Abstract Buprenorphine was not used widely in clinical practice over many years, mainly due to analgesic potency and clinical safety concerns based on misinterpreted animal data. Contrary to previous ...concerns, however, no analgesic ceiling effect and no antagonism of combined pure μ-opioid receptor agonists is seen within the therapeutic dose range. In recent studies, buprenorphine could be effectively and safely combined with full μ-agonists, and switching between buprenorphine and another opioid provided comparable pain relief based on equianalgesic doses. Moreover, buprenorphine exerts an antihyperalgesic effect, which is due—at least in part—to antagonistic activity at κ-opioid receptors. Buprenorphine pharmacokinetics are not altered by advanced age or renal dysfunction. In addition, the risk of respiratory depression is lower than with other opioids including morphine, hydromorphone, methadone and fentanyl. Unlike morphine and fentanyl, there is no immunosuppressive activity with buprenorphine at therapeutic analgesic doses. Transdermal buprenorphine has significantly improved the clinical use of the drug, providing continuous buprenorphine release for up to 96 h. In clinical trials, patients receiving transdermal buprenorphine experienced significantly greater pain relief, better sleep, and a reduced need for rescue therapy, compared to placebo. Large-scale post-marketing studies have confirmed the effectiveness of transdermal buprenorphine in treating moderate-to-severe cancer and non-cancer pain including neuropathic syndromes. Finally, the comparably low incidence of CNS adverse events and constipation, and the possibility of use in severe renal dysfunction without a need for dose adjustment make buprenorphine well suited for chronic pain management in at-risk patients, such as diabetics, elderly or renally impaired individuals including those requiring haemodialysis.
Neuropathic pain (NP) is an enormous burden for patients, caregivers and society. NP is a pain state that may develop after injury of the peripheral or central nervous system because of a wide range ...of diseases and traumas. A NP symptom component can be found also in several types of chronic pain. Many NP patients are substantially disabled for years. Due to its chronicity, severity and unpredictability, NP is difficult to treat. Tapentadol is a central-acting oral analgesic with combined opioid and noradrenergic properties, which make it potentially suitable for a wide range of pain conditions, particularly whenever a NP component is present or cannot be excluded. In randomized controlled trials, tapentadol has proved to be effective in relieving NP in diabetic peripheral neuropathy and in chronic low back pain. In observational studies, tapentadol reduced NP in chemotherapy-induced peripheral neuropathies, blood and solid cancers, and the NP component in neck pain and Parkinson's disease. This narrative review aims to provide clinicians with a broad overview of tapentadol effects on NP.
Thanks to the progress in early diagnosis and treatment of cancer, the life expectancy of cancer patients has now increased. Patients are, therefore, more likely to experience their individual cancer ...pain as a chronic pain. As a consequence, long-term treatment of cancer-related pain and oncological therapy-related pain are a major need for all patients and a challenge to all healthcare professionals. Tapentadol is a centrally acting analgesic drug characterized by two synergistic mechanisms of action, since it acts at the µ-opioid receptor (MOR) and inhibits noradrenalin re-uptake (NRI). Therefore, tapentadol has been considered the first of a new class of drugs, MOR-NRI. Tapentadol has been tested in different populations of cancer patients (opioid-naive and -pretreated), such as those with pain of mixed etiology, patients with pain from hematological malignancies and patients experiencing pain conditions due to anticancer treatment. According to available evidence, tapentadol prolonged release was well tolerated and effective in cancer pain patients. In randomized, double-blind and active-controlled trials it proved non-inferior to standard opioids like morphine or oxycodone in the management of moderate-to-severe cancer pain, both in opioid-naive and in opioid-pretreated patients. The good analgesic efficacy may be partly due to the action of tapentadol on neuropathic pain components. Together with the low rate of gastrointestinal adverse effects and the overall favorable safety profile, tapentadol can be considered a good option in cancer pain patients, who can suffer frequently from nausea, vomiting, constipation or other events that further reduce their quality of life.
