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

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.

Triglyceride-Mimetic Prodrugs of Buprenorphine Enhance Oral Bioavailability via Promotion of Lymphatic Transport

Buprenorphine (BUP) is a potent opioid analgesic that is widely used for severe pain management and opioid replacement therapy. The oral bioavailability of BUP, however, is significantly limited by first-pass metabolism. Previous studies have shown that triglyceride (TG) mimetic prodrugs of the steroid hormone testosterone circumvent first-pass metabolism by directing drug transport through the intestinal lymphatics, bypassing the liver. The current study expanded this prodrug strategy to BUP. Here different self-immolative (SI) linkers were evaluated to conjugate BUP to the 2 position of the TG backbone via the phenol group on BUP. The SI linkers were designed to promote drug release in plasma. Lipolysis of the prodrug in the intestinal tract was examined via incubation with simulated intestinal fluid (SIF), and potential for parent drug liberation in the systemic circulation was evaluated via incubation in rat plasma. Lymphatic transport and bioavailability studies were subsequently conducted in mesenteric lymph duct or carotid artery-cannulated rats, respectively. TG prodrug derivatives were efficiently transported into the lymphatics (up to 45% of the dose in anaesthetised rats, vs. less than 0.1% for BUP). Incorporation of the SI linkers facilitated BUP release from the prodrugs in the plasma and in concert with high lymphatic transport led to a marked enhancement in oral bioavailability (up to 22-fold) compared to BUP alone. These data suggest the potential to develop an orally bioavailable BUP product which may have advantages with respect to patient preference when compared to current sublingual, transdermal patch or parenteral formulations.

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.

Exploration into the opinions of patients with HIV, healthcare professionals and the lay public of the use of microneedles in clinical practice: highlighting the translational potential for their role in HIV infection

Poor adherence to oral antiretroviral therapy (ART) remains an important challenge in the treatment of HIV. Microneedles (MN) potentially could offer a non-invasive long-acting (LA) delivery approach, avoiding the need for daily dosing of ART. However, this claim has yet to be explored amongst its potential end-users. The aim of this mixed methods study was to investigate the perspectives from various end-users surrounding the translation of MN technology to general clinical practice, with a particular focus on delivery of ART. Quantitative postal questionnaires were distributed amongst healthcare professionals (HCPs) and the lay public (LP). A total of 208 responses were obtained (HCP, 69; LP, 139), with a completion rate of 34.7%. The consensus on MN technology was positive from both demographics (HCP, 97.1%; LP, 98.6%), with further strong support of postulated MN use within HIV (HCP, 97.1%; LP, 98.6%). Qualitative focus groups were employed to investigate in-depth, the perspectives of 12 patients with HIV. Again, consensus on MN technology was positive, highlighting benefits pertinent to HIV, including discreet self-application and potential sustained release thus avoiding daily oral ART and associated side effects. Patient concerns focused on the need for varied MN dosing schedules and a reluctance to change from established ART. The findings of this study provide an initial indication of MN acceptability, particularly for use within HIV, from various end-user demographics. Furthermore, concerns raised advocate the importance of continued translational research in this area and should act as motivators for those in MN development to ensure a patient-centred MN product is delivered.

The utilization of buprenorphine in chronic pain

Reclassification of chronic pain as a disease may be helpful because patients with chronic pain require significant treatment and rehabilitation with a clear diagnosis. This can help address critical factors including suffering, quality of life, participation, and with family and social life, which continue to become more important in evaluating the quality of the health care we give our patients today. During the past decade of the opioid epidemic, methadone was the primary treatment for opioid addiction until buprenorphine was approved. Buprenorphine's high-affinity partial agonist properties make it a good alternative to methadone due to lower abuse potential and safer adverse effect profile while maintaining significant efficacy. Expanded out-patient prescribing options have allowed physician and physician extenders such as physician assistants and nurse practitioners to treat these patients that otherwise would have been required to utilize methadone. With unique pharmacological properties, buprenorphine is a safe and effective analgesic for chronic pain. The literature for buprenorphine shows great potential for its utilization in the treatment of chronic pain.

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.

Lost cost savings to the NHS in England due to the delayed entry of multiple generic low-dose transdermal buprenorphine: a case scenario analysis

OBJECTIVE

Originator pharmaceutical companies prolonging the patent of a medicine prevents rivals' entry to the market and competition. As the entry of generic alternatives usually results in price reduction, any delay in their entry potentially deprives the National Health Service (NHS) of much-needed savings. This study estimates the potential cost savings lost to the NHS as a result of delayed entry of generic low-dose buprenorphine (LDTB) patches in England.

DESIGN

Two case scenarios were modelled to determine the savings from the entry of generic LDTB Butec only between February and August 2016 and the potential savings which could have been achieved if all generic LDTB patches had entered the market at the same time.

SETTING

The volume of utilisation of branded and generic LDTB in UK primary care was derived from the NHS business services authority website for prescriptions dispensed between February 2015 and January 2018.

MAIN OUTCOME MEASURES

Cost savings associated with the entry of generic LDTB.

RESULTS

The cumulative cost savings from the introduction of Butec alone was £0.7 ($0.92) million. The model predicted that if all generic buprenorphine entered the market at the same time with Butec, they could have been achieved a £1.2 ($1.57) million saving. This means that approximately £0.5 ($0.65) million savings was lost to the NHS over the 6-month time period.

CONCLUSIONS

The entry of Butec was associated with cost savings. We estimated that more cost savings could have been achieved if other generic LDTB patches had entered the market at the same time to drive competition between rivals. Patent protection strategies which delayed the entry of multiple generics were responsible for the reduced cost savings to the NHS in England.

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 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.

