A randomized, double-blind, double-dummy comparison of the efficacy and tolerability of low-dose transdermal buprenorphine (BuTrans seven-day patches) with buprenorphine sublingual tablets (Temgesic) in patients with osteoarthritis pain

Development and Validation of a Treatment Algorithm for Osteoarthritis Pain Management in Patients With End-Stage Kidney Disease Undergoing Hemodialysis

Background

Although osteoarthritis is common in the hemodialysis population and leads to poor health outcomes, pain management is challenged by the absence of clinical guidance. A treatment algorithm was developed and validated to aid hemodialysis clinicians in managing osteoarthritis pain.

Objective

The objective was to develop and validate a treatment algorithm for managing osteoarthritis pain in patients undergoing hemodialysis.

Design

A validation study was conducted based on Lynn's method for content validation.

Setting

To develop and validate a treatment algorithm, interviews were conducted virtually by the primary researcher with clinicians from various institutions across the Greater Toronto and Hamilton Area in Ontario.

Patients

The treatment algorithm was developed and validated for the management of osteoarthritis pain in patients on hemodialysis. Patients were not involved in the development or validation of the tool.

Measurements

The algorithm was measured for content and face validity. Content validity was measured by calculating the content validity index of each component (I-CVI) of the algorithm and the overall scale validity index (S-CVI). Face validity was assessed by calculating the percentage of positive responses to the face validity statements.

Methods

A draft algorithm was developed based on literature searches and expert opinion and validated by interviewing nephrology and pain management clinicians. Through consecutive rounds of 1:1 interviews, content and face validity were assessed by asking participants to rate the relevance of each component of the algorithm and indicate their level of agreeability with a series of statements. Following each round, the I-CVI of the algorithm as well as the S-CVI was calculated and the percentage of positive responses to the statements was determined. The research team revised the algorithm in response to the findings. The final algorithm provides a stepwise approach to the non-pharmacologic and pharmacologic management of pain, including topical, oral, and opioid use.

Results

A total of 18 clinicians from 7 institutions across the Greater Toronto and Hamilton Area were interviewed (10 pharmacists, 5 nurse practitioners, and 3 physicians). The average S-CVI of the algorithm across all 3 rounds was 0.93. At least 78% of participants provided positive responses to the face validity statements.

Limitations

An algorithm was developed based on input from clinicians working in the province of Ontario, limiting the generalizability of the algorithm across provinces. In addition, the algorithm did not include the perspectives of primary care providers or patients/caregivers.

Conclusions

An algorithm for the management of osteoarthritis pain in the hemodialysis population was developed and validated through expert review to standardize practices and encourage clinicians to use evidence-based treatments and address the psychosocial symptoms of pain. As the algorithm possesses a high degree of content and face validity, it may improve osteoarthritis pain management among patients undergoing hemodialysis. Future research will assess the implementation of the algorithm across hemodialysis settings.

Survey of Buprenorphine Low-dose Regimens Used by Healthcare Institutions

BACKGROUND

Buprenorphine microdosing ("low-dosing") allows for initiation of buprenorphine without requiring patients to endure withdrawal. Case studies suggest its favorable utility as an alternative to conventional buprenorphine induction. However, published regimens vary in duration, dosage forms used, and timing of full opioid agonist discontinuation.

METHODS

This cross-sectional survey study sought to determine how buprenorphine low-dosing is approached by medical institutions across the United States. The primary end point was characterization of inpatient buprenorphine low-dosing regimens. Situations and types of patients in which low-dosing is used and obstacles to institutional protocol development were also collected. An online survey was disseminated through professional pharmacy organizations and personal contacts. Responses were collected over 4 weeks.

RESULTS

Twenty-three unique protocols were collected from 25 institutions. Most protocols used buccal (8 protocols) or transdermal (8 protocols) buprenorphine as first doses before transitioning to sublingual buprenorphine. The most common starting doses were buprenorphine 20 μg/h transdermal, 150 μg buccal, and 0.5 mg sublingual. Patients unable to tolerate conventional buprenorphine induction or those who potentially used fentanyl nonmedically were most likely to be prescribed low-dosing. The most common obstacle to developing an internal low-dosing protocol was lack of existing consensus guidelines.

CONCLUSIONS

Similar to published regimens, internal protocols are variable. Buccal first doses may be used more commonly in practice based on survey results, while transdermal first doses are more commonly reported in publications. More research is needed to determine whether differences in starting formulations impact safety and efficacy of buprenorphine low-dosing in the inpatient setting.

Analgesic Effect of Buprenorphine for Chronic Noncancer Pain: A Systematic Review and Meta-analysis of Randomized Controlled Trials

BACKGROUND

Buprenorphine is a partial agonist at the µ-opioid receptor and an antagonist at the delta and kappa opioid receptors. It has high affinity and low intrinsic activity at the µ-opioid receptor. Buprenorphine demonstrates no ceiling effect for clinical analgesia, but demonstrates this for respiratory depression and euphoria. It may provide effective analgesia while producing less adverse effects, making it a promising opioid analgesic. A systematic review and meta-analysis were performed to examine the analgesic efficacy of buprenorphine for patients with chronic noncancer pain.

METHODS

PubMed, MEDLNE, Embase, and the Cochrane Library were searched up to January 2022. Randomized controlled trials were included if they compared buprenorphine versus placebo or active analgesic in patients with chronic noncancer pain, where pain score was an outcome. Nonrandomized controlled trials, observational studies, qualitative studies, case reports, and commentaries were excluded. Two investigators independently performed the literature search, study selection, and data collection. A random-effects model was used. The primary outcome was the effect of buprenorphine on pain intensity in patients with chronic noncancer pain based on standardized mean difference (SMD) in pain score. Quality of evidence was assessed using the Grade of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

RESULTS

Two separate literature searches were conducted for patients with and without opioid use disorder (OUD). Only one study met the search criteria for those with OUD. Fourteen randomized controlled trials were included for those without OUD. Buprenorphine was associated with reduced pain score (SMD = -0.368, P < .001, I 2 = 89.37%) compared to placebo or active analgesic. Subgroup meta-analyses showed statistically significant differences in favor of buprenorphine versus placebo (SMD = -0.404, P < .001), for chronic low back pain (SMD = -0.383, P < .001), when administered via the transdermal route (SMD = -0.572, P = .001), via the buccal route (SMD = -0.453, P < .001), with length of follow-up lasting <12 weeks (SMD = -0.848, P < .05), and length of follow-up lasting 12 weeks or more (SMD = -0.415, P < .001). There was no significant difference when compared to active analgesic (SMD = 0.045, P > .05). Quality of evidence was low to moderate.

CONCLUSIONS

Buprenorphine was associated with a statistically significant and small reduction in pain intensity compared to placebo. Both the transdermal and buccal routes provided pain relief. There was more evidence supporting its use for chronic low back pain.

Recent Advancement of Medical Patch for Transdermal Drug Delivery

Transdermal patches are a non-invasive method of drug administration. It is an adhesive patch designed to deliver a specific dose of medication through the skin and into the bloodstream throughout the body. Transdermal drug delivery has several advantages over other routes of administration, for instance, it is less invasive, patient-friendly, and has the ability to bypass first-pass metabolism and the destructive acidic environment of the stomach that occurs upon the oral ingestion of drugs. For decades, transdermal patches have attracted attention and were used to deliver drugs such as nicotine, fentanyl, nitroglycerin, and clonidine to treat various diseases or conditions. Recently, this method is also being explored as a means of delivering biologics in various applications. Here, we review the existing literatures on the design and usage of medical patches in transdermal drug delivery, with a focus on the recent advances in innovation and technology that led to the emergence of smart, dissolvable/biodegradable, and high-loading/release, as well as 3D-printed patches.

