017054421 .
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Affiliation(s)
- Monica Bolton
- School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9PL, UK
| | - Alex Hodkinson
- Centre for Primary Care, Division of Population Health, Health Services Research & Primary Care, Williamson Building, Oxford Road, Manchester, M13 9PL, UK.
| | - Shivani Boda
- School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9PL, UK
| | - Alan Mould
- Centre for Primary Care, Division of Population Health, Health Services Research & Primary Care, Williamson Building, Oxford Road, Manchester, M13 9PL, UK
| | - Maria Panagioti
- NIHR School for Primary Care Research, NIHR Greater Manchester Primary Care Patient Safety Translational Research Centre, Manchester Academic Health Science Centre, University of Manchester, Brighton, M13 9PL, UK
| | - Sarah Rhodes
- Centre for Biostatistics, Division of Population Health, Health Services Research and Primary Care, School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9PL, UK
| | - Lisa Riste
- Division of Population Health, Health Services Research and Primary Care, School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9PL, UK
| | - Harm van Marwijk
- Division of Population Health, Health Services Research and Primary Care, School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9PL, UK
- Brighton and Sussex Medical School, Watson Building, University of Brighton, Brighton, BN1 9PH, UK
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Zagon IS, McLaughlin PJ. Intermittent blockade of OGFr and treatment of autoimmune disorders. Exp Biol Med (Maywood) 2018; 243:1323-1330. [PMID: 30541348 PMCID: PMC6348594 DOI: 10.1177/1535370218817746] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
IMPACT STATEMENT This mini-review presents information on the intermittent blockade of the opioid growth factor (OGF)-OGF receptor (OGFr) axis by low-dose naltrexone (LDN), and the role of enkephalin (i.e. OGF) in autoimmune disorders, specifically multiple sclerosis, Crohn's, and fibromyalgia. Clinical reports on subjects taking LDN have documented reduced fatigue, few side-effects, and improved overall health. Preclinical studies on mice with experimental autoimmune encephalomyelitis (EAE), the animal model of multiple sclerosis, revealed that immunization for EAE reduces serum OGF. Intermittent OGFr blockade with LDN restores serum enkephalin levels that correlate with reduced behavioral and pathological signs of EAE; LDN also increases enkephalin levels in naïve mice. The interplay between LDN, and the onset and treatment of autoimmune diseases, chronic pain, and other addictive behaviors requires further investigation, but highlights a central role for enkephalins and intermittent blockade of the OGF-OGFr pathway in pathogenesis and treatment of these disorders.
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Affiliation(s)
- Ian S Zagon
- Department of Neural & Behavioral Sciences, Penn
State University College of Medicine, Hershey, PA 17033, USA
| | - Patricia J McLaughlin
- Department of Neural & Behavioral Sciences, Penn
State University College of Medicine, Hershey, PA 17033, USA
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Toljan K, Vrooman B. Low-Dose Naltrexone (LDN)-Review of Therapeutic Utilization. Med Sci (Basel) 2018; 6:medsci6040082. [PMID: 30248938 PMCID: PMC6313374 DOI: 10.3390/medsci6040082] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Revised: 09/16/2018] [Accepted: 09/18/2018] [Indexed: 02/07/2023] Open
Abstract
Naltrexone and naloxone are classical opioid antagonists. In substantially lower than standard doses, they exert different pharmacodynamics. Low-dose naltrexone (LDN), considered in a daily dose of 1 to 5 mg, has been shown to reduce glial inflammatory response by modulating Toll-like receptor 4 signaling in addition to systemically upregulating endogenous opioid signaling by transient opioid-receptor blockade. Clinical reports of LDN have demonstrated possible benefits in diseases such as fibromyalgia, Crohn’s disease, multiple sclerosis, complex-regional pain syndrome, Hailey-Hailey disease, and cancer. In a dosing range at less than 1 μg per day, oral naltrexone or intravenous naloxone potentiate opioid analgesia by acting on filamin A, a scaffolding protein involved in μ-opioid receptor signaling. This dose is termed ultra low-dose naltrexone/naloxone (ULDN). It has been of use in postoperative control of analgesia by reducing the need for the total amount of opioids following surgery, as well as ameliorating certain side-effects of opioid-related treatment. A dosing range between 1 μg and 1 mg comprises very low-dose naltrexone (VLDN), which has primarily been used as an experimental adjunct treatment for boosting tolerability of opioid-weaning methadone taper. In general, all of the low-dose features regarding naltrexone and naloxone have been only recently and still scarcely scientifically evaluated. This review aims to present an overview of the current knowledge on these topics and summarize the key findings published in peer-review sources. The existing potential of LDN, VLDN, and ULDN for various areas of biomedicine has still not been thoroughly and comprehensively addressed.