The switch from buprenorphine to tapentadol: is it worth?

Opioid analgesia continues to be the primary pharmacologic intervention for managing acute pain and malignant pain in both hospitalized and ambulatory patients. The increasing use of opioids in chronic nonmalignant pain is more problematic. Opioid treatment is complicated with the risks raised by adverse effects, especially cognitive disturbance, respiratory depression but also the risk of tolerance, opioid abuse and drug-disease interactions. Despite the growing number of available opioids within the last years, adequate trials of opioid rotation are lacking and most of the information is anecdotal. This article reviews the clinical evidence surrounding the switch from transdermal buprenorphine to tapentadol in malignant and non-malignant pain. Tapentadol acts on both the μ-opioid receptors (MOR) and on the neuronal reuptake of noradrenaline with a limited usefulness in acute pain management while buprenorphine is a mixed agonist-antagonist, and both present some advantages over other opioids. Both drugs show particular pharmacodynamic and pharmacokinetic properties which reduce the risks of development of tolerance, opioid abuse, diversion and determine fewer hormone changes than the "classical opioids" making these opioids more attractive than other opioids in long term opioid treatment. However, in the absence of powered clinical trials, the evidence to support the method used for transdermal buprenorphine rotation to tapentadol is weak.

A Phase I study of the pharmacokinetics, safety and tolerability of a novel tocopheryl phosphate mixture/oxymorphone transdermal patch system

AIM

Characterize the pharmacokinetic profile and tolerability of two tocopheryl phosphate mixture/oxymorphone patch formulations in healthy subjects, and the active metabolite (6-OH-oxymorphone).

MATERIALS & METHODS

Fifteen participants received a single application of oxymorphone patches +/- capsaicin for 72 h and were crossed-over for another 72 h.

RESULTS

Plasma oxymorphone was detected approximately 7 h and 6-OH-oxymorphone after approximately 18-19 h postapplication of both formulations, respectively. For oxymorphone, median t_max was 24 h, and C_max/C_min ratio was approximately 2.4. The most frequently reported treatment-related adverse event was application site reaction, mainly with capsaicin formulation.

CONCLUSION

Tocopheryl phosphate mixture/oxymorphone transdermal patches can successfully deliver therapeutic amounts of oxymorphone in a sustained manner over 72 h and are well tolerated. ANZCTR registration number: ACTRN12614000613606.

Comparative study of the efficacy of transdermal buprenorphine patches and prolonged-release tramadol tablets for postoperative pain control after spinal fusion surgery: a prospective, randomized controlled non-inferiority trial

PURPOSE

To compare the efficacy of a transdermal buprenorphine patch (5, 10, 15, and 20 μg/h) with that of oral tramadol (150, 200, 250, and 300 mg) for postoperative pain control after single level spinal fusion surgery.

METHODS

The present study (ClinicalTrials.gov, number NCT02416804) was a prospective, randomized controlled non-inferiority trial designed to determine the efficacy of buprenorphine TDS for alleviating postoperative pain following patient controlled analgesia (PCA) in persons underwent a single level posterior lumbar interbody fusion surgery through 1:1 allocation. The primary outcome was the Visual Analog Pain Scale (VAS) score for postoperative back pain at 7 days after surgery. The non-inferior margin of the VAS was set at δ = 1.5 points.

RESULTS

The VAS score (primary outcome) for postoperative back pain at 7 days after surgery in the Buprenorphine group was not inferior compared to the Tramadol group. The overall changes in VAS scores for postoperative pain during follow-up assessments over a 2-week period did not differ between both groups. However, the VAS scores for postoperative pain significantly improved with time after surgery in both groups. The patterns of changes in the VAS scores for postoperative pain during the follow-up period were not significantly different between the both groups.

CONCLUSIONS

The efficacy of buprenorphine TDS was not inferior to that of oral tramadol medication for alleviating postoperative pain in the subacute period from 72 h after surgery, following PCA administration. In addition, adverse events were similar between both groups.

Pharmacotherapy of Pain in the Older Population: The Place of Opioids

Pain is a common symptom in older people. It is possible that pain is underreported in older persons due to an incorrect belief that it is an inevitable part of aging. Opioid analgesics are potent medications, with confirmed efficacy for the treatment of moderate to severe pain. These drugs are commonly used in older persons. However, there is insufficient evidence regarding safety of opioids in older patients. One of the reasons for this is the lack of randomized, controlled clinical trials. People of advanced age often have comorbidites and use other prescription drugs, as well as over-the-counter (OTC) compounds, thus making them more suceptible to the risk of interactions with opioids. Significant pharmacokinetic and pharmacodynamic changes that occur with advancing age increase the risk of adverse effects of opioids. There are also some discrepancies between guidelines, which recommend the use of lower doses of opioids in older patients, and the findings in the literature which suggest that pain is often undertreated in this age group. It seems that there are significant variations in the tolerability of different opioid analgesics in older people. Morphine, fentanyl, oxycodone, and buprenorphine are still the preferred evidence-based choices for add-on opioid therapy for these patients. However, the safety and efficacy of other opioids in older patients, especially if comorbidities and polypharmacy are present, is still questionable. This review addresses the most important aspects of the use of opioids in older persons, focusing on pharmacokinetics, pharmacodynamics, adverse effects, and interactions.

Marketed New Drug Delivery Systems for Opioid Agonists/Antagonists Administration: A Rapid Overview

Novel drug delivery systems for controlled-release of opioid agonists as a long time painkillers or opioid antagonists for opium, heroin, and alcohol addiction are under development or in clinical use today. In this article, the field of "new drug delivery systems" is momentarily reviewed from the viewpoint of the marketed opioid agonists/antagonists dosage forms today.