A review of the safety of buprenorphine in special populations

Rates of opioid misuse and opioid use disorder have been increasing in recent years. Buprenorphine has emerged as an appealing medication for its use not only as treatment for opioid use disorder, but also as an opioid for chronic pain that has a ceiling effect on risks associated with opioid therapy. As other opioid prescribing decreases, buprenorphine prescribing continues to increase. As a result, it is imperative to understand the safety and efficacy of its use in special populations. This review article will explore the safety and efficacy of buprenorphine when used in subjects with hepatic and renal impairment, the elderly, and pregnant women. While manufacturer labeling for buprenorphine products may caution against their use in these populations, further examination of available data indicates that buprenorphine can be used safely and effectively for both chronic pain and/or opioid use disorder in all four of these populations.

Comparative benefits and harms of individual opioids for chronic non-cancer pain: a systematic review and network meta-analysis of randomised trials

BACKGROUND

Most systematic reviews of opioids for chronic pain have pooled treatment effects across individual opioids under the assumption they provide similar benefits and harms. We examined the comparative effects of individual opioids for chronic non-cancer pain through a network meta-analysis of randomised controlled trials.

METHODS

We searched MEDLINE, EMBASE, CINAHL, and the Cochrane Central Register of Controlled Trials to March 2021 for studies that enrolled patients with chronic non-cancer pain, randomised them to receive different opioids, or opioids vs placebo, and followed them for at least 4 weeks. Certainty of evidence was evaluated using the GRADE approach.

RESULTS

We identified 82 eligible trials (22 619 participants) that evaluated 14 opioids. Compared with placebo, several opioids showed superiority to others for analgesia and improvement in physical function; however, when restricted to pooled-effect estimates supported by moderate certainty evidence, no differences between opioids were evident. Among opioids with moderate certainty evidence, all increased the risk of gastrointestinal adverse events compared with placebo, although no opioids were more harmful than others. Low to very low certainty evidence suggests that extended-release vs immediate-release opioids may provide similar benefits for pain relief and physical functioning, and gastrointestinal harms.

CONCLUSIONS

Our findings support the pooling of effect estimates across different types and formulations of opioids to inform effectiveness for chronic non-cancer pain.

Buprenorphine for Chronic Pain: A Safer Alternative to Traditional Opioids

With the ongoing public health crisis with prescription opioids, there is a need for safer alternatives for medication management in chronic pain patients. Buprenorphine is a partial mu-opioid agonist which is commonly utilized to treat patients with opioid-use disorders. The purpose of this review is to discuss the potential use of this medication for the treatment of chronic pain instead of resorting to more traditional Schedule II opioids. Buprenorphine offers a safer alternative for patients who require opioids to manage chronic pain, given the unique pharmacological properties that allow it to provide adequate analgesia with less abuse potential.

Strategies for transdermal drug delivery against bone disorders: A preclinical and clinical update

The transdermal drug delivery system is an exceptionally safe and well-tolerable therapeutic approach that has immense potential for delivering active components against bone-related pathologies. However, its use is limited in the current clinical practices due to the low skin permeability of most active drugs in the formulation. Thus, innovations in the methodologies of skin permeation enhancement techniques are suggested to overcome this limitation. Although various transdermal drug delivery systems are studied to date, there are insufficient studies comparing the therapeutic efficacy of transdermal delivery systems to oral delivery systems. Thus, creating a decision-making dilemma between oral or transdermal therapies. Therefore, a timely review is inevitable to develop a platform for future researchers to develop next-generation transdermal drug delivery strategies against skeletal diseases that must be convenient and cost-effective for the patients with improved therapeutic efficacy. Here, we will outline the most recent strategies that can overcome the choice limitation of the drug and enhance the transdermal adsorption of various types of drugs to treat bone disorders. For the first time, in this review paper, we will highlight the preclinical and clinical studies on the different transdermal delivery methods. Thus, providing insight into the current therapeutic approaches and suggesting new directions for the advancements in transdermal drug delivery systems against bone disorders.

Is Buprenorphine Effective for Chronic Pain? A Systematic Review and Meta-analysis

OBJECTIVE

The objective was to perform a systematic review and meta-analysis of the literature on the effects of buprenorphine on chronic pain outcomes (i.e., patient-reported pain intensity) in patients with and without opioid use disorder (OUD).

DESIGN

Ovid/Medline, PubMed, Embase, and the Cochrane Library were searched for studies that explored the effectiveness (in reducing pain) of buprenorphine treatment for chronic pain patients with and without a history of OUD. Randomized controlled trials and observational studies were included in the review.

METHODS

Two separate searches were conducted to identify buprenorphine trials that included chronic pain patients either with or without OUD. Five studies used validated pain report measures and included a chronic pain population with OUD. Nine studies used validated report measures and included chronic pain patients without OUD. Meta-analysis was performed using the R, version 3.2.2, Metafor package, version 1.9-7.

RESULTS

The meta-analysis revealed that buprenorphine has a beneficial effect on pain intensity overall, with a small mean effect size in patients with comorbid chronic pain and OUD and a moderate- to large-sized effect in chronic pain patients without OUD.

CONCLUSIONS

Our results indicate that buprenorphine is modestly beneficial in reducing pain intensity in patients without OUD. Although informative, these findings should be carefully interpreted due to the small amount of data available and the variation in study designs.

Buprenorphine buccal film for chronic pain management

Buprenorphine is a Schedule III opioid with unique pharmacodynamic and pharmacokinetic properties that contribute to effective analgesia and fewer safety risks than other opioids. This review article focuses on the buccal film formulation, which is preferable to other buprenorphine formulations on the basis of bioavailability, safety and efficacy. The clinical studies reviewed here confirm that buprenorphine buccal film offers effective and continuous pain relief that is generally well tolerated, with no cases of respiratory depression reported in any of the studies. On the basis of these clinical data and individual patient risk/benefit assessments, clinicians should consider utilizing buprenorphine buccal film as a first-line opioid treatment for chronic pain over other buprenorphine formulations or other opioids.

Safety And Efficacy Of The Unique Opioid Buprenorphine For The Treatment Of Chronic Pain

BACKGROUND

Chronic pain is associated with decreased quality of life and is one of the most common reasons adults seek medical care, making treatment imperative for many aspects of patient well-being. Chronic pain management typically involves the use of Schedule II full μ-opioid receptor agonists for pain relief; however, the increasing prevalence of opioid addiction is a national crisis that is impacting public health and social and economic welfare. Buprenorphine is a Schedule III partial μ-opioid receptor agonist that is an equally effective but potentially safer treatment option for chronic pain than full μ-opioid receptor agonists. The purpose of this review is to provide an overview of the clinical efficacy and safety of the transdermal and buccal formulations of buprenorphine, which are approved by the Food and Drug Administration for chronic pain, compared with that of extended-release full μ-opioid receptor agonists.

METHODS

Controlled or randomized controlled clinical trial information was retrieved from EMBASE, Medline, and PubMed using the search terms "buprenorphine" AND "chronic" AND "pain."