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Affiliation(s)
- Karlo Toljan
- Department of Pathophysiology, University of Zagreb School of Medicine, Kispaticeva 12, 10 000 Zagreb, Croatia.
| | - Bruce Vrooman
- Section of Pain Medicine, Department of Anesthesiology, Dartmouth-Hitchcock Medical Center, 1 Medical Center Dr, Lebanon, NH 03756, USA.
- Department of Anesthesiology, Geisel School of Medicine at Dartmouth, Hanover, NH 03756, USA.
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18
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Li Z, You Y, Griffin N, Feng J, Shan F. Low-dose naltrexone (LDN): A promising treatment in immune-related diseases and cancer therapy. Int Immunopharmacol 2018; 61:178-184. [DOI: 10.1016/j.intimp.2018.05.020] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 05/22/2018] [Accepted: 05/22/2018] [Indexed: 12/16/2022]
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Raknes G, Simonsen P, Småbrekke L. The Effect of Low-Dose Naltrexone on Medication in Inflammatory Bowel Disease: A Quasi Experimental Before-and-After Prescription Database Study. J Crohns Colitis 2018; 12:677-686. [PMID: 29385430 PMCID: PMC5972567 DOI: 10.1093/ecco-jcc/jjy008] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 01/17/2018] [Indexed: 12/23/2022]
Abstract
BACKGROUND AND AIMS Low-dose naltrexone [LDN] is a controversial off-label treatment used by many Crohn's disease [CD] and ulcerative colitis [UC] patients. A small number of preliminary studies indicate that LDN might be beneficial in CD, but evidence is too scarce to demonstrate efficacy. We sought to examine whether initiation of LDN therapy by patients with inflammatory bowel disease [IBD] was followed by changes in dispensing of relevant medication. METHODS We performed a quasi-experimental before-and-after study following a sudden increase in LDN use in the Norwegian population in 2013. IBD patients were identified from among all the patients who had at least one LDN prescription recorded in the Norwegian Prescription Database [NorPD] in 2013. Drug dispensing 2 years before and after the first LDN prescription was compared. RESULTS We identified 582 IBD patients who had received LDN. Of the 256 patients who became persistent LDN users, there were reductions in the number of users for [i] all examined drugs [-12%], [ii] intestinal anti-inflammatory agents [-17%], [iii] other immunosuppressants [-29%], [iv] intestinal corticosteroids [-32%] and [v] aminosalicylates [-17%]. In subgroups of identified CD and UC patients, there were significant reductions in the number of users of intestinal corticosteroids [CD: -44%, UC: -53%] and systemic corticosteroids [UC: -24%]. No significant differences in cumulative defined daily doses were observed. CONCLUSIONS Our findings imply that the initiation of LDN in IBD is followed by reduced dispensing of several drugs considered essential in the treatment of CD and UC.
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Affiliation(s)
- Guttorm Raknes
- Regional Medicines Information and Pharmacovigilance Centre [RELIS], University Hospital of North Norway, Tromsø, Norway,Raknes Research, Ulset, Norway,Corresponding author: Guttorm Raknes, RELIS, Box 79, 9038 Tromsø, Norway. E-mail:
| | | | - Lars Småbrekke
- Department of Pharmacy, Faculty of Health Sciences, UiT – The Arctic University of Norway, Tromsø, Norway
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Patten DK, Schultz BG, Berlau DJ. The Safety and Efficacy of Low-Dose Naltrexone in the Management of Chronic Pain and Inflammation in Multiple Sclerosis, Fibromyalgia, Crohn's Disease, and Other Chronic Pain Disorders. Pharmacotherapy 2018; 38:382-389. [DOI: 10.1002/phar.2086] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Ludwig MD, Zagon IS, McLaughlin PJ. Featured Article: Modulation of the OGF-OGFr pathway alters cytokine profiles in experimental autoimmune encephalomyelitis and multiple sclerosis. Exp Biol Med (Maywood) 2018; 243:361-369. [PMID: 29307283 DOI: 10.1177/1535370217749830] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The endogenous neuropeptide opioid growth factor, chemically termed [Met5]-enkephalin, has growth inhibitory and immunomodulatory properties. Opioid growth factor is distributed widely throughout most tissues, is autocrine and paracrine produced, and interacts at the nuclear-associated receptor, OGFr. Serum levels of opioid growth factor are decreased in patients with multiple sclerosis and in animals with experimental autoimmune encephalomyelitis suggesting that the OGF-OGFr pathway becomes dysregulated in this disease. This study begins to assess other cytokines that are altered following opioid growth factor or low-dose naltrexone modulation of the OGF-OGFr axis in mice with experimental autoimmune encephalomyelitis using serum samples collected in mice treated for 10 or 20 days and assayed by a