Cannabinoid-induced analgesia was shown in animal studies of acute inflammatory and neuropathic pain. In humans, controlled clinical trials with Delta-tetrahydrocannabinol or other cannabinoids ...demonstrated analgesic efficacy in chronic pain syndromes, whereas the data in acute pain were less conclusive. Therefore, the aim of this study was to investigate the effects of oral cannabis extract in two different human models of acute inflammatory pain and hyperalgesia.
The authors conducted a double-blind, crossover study in 18 healthy female volunteers. Capsules containing Delta-tetrahydrocannabinol-standardized cannabis extract or active placebo were orally administered. A circular sunburn spot was induced at one upper leg. Heat and electrical pain thresholds were determined at the erythema, the area of secondary hyperalgesia, and the contralateral leg. Intradermal capsaicin-evoked pain and areas of flare and secondary hyperalgesia were measured. Primary outcome parameters were heat pain thresholds in the sunburn erythema and the capsaicin-evoked area of secondary hyperalgesia. Secondary measures were electrical pain thresholds, sunburn-induced secondary hyperalgesia, and capsaicin-induced pain.
Cannabis extract did not affect heat pain thresholds in the sunburn model. Electrical thresholds (250 Hz) were significantly lower compared with baseline and placebo. In the capsaicin model, the area of secondary hyperalgesia, flare, and spontaneous pain were not altered.
To conclude, no analgesic or antihyperalgesic activity of cannabis extract was found in the experiments. Moreover, the results even point to the development of a hyperalgesic state under cannabinoids. Together with previous data, the current results suggest that cannabinoids are not effective analgesics for the treatment of acute nociceptive pain in humans.
ObjectivesUnrelieved pain is a substantial public health concern necessitating improvements in medical education. The Advancing the Provision of Pain Education and Learning (APPEAL) study aimed to ...determine current levels and methods of undergraduate pain medicine education in Europe.Design and methodsUsing a cross-sectional design, publicly available curriculum information was sought from all medical schools in 15 representative European countries in 2012–2013. Descriptive analyses were performed on: the provision of pain teaching in dedicated pain modules, other modules or within the broader curriculum; whether pain teaching was compulsory or elective; the number of hours/credits spent teaching pain; pain topics; and teaching and assessment methods.ResultsCurriculum elements were publicly available from 242 of 249 identified schools (97%). In 55% (133/242) of schools, pain was taught only within compulsory non-pain-specific modules. The next most common approaches were for pain teaching to be provided wholly or in part via a dedicated pain module (74/242; 31%) or via a vertical or integrated approach to teaching through the broader curriculum, rather than within any specific module (17/242; 7%). The curricula of 17/242 schools (7%) showed no evidence of any pain teaching. Dedicated pain modules were most common in France (27/31 schools; 87%). Excluding France, only 22% (47/211 schools) provided a dedicated pain module and in only 9% (18/211) was this compulsory. Overall, the median number of hours spent teaching pain was 12.0 (range 4–56.0 h; IQR: 12.0) for compulsory dedicated pain modules and 9.0 (range 1.0–60.0 h; IQR: 10.5) for other compulsory (non-pain specific) modules. Pain medicine was principally taught in classrooms and assessed by conventional examinations. There was substantial international variation throughout.ConclusionsDocumented pain teaching in many European medical schools falls far short of what might be expected given the prevalence and public health burden of pain.