RESULTS

A total of 33 clinical studies were ultimately used in this review, including 29 (88%) on transdermal buprenorphine and 4 (12%) on buprenorphine buccal film. Although the measure of pain intensity varied among studies, each of these 33 trials demonstrated efficacy for buprenorphine in pain relief. A total of 28 studies also assessed safety, with each concluding that buprenorphine was generally well tolerated.

CONCLUSION

Comparison of current clinical data along with results of responder and safety analyses support the use of buprenorphine over full μ-opioid receptor agonists for effective preferential treatment of chronic pain; however, head-to-head clinical studies are warranted.

Converting from Transdermal to Buccal Formulations of Buprenorphine: A Pharmacokinetic Meta-Model Simulation in Healthy Volunteers

Objective

To develop a model to predict buprenorphine plasma concentrations during transition from transdermal to buccal administration.

Design

Population pharmacokinetic model-based meta-analysis of published data.

Methods

A model-based meta-analysis of available buprenorphine pharmacokinetic data in healthy adults, extracted as aggregate (mean) data from published literature, was performed to explore potential conversion from transdermal to buccal buprenorphine. The time course of mean buprenorphine plasma concentrations following application of transdermal patch or buccal film was digitized from available literature, and a meta-model was developed using specific pharmacokinetic parameters (e.g., absorption rate, apparent clearance, and volumes of distribution) derived from analysis of pharmacokinetic data for intravenously, transdermally, and buccally administered buprenorphine.

Results

Data from six studies were included in this analysis. The final transdermal absorption model employed a zero-order input rate that was scaled to reflect a nominal patch delivery rate and time after patch application (with decline in rate over time). The transdermal absorption rate constant became zero following patch removal. Buccal absorption was a first-order process with a time lag and bioavailability term. Simulations of conversion from transdermal 20 mcg/h and 10 mcg/h to buccal administration suggest that transition can be made rapidly (beginning 12 hours after patch removal) using the recommended buccal formulation titration increments (75-150 mcg) and schedule (every four days) described in the product labeling.

Conclusions

Computer modeling and simulations using a meta-model built from data extracted from publications suggest that rapid and straightforward conversion from transdermal to buccal buprenorphine is feasible.

Evaluation of Analgesic Patches in Cynomolgus Macaques (Macaca fascicularis)

Opioids are widely used in veterinary and human medicine to manage pain. However, there is a paucity of information in the literature regarding the pharmacokinetics of opioid transdermal patches (TDP) in NHP. Therefore, to determine whether opioid TDP attain therapeutic concentrations in NHP, the pharmacokinetics of fentanyl (25 μg/h) and buprenorphine (10 and 20 μg/h) TDP were evaluated in naïve, adult, male cynomolgus macaques (n = 4) in a crossover study. Plasma opioid levels were determined by tandem liquid chromatography-mass spectrometry. The AUC_0-inf for fentanyl and the low and high dose buprenorphine patches were 115 ± 14, 462 ± 74, and 778 ± 344 ng× h/mL, and the plasma half-lifes were 22 ± 4, 77 ± 27, and 42 ± 11 h, respectively. No adverse effects were noted throughout the study. Minimal therapeutic concentrations for fentanyl (0.2 ng/mL) and buprenorphine (0.1 ng/mL) were achieved in all macaques within 8 h of fentanyl and 24 h of buprenorphine TDP application. Therapeutic levels for the fentanyl and low- and high-dose buprenorphine patches were maintained for 96, 120, and 144 h, respectively. These findings suggest that 25-μg/h fentanyl patches should be replaced every 4 d, and the low- and high-dose buprenorphine patches should be replaced every 5 and 6 d, respectively. The results of this study show that fentanyl and buprenorphine patches achieve minimal therapeutic levels for clinically relevant periods of time and should be considered viable options for pain management in cynomolgus macaques.

Transdermal buprenorphine patch: Potential for role in management of opioid dependence

Despite proven clinical utility, use of sublinugual buprenorphine is fraught with issues of potential diversion among patients with opioid dependence. Transdermal buprenorphine patches provide an alternative delivery model that can be utilized to reduce such diversion. This narrative review discusses the transdermal buprenorphine formulations, and its pharmacology, drug interaction and tolerability profile. The studies utilizing buprenorphine transdermal patches in the treatment of opioid dependence are examined, while the potential of using such patches for maintenance treatment of opioid dependence is examined.

Treating Chronic Pain: An Overview of Clinical Studies Centered on the Buprenorphine Option

The buprenorphine receptor binding profile is unique in that it binds to all three major opioid receptors (mu, kappa, delta), and also binds to the orphan-like receptor, the receptor for orphanin FQ/nociceptin, with lower affinity. Within the mu receptor group, buprenorphine analgesia in rodents is dependent on the recently discovered arylepoxamide receptor target in brain, which involves a truncated 6-transmembrane mu receptor gene protein, distinguishing itself from morphine and most other mu opioids. Although originally designed as an analgesic, buprenorphine has mainly been used for opioid maintenance therapy and only now is increasingly recognized as an effective analgesic with an improved therapeutic index relative to certain potent opioids. Albeit a second-, third-, or fourth-line analgesic, buprenorphine is a reasonable choice in certain clinical situations. Transdermal patches and buccal film formulations are now commercially available as analgesics. This review discusses buprenorphine pharmacodynamics and pharmacokinetics, use in certain populations, and provides a synopsis of systematic reviews and randomized analgesic trials. We briefly discuss postoperative management in patients receiving buprenorphine maintenance therapy, opioid equivalence to buprenorphine, rotations to buprenorphine from other opioids, and clinical relevance of buprenorphine-related QTc interval changes.

Transdermal buprenorphine for moderate chronic noncancer pain syndromes

Introduction: Chronic noncancer pain has remained a challenging clinical problem. Opioid analgesics are effective, but they are known to be associated with opioid use disorder and potentially treatment-limiting side effects. Buprenorphine is a Schedule III synthetic opioid in the USA with a chemical structure similar to that of morphine but with a longer duration of action, greater potency, and other unique pharmacological attributes. Its role in treatment of chronic noncancer pain may be broader than currently thought.Areas covered: The pharmacokinetics, pharmacodynamics, clinical efficacy, and safety profile of transdermal buprenorphine in moderate chronic noncancer pain syndromes patients will be discussed.Expert commentary: Buprenorphine offers effective analgesia in the form of a Schedule III drug (rather than Schedule II such as oxycodone or morphine) and transdermal buprenorphine is a convenient, accepted, around-the-clock pain reliever. Its lower potential for abuse should make it a more desirable pain reliever but many payers do not reimburse buprenorphine, driving prescribers and their patients to generic versions of the riskier Schedule II oral opioids such as oxycodone and morphine.

Use of immediate-release opioids as supplemental analgesia during management of moderate-to-severe chronic pain with buprenorphine transdermal system

Background

The buprenorphine transdermal system (BTDS) is approved in the US for the management of chronic pain. Due to its high affinity for μ-opioid receptors with a slow dissociation profile, buprenorphine may potentially displace or prevent the binding of competing μ-opioid-receptor agonists, including immediate-release (IR) opioids, in a dose-dependent manner. Health care professionals may assume that the use of IR opioids for supplemental analgesia during BTDS therapy is not acceptable.