multiplex cytokine assay for inflammatory markers. Cytokines of interest were validated in mice at six days following immunization for experimental autoimmune encephalomyelitis. In addition, selected cytokines were validated with serum from MS patients treated with low-dose naltrexone alone or low-dose naltrexone in combination with glatiramer acetate (Copaxone®). Experimental autoimmune encephalomyelitis mice had elevated levels of 7 of 10 cytokines. Treatment with opioid growth factor or low-dose naltrexone resulted in elevated expression levels of the IL-6 cytokine, and significantly reduced IL-10 values, relative to saline-treated experimental autoimmune encephalomyelitis mice. TNF-γ values were increased in experimental autoimmune encephalomyelitis mice relative to normal, but were not altered by opioid growth factor or low-dose naltrexone. IFN-γ levels were reduced in opioid growth factor- or low-dose naltrexone-treated experimental autoimmune encephalomyelitis mice relative to saline-treated mice at 10 days, and elevated relative to normal values at 20 days. Validation studies revealed that within six days of immunization, opioid growth factor or low-dose naltrexone modulated IL-6 and IL-10 cytokine expression. Validation in human serum revealed markedly reduced IL-6 cytokine levels in MS patients taking low-dose naltrexone relative to standard care. In summary, modulation of the OGF-OGFr pathway regulates some inflammatory cytokines, and together with opioid growth factor serum levels, may begin to form a panel of valid biomarkers to monitor progression of multiple sclerosis and response to therapy. Impact statement Modulation of the opioid growth factor (OGF)-OGF receptor (OGFr) alters inflammatory cytokine expression in multiple sclerosis and experimental autoimmune encephalomyelitis (EAE). Multiplex cytokine assays demonstrated that mice with chronic EAE and treated with either OGF or low-dose naltrexone (LDN) had decreased expression of interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), and the anti-inflammatory cytokine IL-10 within 10 days or treatment, as well as increased serum expression of the pro-inflammatory cytokine IL-6, relative to immunized mice receiving saline. Multiplex data were validated using ELISA kits and serum from MS patients treated with LDN and revealed decreased in IL-6 levels in patients taking LDN relative to standard care alone. These data, along with serum levels of OGF, begin to formulate a selective biomarker profile for MS that is easily measured and effective at monitoring disease progression and response to therapy.
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Affiliation(s)
- Michael D Ludwig
- Department of Neural and Behavioral Sciences, College of Medicine, Pennsylvania State University, PA 17033, USA
| | - Ian S Zagon
- Department of Neural and Behavioral Sciences, College of Medicine, Pennsylvania State University, PA 17033, USA
| | - Patricia J McLaughlin
- Department of Neural and Behavioral Sciences, College of Medicine, Pennsylvania State University, PA 17033, USA
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Raknes G, Småbrekke L. Low dose naltrexone in multiple sclerosis: Effects on medication use. A quasi-experimental study. PLoS One 2017; 12:e0187423. [PMID: 29099849 PMCID: PMC5669439 DOI: 10.1371/journal.pone.0187423] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 10/19/2017] [Indexed: 11/18/2022] Open
Abstract
Low dose naltrexone (LDN) has become a popular off-label therapy for multiple sclerosis (MS). A few small, randomized studies indicate that LDN may have beneficial effects in MS and other autoimmune diseases. If proven efficacious, it would be a cheap and safe alternative to the expensive treatments currently recommended for MS. We investigated whether a sudden increase in LDN use in Norway in 2013 was followed by changes in dispensing of other medications used to treat MS. We performed a quasi-experimental before–and–after study based on population data from the Norwegian Prescription Database (NorPD). We included all patients that collected at least one LDN prescription in 2013, and had collected at least two medications with a reimbursement code for MS, or collected a medication with MS as the only indication in 2009 or 2010. Outcomes were differences in cumulative dispensed doses and incidence of users of disease modifying MS therapies, and medications used to treat MS symptoms two years before and two years after dispensing the initial LDN prescription. The eligible 341 patients collected 20 921 prescriptions in the observation period. Apart from changes in line with general trends in MS therapy in Norway, there was no difference in neither dispensed cumulative doses or number of prevalent users of MS specific medication. Initiation of LDN was not followed by reductions of other medications used to treat symptoms associated with MS.
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Affiliation(s)
- Guttorm Raknes
- Regional Medicines Information and Pharmacovigilance Centre (RELIS), University Hospital of North Norway, Tromsø, Norway
- Raknes Research, Ulset, Norway
- * E-mail:
| | - Lars Småbrekke
- Department of Pharmacy, Faculty of Health Sciences, UiT—The Arctic University of Norway, Tromsø, Norway
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Ludwig MD, Zagon IS, McLaughlin PJ. Featured Article: Serum [Met 5]-enkephalin levels are reduced in multiple sclerosis and restored by low-dose naltrexone. Exp Biol Med (Maywood) 2017; 242:1524-1533. [PMID: 28766982 PMCID: PMC5648293 DOI: 10.1177/1535370217724791] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 07/14/2017] [Indexed: 11/15/2022] Open
Abstract
Low-dose naltrexone is a widely used off-label therapeutic prescribed for a variety of immune-related disorders. The mechanism underlying low-dose naltrexone's efficacy for fatigue, Crohn's disease, fibromyalgia, and multiple sclerosis is, in part, intermittent blockade of opioid receptors followed by upregulation of endogenous opioids. Short, intermittent blockade by naltrexone specifically blocks the opioid growth factor receptor resulting in biofeedback events that increase production of the endogenous opioid growth factor (OGF) (chemically termed [Met5]-enkephalin) facilitating interactions between opioid growth factor and opioid growth factor receptor that ultimately, result in inhibited cell proliferation. Preclinical studies have reported that enkephalin levels are deficient in animal models of experimental autoimmune encephalomyelitis, a mouse model of multiple sclerosis. Our hypothesis is that serum enkephalin levels are diminished in humans with multiple sclerosis and experimental autoimmune encephalomyelitis mice, and that change in serum opioid growth factor levels may serve as a reasonable candidate biomarker for the onset of experimental autoimmune encephalomyelitis and response to therapy. To address this, we designed a two-part study to measure endogenous opioids in multiple sclerosis patients, and to investigate the temporal pattern of decline in serum enkephalin concentrations in mice with chronic progressive experimental autoimmune encephalomyelitis and treated with low-dose naltrexone. For comparison, we investigated whether low-dose naltrexone exposure in normal mice also resulted in altered enkephalin levels. In both animal models, we monitored tactile and heat sensitivity, as well as differential white blood cell counts as indicators of inflammation. Serum [Met5]-enkephalin levels were lower in humans with multiple sclerosis relative to non-multiple sclerosis patients, and low-dose naltrexone restored their levels. In experimental autoimmune encephalomyelitis mice, [Met5]-enkephalin levels were depressed prior to the appearance of clinical disease, and were restored with low-dose naltrexone treatment. Low-dose naltrexone therapy had no effect on serum [Met5]-enkephalin or β-endorphin in normal mice. Thus, [Met5]-enkephalin (i.e. opioid growth factor) may be a reasonable candidate biomarker for multiple sclerosis, and may signal new pathways for treatment of autoimmune disorders. Impact statement This report presents human and animal data identifying a novel biomarker for the onset and progression of multiple sclerosis (MS). Humans diagnosed with MS have reduced serum levels of OGF (i.e. [Met5]-enkephalin) relative to non-MS neurologic patients, and low-dose naltrexone (LDN) therapy restored their enkephalin levels. Serum OGF levels were reduced in mice immunized with MOG35-55 prior to any clinical behavioral sign of experimental autoimmune encephalomyelitis, and LDN therapy restored their serum OGF levels. β-endorphin concentrations were not altered by LDN in humans or mice. Thus, blood levels of OGF may serve as a new, selective biomarker for the progression of MS, as well as response to therapy.