Materials and methods

This post hoc analysis evaluated the use of IR opioids as supplemental analgesia during the management of moderate–severe chronic pain with BTDS at 52 US sites (BUP3015S, NCT01125917). Patients were categorized into IR-opioid and no-IR-opioid groups. At each visit of the extension phase, adverse events, concomitant medications, and information from the Brief Pain Inventory (BPI) were recorded.

Results

The most common supplemental IR opioids prescribed during BTDS treatment (n=354) were hydrocodone–acetaminophen and oxycodone–acetaminophen. The mean daily dose of IR opioids (morphine equivalents) for supplemental analgesia was 22 mg. At baseline, BPI – pain intensity and BPI – interference scores were higher for patients in the IR-opioid group. In both treatment groups, scores improved by week 4, and then were maintained throughout 6 months of the open-label extension trial. The incidence of treatment-emergent adverse events was similar in both groups.

Conclusion

Patients who were prescribed IR opioids reported lower scores for BPI pain intensity and pain interference to levels similar to patients receiving BTDS without IR opioids, without increasing the rate or severity of treatment-emergent adverse events. Patients prescribed concomitant use of IR opioids with BTDS had greater treatment persistence. The results of this post hoc analysis provide support for the concomitant use of IR opioids for supplemental analgesia during the management of moderate–severe chronic pain with BTDS.

Satisfaction, Adherence and Health-Related Quality of Life with Transdermal Buprenorphine Compared with Oral Opioid Medications in the Usual Care of Osteoarthritis Pain

Background

Osteoarthritis (OA) causes substantial pain and reduced health-related quality of life (HRQL). Although opioid analgesics are commonly used, the relative benefits of different opioids are poorly studied. Transdermal buprenorphine (TDB) offers an alternative to oral opioids for the treatment of moderate-to-severe chronic pain. This observational study of people with OA pain assessed satisfaction, HRQL and medication adherence.

Methods

Patients in the UK with self-reported knee and/or hip OA who had been receiving one or more of TDB, co-codamol (an oral paracetamol/codeine combination) and tramadol for at least 1 month completed an online or telephone questionnaire. Medication satisfaction scores, HRQL scores (Short-Form 36 [SF-36]), medication adherence (Morisky Medication Adherence Scale [MMAS™]), adverse events and treatment discontinuations were recorded. Linear and logistic regression models were used to compare the treatment effect of TDB with co-codamol or tramadol.

Results

Overall, 966 patients met the inclusion criteria; 701 were taking only one of the target medications (TDB: 85; co-codamol: 373; tramadol: 243). The largest age group was 50–59 years and 76.0 % of patients were female. The TDB group was younger, with more male patients, therefore the statistical models were adjusted for age and sex. Medication satisfaction scores were significantly higher in the TDB group than the other two groups (TDB vs. co-codamol: 3.56, 95 % confidence interval [CI] 1.90–6.68, p < 0.0001; TDB vs. tramadol: 3.22, 95 % CI 1.67–6.20, p = 0.0005). Physical Component Summary scores for HRQL and mean adherence were also higher in the TDB group, while Mental Component Summary HRQL scores were similar across the three groups.

Conclusions

Patients with knee and/or hip OA pain treated with TDB were more satisfied and more adherent with their medication, and reported higher Physical Component Summary HRQL scores than those treated with co-codamol or tramadol, although demographic differences were observed between groups.

Electronic supplementary material

The online version of this article (doi:10.1007/s40271-016-0181-0) contains supplementary material, which is available to authorized users.

Effects of buprenorphine on QT intervals in healthy subjects: results of 2 randomized positive- and placebo-controlled trials

OBJECTIVES

To study the effect of transdermal buprenorphine on QTc prolongation at dose levels of 10, 40, and 80 mcg/h, (BTDS 10, BTDS 40, BTDS 80).

METHODS

Two randomized, placebo- and positive-controlled, parallel-group, dose-escalating clinical studies evaluated healthy adult subjects randomized to BTDS, placebo, or moxifloxacin in the first study; and to BTDS only, BTDS plus naltrexone, naltrexone alone at the same dose, placebo, or moxifloxacin in the second study. QT intervals were corrected for heart rate using data from each individual subject (QTcI).

RESULTS

In the first study (n = 44), the maximum upper bounds of the 90% confidence interval (CI) for mean placebo-corrected change from baseline in QTcI across 13 time points over 24 h were: 10.0 msec for BTDS 10 (Day 6) and 13.3 msec for BTDS 40 (Day 13); and 17.0 msec (Day 6) and 15.5 msec (Day 13) for moxifloxacin, respectively.  Similarly, in the second study (n = 66), the upper bound of the 90% CI for mean placebo-corrected change from baseline for QTcI was under 10 msec at all time points for BTDS 10 (maximum upper bound, 5.63 msec), over 10 msec at 5 time points for BTDS 40 (maximum 11.81 msec) and over 10 msec at all 13 time points for BTDS 80 (maximum, 14.14 msec). Naltrexone administered with BTDS eliminated the QTcI prolongation seen with supratherapeutic BTDS doses (BTDS 40, BTDS 80) administered without naltrexone.

CONCLUSIONS

At the therapeutic dose of 10 mcg/h, BTDS has no clinically significant effect on QTc. At supratherapeutic doses of 40 and 80 mcg/h, BTDS treatment produces prolongation of QTcI similar in magnitude to that produced by a 400 mg dose of moxifloxacin. Despite the modest, dose-dependent increase in QTcI noted in these studies, transdermal buprenorphine has not been associated with proarrhythmic effects.

Assessment of Transdermal Buprenorphine Patches for the Treatment of Chronic Pain in a UK Observational Study

BACKGROUND

Opioids provide effective analgesia for moderate-to-severe, chronic pain. Transdermal buprenorphine (TDB) is available in the UK as weekly, lower-dose (5-20 μg/h) patches and twice-weekly, higher dose (35-70 μg/h) patches. This prospective, observational, multicenter study of patients with various chronic pain conditions assessed the safety, perceptions, and discontinuation of treatment with TDB in a real-world, non-interventional setting (ClinicalTrials.gov study ID: NCT01225861).

METHODS

Patients aged ≥18 years who were already receiving or initiating treatment with TDB were recruited in the UK during routine clinical visits and were followed for 6 visits or 9 months (whichever came first). Self-reported treatment adherence, patient satisfaction, and safety data were collected at each study visit.

RESULTS

Of 465 patients, 272 were already receiving 7-day TDB at the study start (TDB experienced), 146 were TDB naïve, and 47 were prescribed twice-weekly TDB. Most patients were female (72.9 %) and overweight/obese (body mass index ≥25: 75.3 %). The median age was 67 years, and the mean duration of pain was 11.1 years. Arthritis/other musculoskeletal disorders (39.6 %) were the most common causes of pain. Mild adverse events were commonly reported. Skin irritations, which were most frequent in 7-day TDB-experienced patients (45.6 %), rarely resulted in treatment discontinuation (8.8 %). Nearly all patients used TDB in accordance with treatment recommendations. Most patients reported that TDB was 'effective'/'very effective' at relieving pain and were 'satisfied'/'very satisfied' with TDB therapy.

CONCLUSION

In everyday clinical practice, TDB was well tolerated and patients were satisfied with their therapy. Self-reported adherence to TDB was very high, and adverse events rarely resulted in treatment discontinuation. Opportunities were identified to limit common adverse events associated with TDB.

Carriers for the tunable release of therapeutics: etymological classification and examples

Introduction Physiological processes at the molecular level take place at precise spatiotemporal scales, which vary from tissue to tissue and from one patient to another, implying the need for carriers that enable tunable release of therapeutics. Areas covered Classification of all drug release to intrinsic and extrinsic is proposed, followed by the etymological clarification of the term 'tunable' and its distinction from the term 'tailorable'. Tunability is defined as analogous to tuning a guitar string or a radio receiver to the right frequency using a single knob. It implies changing a structural parameter along a continuous quantitative scale and correlating it numerically with the release kinetics. Examples of tunable, tailorable and environmentally responsive carriers are given, along with the parameters used to achieve these levels of control. Expert opinion Interdependence of multiple variables defining the carrier microstructure obstructs the attempts to elucidate parameters that allow for the independent tuning of release kinetics. Learning from the tunability of nanostructured materials and superstructured metamaterials can be a fruitful source of inspiration in the quest for the new generation of tunable release carriers. The greater intersection of traditional materials sciences and pharmacokinetic perspectives could foster the development of more sophisticated mechanisms for tunable release.

Effectiveness and Safety of Transdermal Buprenorphine Versus Sustained-release Tramadol in Patients With Moderate to Severe Musculoskeletal Pain: An 8-Week, Randomized, Double-Blind, Double-Dummy, Multicenter, Active-controlled, Noninferiority Study

OBJECTIVES

The aim of this noninferiority study was to investigate clinical effectiveness and safety of buprenorphine transdermal system (BTDS) in patients with moderate to severe musculoskeletal pain inadequately controlled with nonsteroidal anti-inflammatory drugs, compared with sustained-release tramadol tablets.

MATERIALS AND METHODS

Eligible patients were randomized (1:1) to receive low-dose 7-day BTDS (5, 10, and 20 μg/h, maximum dosage of 20 μg/h) or sustained-release tramadol tablets (100 mg, maximum dosage of 400 mg/d) over an 8-week double-blind treatment period (3-week titration, 5-week maintenance). The primary endpoint was the difference in the visual analogue scale (VAS) pain scores from baseline to treatment completion. Noninferiority was assumed if the treatment difference on the VAS scale was within ±1.5 cm, this threshold indicating a clinically meaningful result. ClinicalTrials.gov identifier: NCT01476774.

RESULTS

Two hundred eighty patients were randomized to BTDS (n=141) or to tramadol (n=139). Both treatments were associated with a significant reduction in pain by the end of the treatment. The least squares mean difference of the change from baseline in VAS scores between the BTDS and tramadol groups were 0.45 (95% confidence interval, -0.02 to 0.91), which was within the ±1.5 cm predefined threshold, indicating that the effectiveness of BTDS was not inferior to the effectiveness of sustained-release tramadol tablets. The incidence of adverse events was comparable between the 2 treatment groups.

CONCLUSIONS

Our results suggest that BTDS is a good therapeutic option for patients experiencing chronic musculoskeletal pain of moderate to severe intensity that is insufficiently controlled by nonsteroidal anti-inflammatory drugs.

Crystallographic textures and morphologies of solution cast Ibuprofen composite films at solid surfaces

The preparation of thin composite layers has promising advantages in a variety of applications like transdermal, buccal, or sublingual patches. Within this model study the impact of the matrix material on the film forming properties of ibuprofen–matrix composite films is investigated. As matrix materials polystyrene, methyl cellulose, or hydroxyl-ethyl cellulose were used. The film properties were either varied by the preparation route, i.e., spin coating or drop casting, or via changes in the relative ratio of the ibuprofen and the matrix material. The resulting films were investigated via X-ray diffraction and atomic force microscope experiments. The results show that preferred (100) textures can be induced via spin coating with respect to the glass surface, while the drop casting results in a powder-like behavior. The morphologies of the films are strongly impacted by the ibuprofen amount rather than the preparation method. A comparison of the various matrix materials in terms of their impact on the dissolution properties show a two times faster zero order release from methyl cellulose matrix compared to a polystyrene matrix. The slowest rate was observed within the hydroxyl ethyl cellulose as the active pharmaceutical ingredients (APIs) release is limited by diffusion through a swollen matrix. The investigation reveals that the ibuprofen crystallization and film formation is only little effected by the selected matrix material than that compared to the dissolution. A similar experimental approach using other matrix materials may therefore allow to find an optimized composite layer useful for a defined application.

Oral or transdermal opioids for osteoarthritis of the knee or hip

BACKGROUND

Osteoarthritis is the most common form of joint disease and the leading cause of pain and physical disability in older people. Opioids may be a viable treatment option if people have severe pain or if other analgesics are contraindicated. However, the evidence about their effectiveness and safety is contradictory. This is an update of a Cochrane review first published in 2009.

OBJECTIVES

To determine the effects on pain, function, safety, and addiction of oral or transdermal opioids compared with placebo or no intervention in people with knee or hip osteoarthritis.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and CINAHL (up to 28 July 2008, with an update performed on 15 August 2012), checked conference proceedings, reference lists, and contacted authors.

SELECTION CRITERIA

We included randomised or quasi-randomised controlled trials that compared oral or transdermal opioids with placebo or no treatment in people with knee or hip osteoarthritis. We excluded studies of tramadol. We applied no language restrictions.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate. We calculated standardised mean differences (SMDs) and 95% confidence intervals (CI) for pain and function, and risk ratios for safety outcomes. We combined trials using an inverse-variance random-effects meta-analysis.

MAIN RESULTS

We identified 12 additional trials and included 22 trials with 8275 participants in this update. Oral oxycodone was studied in 10 trials, transdermal buprenorphine and oral tapentadol in four, oral codeine in three, oral morphine and oral oxymorphone in two, and transdermal fentanyl and oral hydromorphone in one trial each. All trials were described as double-blind, but the risk of bias for other domains was unclear in several trials due to incomplete reporting. Opioids were more beneficial in pain reduction than control interventions (SMD -0.28, 95% CI -0.35 to -0.20), which corresponds to a difference in pain scores of 0.7 cm on a 10-cm visual analogue scale (VAS) between opioids and placebo. This corresponds to a difference in improvement of 12% (95% CI 9% to 15%) between opioids (41% mean improvement from baseline) and placebo (29% mean improvement from baseline), which translates into a number needed to treat (NNTB) to cause one additional treatment response on pain of 10 (95% CI 8 to 14). Improvement of function was larger in opioid-treated participants compared with control groups (SMD -0.26, 95% CI -0.35 to -0.17), which corresponds to a difference in function scores of 0.6 units between opioids and placebo on a standardised Western Ontario and McMaster Universities Arthritis Index (WOMAC) disability scale ranging from 0 to 10. This corresponds to a difference in improvement of 11% (95% CI 7% to 14%) between opioids (32% mean improvement from baseline) and placebo (21% mean improvement from baseline), which translates into an NNTB to cause one additional treatment response on function of 11 (95% CI 7 to 14). We did not find substantial differences in effects according to type of opioid, analgesic potency, route of administration, daily dose, methodological quality of trials, and type of funding. Trials with treatment durations of four weeks or less showed larger pain relief than trials with longer treatment duration (P value for interaction = 0.001) and there was evidence for funnel plot asymmetry (P value = 0.054 for pain and P value = 0.011 for function). Adverse events were more frequent in participants receiving opioids compared with control. The pooled risk ratio was 1.49 (95% CI 1.35 to 1.63) for any adverse event (9 trials; 22% of participants in opioid and 15% of participants in control treatment experienced side effects), 3.76 (95% CI 2.93 to 4.82) for drop-outs due to adverse events (19 trials; 6.4% of participants in opioid and 1.7% of participants in control treatment dropped out due to adverse events), and 3.35 (95% CI 0.83 to 13.56) for serious adverse events (2 trials; 1.3% of participants in opioid and 0.4% of participants in control treatment experienced serious adverse events). Withdrawal symptoms occurred more often in opioid compared with control treatment (odds ratio (OR) 2.76, 95% CI 2.02 to 3.77; 3 trials; 2.4% of participants in opioid and 0.9% of participants control treatment experienced withdrawal symptoms).