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Affiliation(s)
- Michael D Ludwig
- Department of Neural & Behavioral Sciences, College of Medicine, Pennsylvania State University, PA 17033, USA
| | - Ian S Zagon
- Department of Neural & Behavioral Sciences, College of Medicine, Pennsylvania State University, PA 17033, USA
| | - Patricia J McLaughlin
- Department of Neural & Behavioral Sciences, College of Medicine, Pennsylvania State University, PA 17033, USA
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Raknes G, Småbrekke L. Low-dose naltrexone and opioid consumption: a drug utilization cohort study based on data from the Norwegian prescription database. Pharmacoepidemiol Drug Saf 2017; 26:685-693. [PMID: 28370746 PMCID: PMC5485080 DOI: 10.1002/pds.4201] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 02/01/2017] [Accepted: 03/01/2017] [Indexed: 01/08/2023]
Abstract
PURPOSE Low-dose naltrexone (LDN) is used in a wide range of conditions, including chronic pain and fibromyalgia. Because of the opioid antagonism of naltrexone, LDN users are probably often warned against concomitant use with opioids. In this study, based on data from the Norwegian prescription database, we examine changes in opioid consumption after starting LDN therapy. METHODS We included all Norwegian patients (N = 3775) with at least one recorded LDN prescription in 2013 and at least one dispensed opioid prescription during the 365 days preceding the first LDN prescription. We allocated the patients into three subgroups depending on the number of collected LDN prescriptions and recorded the number of defined daily doses (DDDs) on collected prescriptions on opioids, nonsteroidal anti-inflammatory drugs and other analgesics and antipyretics from the same patients. RESULTS Among the patients collecting ≥4 LDN prescriptions, annual average opioid consumption was reduced by 41 DDDs per person (46%) compared with that of the previous year. The reduction was 12 DDDs per person (15%) among users collecting two to three prescriptions and no change among those collecting only one LDN prescription. We observed no increase in the number of DDDs in nonsteroidal anti-inflammatory drugs or other analgesics and antipyretics corresponding to the decrease in opioid use. CONCLUSIONS Possibly, LDN users avoided opioids because of warnings on concomitant use or the patients continuing on LDN were less opioid dependent than those terminating LDN. Therapeutic effects of LDN contributing to lower opioid consumption cannot be ruled out. © 2017 The Authors. Pharmacoepidemiology & Drug Safety Published by John Wiley & Sons Ltd.
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Affiliation(s)
- Guttorm Raknes
- Regional Medicines Information and Pharmacovigilance Centre (RELIS), University Hospital of North Norway, Tromsø, Norway.,National Centre for Emergency Primary Health Care, Uni Research Health, Bergen, Norway
| | - Lars Småbrekke
- Department of Pharmacy, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway
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Raknes G, Småbrekke L. A sudden and unprecedented increase in low dose naltrexone (LDN) prescribing in Norway. Patient and prescriber characteristics, and dispense patterns. A drug utilization cohort study. Pharmacoepidemiol Drug Saf 2016; 26:136-142. [PMID: 27670755 PMCID: PMC5298009 DOI: 10.1002/pds.4110] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 07/14/2016] [Accepted: 08/25/2016] [Indexed: 11/19/2022]
Abstract
Purpose Following a TV documentary in 2013, there was a tremendous increase in low dose naltrexone (LDN) use in a wide range of unapproved indications in Norway. We aim to describe the extent of this sudden and unprecedented increase in LDN prescribing, to characterize patients and LDN prescribers, and to estimate LDN dose sizes. Methods LDN prescriptions recorded in the Norwegian Prescription Database (NorPD) in 2013 and 2014, and sales data not recorded in NorPD from the only Norwegian LDN manufacturer were included in the study. Results According to NorPD, 15 297 patients (0.3% of population) collected at least one LDN prescription. The actual number of users was higher as at least 23% of total sales were not recorded in NorPD. After an initial wave, there was a steady stream of new and persistent users throughout the study period. Median patient age was 52 years, and 74% of patients were female. Median daily dose was 3.7 mg. Twenty percent of all doctors and 71% of general medicine practitioners registered in Norway in 2014 prescribed LDN at least once. Conclusions The TV documentary on LDN in Norway was followed by a large increase in LDN prescribing, and the proportion of LDN users went from an insignificant number to 0.3% of the population. There was a high willingness to use and prescribe off label despite limited evidence. Observed median LDN dose, and age and gender distribution were as expected in typical LDN using patients. © 2016 The Authors. Pharmacoepidemiology and Drug Safety Published by John Wiley & Sons Ltd.
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Affiliation(s)
- Guttorm Raknes
- Regional Medicines and Information and Pharmacovigilance Centre (RELIS), University Hospital of North Norway, Tromsø, Norway.,National Centre for Emergency Primary Health Care, Uni Research Health, Bergen, Norway
| | - Lars Småbrekke
- Department of Pharmacy, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway
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