AUTHORS' CONCLUSIONS

The small mean benefit of non-tramadol opioids are contrasted by significant increases in the risk of adverse events. For the pain outcome in particular, observed effects were of questionable clinical relevance since the 95% CI did not include the minimal clinically important difference of 0.37 SMDs, which corresponds to 0.9 cm on a 10-cm VAS.

US practitioner prescribing practices and patient characteristics of those newly treated with a buprenorphine transdermal patch system

OBJECTIVES

Medication prescribing information provides guidance to healthcare providers on how to prescribe a drug properly. Oftentimes patient factors in addition to the prescribing information are considered when selecting medications. Utilizing real-world pharmacy and medical claims data, this study assessed US practitioner prescribing practices of US approved transdermal buprenorphine system (BTDS) in relation to BTDS's full prescribing information (FPI) as well as the relationship between patient factors and initial BTDS dose.

RESEARCH DESIGN AND METHODS

Patients aged ≥18 years initiating BTDS between 1 January 2011 and 30 November 2011 were identified in the IMS Pharmacy and Private Practitioner Medical Claims databases. The index date was defined as the first filled BTDS prescription. Demographics, chronic pain-related medical conditions in the 12 months pre-index and prior medication use in the 6 months pre-index were assessed. Initial BTDS dosing strength, receipt of approved initial BTDS dose per the FPI, and concomitant medications were assessed in the post-index 6 month period.

RESULTS

The study included 10,457 patients newly treated with BTDS. The majority of patients were female (69.9%) with a mean (±SD) age of 54.5 (±15.2) years. Within the 6 months prior to the index BTDS prescription, 91.7% of the patients used opioids. Overall, 48.9% of patients were prescribed the FPI approved BTDS dose. When stratified, 73.5% of opioid-naïve patients received the FPI approved initial dose compared to 46.0% of those with prior opioid experience of ≤80 mg morphine-equivalent daily dose. Patients on BTDS alone (i.e. monotherapy) had a higher rate of receiving the FPI approved initial BTDS dose compared to patients on BTDS concomitant regimens (p < 0.05).

CONCLUSIONS

Practitioners demonstrated that they prescribe in accordance with BTDS's prescribing information in the majority of opioid-naïve patients and in approximately half of opioid-experienced patients. The initial opioid dose is a critical step in treatment, setting the stage for preventing side-effects and improving treatment effectiveness. Understanding practitioner prescribing practices with regard to the initial dose selection of BTDS may provide insight on how to improve outcomes of care and reduce healthcare resource utilization and costs associated with pain management.

LIMITATIONS

Data obtained from prescription claims reflect only the activities of prescriptions filled, not medication use or other clinical characteristics observed by physicians when treating patients.

Sublingual buprenorphine as an analgesic in chronic pain: a systematic review

OBJECTIVE

There is growing interest in the use of sublingual buprenorphine for the treatment of chronic pain due to the unique pharmacology of buprenorphine, widespread use of the transdermal buprenorphine patch for chronic pain, and recent availability of sublingual buprenorphine tablets for the treatment of opioid dependence. The aim of this systematic review was to evaluate the evidence from clinical trials that have assessed the effectiveness of sublingual buprenorphine for chronic pain analgesia.

METHODS

Electronic searches of MEDLINE, Embase, CINAHL, Web of Science, and the Cochrane Database of Systematic Reviews were used to identify clinical trials of sublingual buprenorphine for the treatment of chronic pain.

RESULTS

Ten trials involving 1,190 patients were included in the review. Due to heterogeneity of studies, pooling of the results and meta-analysis were not possible. All studies reported that sublingual buprenorphine demonstrated some effectiveness as a chronic pain analgesic. The majority of studies were observational and of low quality.

CONCLUSIONS

Preliminary trials suggest a plausible role; however, due to a paucity of high-quality trials, the current evidence is insufficient to determine the effectiveness of sublingual buprenorphine for the treatment of chronic pain. Rigorous further trials are warranted.

Retrospective analysis of 4 years of clinical experience with transdermal buprenorphine (Transtec®) in post-traumatic pain

SUMMARY: 

Aims: To evaluate the effectiveness and safety of transdermal buprenorphine (BTDS) in the treatment of post-traumatic pain in a working population. Patients & methods: Retrospective case series of patients with severe post-traumatic pain treated with BTDS between 2008 and 2012. Results: 57 patients were evaluated: 38 men, 19 women (mean age 43 years); patients with burns (n = 22), skin degloving (14), open dislocations (eight), traumatic nerve lesions (six), spinal cord injury (four) and limb amputations (three). 25, 12 and 20 patients experienced neuropathic pain, nociceptive pain or neuropathic/nociceptive pain, respectively. The mean baseline DN4 questionnaire and pain intensity scores were 4.8±2.3 and 7.4±1.5, respectively. The mean duration of pain before BTDS use was 24.4 months (>3 months in 65% of patients). Total patient-years of BTDS treatment were 73. After 14.7±14.9 months of BTDS treatment, mean pain intensity was reduced by 4.2±2.2 points, 38 patients (66.7%) had ≥50% pain relief, 69% reported functional improvement, especially in gait ability (25) and activities of daily life (14), and 46 patients (80.7%) had improved sleep quality. The starting dose of BTDS was 4.4–17.5 μg/h; maintenance dose was 8.8–70 μg/h. At the start of BTDS treatment, all patients used a total of 187 concomitant analgesics daily, 72% of which were stopped during treatment with BTDS; the number of patients that could be managed exclusively with BTDS and rescue analgesia increased to 31%. 13 patients (22%) presented nausea, eight constipation, six local skin reactions, three vomiting and somnolence, and two patients experienced dizziness. Four patients (6.9%) stopped BTDS due to adverse reactions. Conclusions: BTDS is an effective and safe alternative for the treatment of patients with severe post-traumatic pain, reducing the intensity of pain and improving functional capacity and quality of sleep.

Is buprenorphine transdermal patch equally safe and effective in younger and elderly patients with osteoarthritis-related pain? Results of an age-group controlled study

OBJECTIVE

A recent pharmacokinetic study with buprenorphine transdermal patches showed similar systemic exposures of buprenorphine in subjects aged ≥75 and 50-60 years. The current prospective, open-label study aimed to verify this in a clinical setting by evaluating efficacy and safety of buprenorphine patches in patients with chronic osteoarthritis (OA) pain.

METHODS

Patients with chronic, moderate to severe osteoarthritic pain (hip and/or knee) were enrolled: 50-60 years (younger group, N = 65) and ≥75 years (elderly group, N = 57). After 2 weeks on paracetamol only, patients received buprenorphine patches (5-40 µg/h) for 12 weeks. Paracetamol rescue was provided. Primary endpoint was the Box-Scale-11 (BS-11) score for pain on average over the last week. WOMAC OA Index, EQ-5D, Patients' and Investigators' Global Assessment of Pain Relief, rescue medication use, sleep disturbance and quality of sleep were secondary efficacy endpoints.

RESULTS

Both groups showed a statistically significant (p < 0.0001) and clinically relevant change from baseline to last visit in BS-11 score, with no significant difference between groups. The least squares (LS) mean change from baseline was 2.20 in elderly and 1.87 in younger patients, with an age group difference of 0.33 (95% CI: -0.42, 1.07). Non-inferiority of the elderly versus the younger group was shown. Both age groups showed a significant improvement in WOMAC total score, patients' overall health state (EQ-5D visual analogue scale) and sleep quality, and a significant reduction in rescue use and nights woken due to pain, with no significant differences between groups. Elderly patients tolerated buprenorphine patches at least as well as younger patients.

CONCLUSIONS

Efficacy and tolerability of buprenorphine patches was demonstrated in chronic pain patients, regardless of age, supporting the conclusion that no age-related dose adjustment of transdermal buprenorphine is needed. A study limitation is lack of active control but no other opioid was appropriate in elderly patients or this indication.

Predicting medication persistence to buprenorphine transdermal system

OBJECTIVES

Persistence, the duration a patient remains on therapy, in chronic, symptomatic conditions plays an important role in therapy effectiveness. Understanding the duration and patient factors associated with prescribed medication persistence is, therefore, an important step toward better treatment and health outcomes for patients. In the following study, an analysis of such factors associated with buprenorphine transdermal system (BTDS) persistence was conducted utilizing a large US private practitioner and pharmacy claims database and is herein reported.

METHODS

Patients aged ≥ 18 years initiating BTDS during January 1, 2011-November 30, 2011 were identified in the IMS Private Practitioner Medical Claims and Pharmacy Claims databases. An index date was defined as the first prescription of BTDS during the studied interval. During the preindex period, Charlson Comorbidity Index (CCI), chronic pain-related conditions, and prior medication use were assessed. Concomitant medications and various treatment patterns (eg, last dose strength and dose adjustments) were assessed in the postindex 6-month period. Persistence was measured as the duration of BTDS from initiation to the 1st >28-day refill gap in the postindex 6-month period. Descriptive statistical and survival analysis was used to assess the predictors of BTDS persistence.

RESULTS

During the study period, 10,457 patients newly treated with BTDS were identified. Patients' mean (± SD) age was 54.5 (± 15.2) years; 69.9% were women, and the mean (± SD) CCI was 1 (± 1.4). Utilizing a hierarchical approach, patients were separated into different cohorts based on the initial analgesic prescription identified during postindex period with 91.7%, 34.7%, and 59.0% of the patients using opioids, NSAIDs and adjuvant analgesics, respectively. Multivariate regression analyses showed that patients with prior opioid and adjuvant analgesic use were 21% and 5% less likely to discontinue BTDS (P < 0.05), respectively, as compared to patients not using these agents. Patients with concomitant use of adjuvant analgesics were 15% less likely to discontinue therapy (P < 0.05) as compared to patients without concomitant use of these agents. Long-term BTDS persistence was also observed in patients who had a dose change or a last dose strength >5 mcg/hour. Sensitivity analyses for those with 30-day prior opioid use and patients with ≥ 2 claims of BTDS confirmed these findings.

CONCLUSIONS

Prior and concomitant use of adjuvant analgesics, prior use of opioids, and dose adjustments were associated with significantly longer persistence among patients initiating BTDS. The results suggest that patients are less likely to discontinue BTDS early if practitioners account for prior treatment history and dose titration.

Medication pain management in the elderly: unique and underutilized analgesic treatment options

BACKGROUND

By 2030, the US population of adults aged ≥65 years will increase by >80%, and these adults will account for nearly 20% of the US population. In this population, the decline of multiple physiologic processes and diseases collectively influence treatment options. Physiologic changes, drug-drug interactions resulting from polypharmacy, and drug-disease interactions combine to make elderly patients more sensitive to the adverse events (AEs) associated with medications, all of which must be considered in drug selection.

OBJECTIVE

This article focuses on select underutilized medication options for analgesia that may provide significant advantages in the elderly population above and beyond commonly prescribed conventional choices.

METHODS

We performed a complete review of the literature using the search terms pain management, elderly, opioids, NSAIDs, topical NSAIDs, levorphanol, buprenorphine transdermal, and tapentadol. Databases searched included PubMed, Google Scholar, Ovid, and Athens. Package inserts were utilized for approval dates, indications, and formulations available. We looked at reviews of agents to identify important studies for consideration that searches may have missed. Pharmacology and pharmacokinetic data were taken from randomized trials focusing in this area. Pivotal Phase III trials were utilized for discussion of clinical trial experience and to summarize efficacy and AEs. For purposes of validity, only peer-reviewed literature was included.

RESULTS

There were limited data that specifically outlined analgesic drug selection and highlighted safer alternatives for the elderly patient based on polypharmacy risks, end-organ deterioration, and/or drug choices that presented less risk. We focused on unique opioid alternatives: levorphanol, which offers several therapeutic advantages similar to methadone but without the pharmacokinetic and drug-interaction pitfalls associated with methadone; tapentadol, associated with significantly less gastrointestinal distress and constipation; and transdermal buprenorphine, an agonist/antagonist with less risk for the toxicities associated with conventional opioids and with compliance benefits. Topical NSAIDs are discussed as a viable therapeutic option. Specific attention to a more desirable tolerability profile, including avoidance of drug interactions, end-organ dysfunction, and gastrointestinal bleed with topical NSAID agents versus their oral counterparts is discussed, including the ability to achieve superior tissue levels for appropriately selected inflammatory conditions.

CONCLUSION

It is incumbent that providers consider these options as part of an analgesic armamentarium in an effort to maximize therapeutic benefit and minimize risks in the increasing elderly patient population.

Once-weekly transdermal buprenorphine application results in sustained and consistent steady-state plasma levels

CONTEXT

Transdermal formulations of buprenorphine offer controlled delivery of buprenorphine for sustained analgesic efficacy with reduced adverse events (AEs) compared with the other modes of administration. A buprenorphine transdermal system (BTDS) delivering 5, 10, or 20 mcg/hour for seven days is now marketed in the U.S. as Butrans(®) (Lohmann Therapie-System AG, Andernach Germany), a Schedule III single-entity opioid analgesic indicated for the management of moderate and chronic pain in patients requiring continuous around-the-clock analgesia for an extended period.

OBJECTIVES

This was a randomized open-label study in healthy subjects to characterize the steady-state buprenorphine pharmacokinetics after the delivery of three consecutive seven-day BTDS applications.

METHODS

Thirty-seven subjects were randomized to receive three consecutive BTDS 10 mcg/hour (BTDS 10) patches applied to the deltoid or upper back for seven days each. Blood samples for buprenorphine concentration measurements were taken. Safety was assessed using recorded AEs, clinical laboratory test results, vital signs, pulse oximetry, physical examinations, and electrocardiograms. Patch adhesion assessments were taken.

RESULTS

Analysis of Cmin demonstrated that steady state was reached during the first BTDS 10 application. No significant difference in Cmin was observed across the three applications. Total and peak plasma buprenorphine exposures were similar after each of the seven-day administrations of BTDS.

CONCLUSION

Three consecutive once-weekly applications of BTDS 10 provided consistent and sustained delivery of buprenorphine. Steady-state plasma concentrations were reached within 48 hours of the first application of BTDS 10. Patch adhesion analysis confirmed the appropriateness of the seven-day application period. Overall, BTDS 10 was safe and well tolerated.

Primary care considerations of the pharmacokinetics and clinical use of extended-release opioids in treating patients with chronic noncancer pain

Extended-release (ER) opioid analgesics are associated with prolonged analgesia and greater stability in pain relief compared with immediate-release formulations. Due to the pharmacokinetic (PK) characteristics of ER opioids and additional clinical advantages, the use of ER opioids for patients with moderate-to-severe chronic noncancer pain has increased. Primary care physicians are the major prescribers of opioids and require an in-depth understanding of the risks and benefits of opioid treatment in pain management. With appropriate knowledge of PK profiles and clinical outcomes of commonly prescribed ER opioids, primary care physicians can safely and effectively manage this patient population. In addition, the development of ER opioids with abuse-deterrent features marks an important milestone in potentially reducing abuse and may be factored into the clinical decision-making process. This article provides a comprehensive review of the PK and clinical effects of ER opioids and discusses novel ER opioid formulations that may limit abuse potential.

Buprenorphine 5, 10 and 20 μg/h transdermal patch: a guide to its use in chronic non-malignant pain

Buprenorphine lower-dose (5, 10 and 20 μg/h) transdermal patches, which are administered once every 7 days, are indicated in the management of chronic non-malignant pain. This review focuses on the labelling of this formulation (BuTrans®) in the EU. The analgesic efficacy of transdermal buprenorphine in patients with osteoarthritis of the hip and/or knee has been demonstrated to be equivalent to sublingual buprenorphine, noninferior to prolonged-release tramadol and generally superior to a matching transdermal placebo patch. When used together with regularly scheduled oral paracetamol (acetaminophen), transdermal buprenorphine was noninferior to codeine plus paracetamol. Transdermal buprenorphine has also shown analgesic efficacy in patients with chronic non-malignant pain of various causes.

Buprenorphine 5, 10 and 20 μg/h transdermal patch: a review of its use in the management of chronic non-malignant pain

This article reviews the pharmacology, therapeutic efficacy and tolerability profile of the 7-day lower-dose (5, 10 and 20 μg/h) buprenorphine transdermal patch (BuTrans®, Norspan®) in the management of chronic non-malignant pain, with a focus on European labelling for the drug. Buprenorphine is a semi-synthetic opioid analgesic that acts primarily as a partial agonist at the mu opioid receptor. The transdermal formulation provides continuous delivery of buprenorphine, resulting in relatively consistent plasma drug concentrations throughout the 7-day dosing interval. The analgesic efficacy of transdermal buprenorphine in patients with osteoarthritis of the hip and/or knee has been demonstrated in several randomized controlled trials, which have shown the formulation to be equivalent to sublingual buprenorphine, noninferior to prolonged-release tramadol tablets, noninferior to codeine plus paracetamol (acetaminophen) combination tablets (when transdermal buprenorphine was used together with regularly scheduled oral paracetamol) and generally superior to a matching transdermal placebo patch. Transdermal buprenorphine was significantly more effective than placebo in reducing chronic low back pain of at least moderate severity in two randomized, double-blind, crossover trials. Other clinical trials, including a randomized, double-blind, maintenance-of-analgesia study, have also demonstrated the analgesic efficacy of transdermal buprenorphine in patients with chronic non-malignant pain of various causes. In general, serious adverse events with transdermal buprenorphine are similar to those for other opioid analgesics. Transdermal buprenorphine has a ceiling effect for respiratory depression, and the main risk is when it is combined with other CNS depressants. The most frequently reported adverse events with transdermal buprenorphine are headache, dizziness, somnolence, constipation, dry mouth, nausea, vomiting, pruritus, erythema, application site pruritus and application site reactions. Transdermal buprenorphine was better tolerated than sublingual buprenorphine in a 7-week, randomized, double-blind trial in patients with osteoarthritis pain. Nevertheless, as with other opioids, persistence with transdermal buprenorphine therapy is difficult for many patients because of adverse events or other reasons. Thus, transdermal buprenorphine has generally demonstrated good efficacy and tolerability in clinical trials in chronic non-malignant pain, providing effective background analgesia as part of pain management strategies for patients with osteoarthritis, low back pain and other persistent pain syndromes of at least moderate severity. It also has favourable pharmacodynamic and pharmacokinetic properties, which have beneficial clinical implications, most notably the convenience of once-weekly administration and no need for dosage adjustments in the elderly or those with compromised renal function, making it an opioid of choice in these patients, and a useful therapeutic option overall in the management of chronic non-malignant pain.

Low-dose transdermal buprenorphine - long-term use and co-medication with other potentially addictive drugs

INTRODUCTION

Recently, low-dose transdermal buprenorphine (LD-TD-BUP) was introduced for treatment of patients with chronic non-malignant pain. The primary aim of this study was to determine the proportion of patients who were prescribed LD-TD-BUP for non-malignant pain who became long-term users. The secondary aim was to determine the proportion of patients who co-medicated with other opioids or benzodiazepines during treatment with LD-TD-BUP.

METHODS

Data were drawn from the Norwegian Prescription Database that covers all prescriptions dispensed at pharmacies to the entire Norwegian population (4.7 million inhabitants). The study population consisted of all patients who were dispensed at least one prescription of LD-TD-BUP from its introduction in November 2005 to 31 December 2008. Patients who were dispensed more than 24 patches (≥ 6 months) were defined as long-term users. Reimbursement codes were used to stratify patients as having cancer pain or non-malignant pain.

RESULTS

Among new users of LD-TD-BUP for non-malignant pain (n = 13,451), only 22% became long-term users, while 44% were only dispensed one prescription. Among long-term users who were opioid naive when LD-TD-BUP was initiated, 43% co-medicated with other opioids or benzodiazepines, compared with 82% of those who previously had used opioids.

CONCLUSION

Three years after introduction, 0.4% of the Norwegian population had been dispensed LD-TD-BUP. Only one-fifth had become long-term users. Those who used opioids before the first dispension of LD-TD-BUP co-medicated with other potentially addictive drugs to a much higher degree compared with those who were opioid naive.

Buprenorphine and buprenorphine/naloxone diversion, misuse, and illicit use: an international review

The diversion, misuse, and non-medically supervised use of buprenorphine and buprenorphine/naloxone by opioid users are reviewed. Buprenorphine and buprenorphine/naloxone are used globally as opioid analgesics and in the treatment of opioid dependency. Diversion of buprenorphine and buprenorphine/naloxone represents a complex medical and social issue, and has been widely documented in various geographical regions throughout the world. We first discuss the clinical properties of buprenorphine and its abuse potential. Second, we discuss its diversion and illicit use on an international level, as well as motivations for those activities. Third, we examine the medical risks and benefits of buprenorphine's non-medically supervised use and misuse. These risks and benefits include the effect of buprenorphine's use on HIV risk and the risk of its concomitant use with other medications and drugs of abuse. Finally, we discuss the implications of diversion, misuse, and non-medically supervised use (including potential measures to address issues of diversion); and potential areas for further research.

Buprenorphine Transdermal System

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