BackgroundPainful knee osteoarthritis (KOA) is common, pharmacological treatment, however, is often hampered by limited tolerability. Cannabidiol, which preclinically showed anti-inflammatory, ...analgesic activity, could supplement established analgesics, but robust clinical trials are lacking. The aim of our study was to investigate the effects of oral high-dose CBD administered over 8 weeks on pain, function and patient global assessment as an add-on to continued paracetamol in chronic symptomatic KOA.MethodsProspective, randomized, placebo-controlled, double-blind, parallel-group study. Single center, Outpatient Clinic, Department of Special Anaesthesia and Pain Therapy at Medical University of Vienna, Austria. Eligibility criteria included: age: 18-98 years; painful KOA; score ≥5 on the pain subscale of the Western Ontario and McMasters Universities Osteoarthritis (WOMAC) Index; KOA confirmed by imaging. Participants were on continued dosage of paracetamol 3 g/d and randomly assigned by web-based software 1:1 to oral cannabidiol 600 mg/d (n = 43) or placebo (n = 43). Study period: 8 weeks. Primary outcome: Change in WOMAC pain subscale scores (0 = no pain, 10 = worst possible pain) from baseline to week 8 of treatment. Trial Registration: ClinicalTrials.gov Identifier: NCT04607603. Trial is completed.FindingsThe trial was conducted from October 1, 2020 to March 29, 2022. 159 patients screened, 86 randomized. Among 86 participants (mean age, 62.8 SD 20.3 years; 60 females 69.8%), 58 (67.4%) completed the trial. Mean baseline WOMAC pain subscale was 6.0 ± 1.1. Analysis: Intention-to-treat principal. Mean reduction in WOMAC pain subscale was 2.5 (95% CI: 1.8-3.3) in the cannabidiol group and 2.4 (95% CI: 1.7-3.2) in the placebo group with no significant group difference (p = 0.80). Adverse events were significantly more frequent with cannabidiol (cannabidiol: 135 56%; placebo: 105 44%) (p = 0.008). Rise above baseline of liver aminotransferases and gamma-glutamyltransferase was significantly more common in the cannabidiol (n = 15) than the placebo group (n = 5) (p = 0.02).InterpretationIn KOA patients, oral high-dose add-on cannabidiol had no additional analgesic effect compared to adding placebo to continued paracetamol. Our results do not support the use of cannabidiol as an analgesic supplement in KOA.FundingTrigal Pharma GmbH.
Tapentadol prolonged release (PR) is effective and well tolerated for chronic osteoarthritis, low back, and diabetic peripheral neuropathic pain.
To evaluate the efficacy and tolerability of ...tapentadol PR compared with placebo and morphine controlled release (CR) for managing moderate to severe chronic malignant tumor-related pain.
Randomized-withdrawal, parallel group, active- and placebo-controlled, double-blind phase 3 study (NCT00472303).
Primary, secondary, and tertiary care settings in 16 countries.
Eligible patients (pain intensity ≥ 5 11-point numerical rating scale on prior analgesics) were randomized (2:1) and titrated to their optimal dose of tapentadol PR (100-250 mg bid) or morphine sulfate CR (40-100 mg bid) over 2 weeks. Morphine sulfate immediate release 10 mg was permitted as needed for rescue medication (no maximum dose). Patients who completed titration and, during the last 3 days of titration, had mean pain intensity < 5 (based on twice-daily ratings) and mean rescue medication use = 20 mg/day continued into a 4-week maintenance period; patients who received morphine CR during titration continued taking morphine CR, and those who received tapentadol PR were re-randomized (1:1) to tapentadol PR or placebo bid. Response during maintenance (primary efficacy endpoint) was defined as having: (1) completed the maintenance period, (2) a mean pain intensity < 5 during maintenance, and (3) used an average of = 20 mg/day of rescue medication during maintenance. Response at the end of titration was defined similarly, with pain intensity and rescue medication averages based on the last 3 days of titration.
Of 622 patients screened, 496 were randomized, treated during titration, and evaluable for safety; 327 were re-randomized, treated during maintenance, and evaluable for safety; and 325 were evaluable for efficacy. The adjusted responder rate estimate during maintenance (logistic regression adjusting for treatment group, pooled center, and pain intensity at start of maintenance) was significantly higher with tapentadol PR (64.3%) than with placebo (47.1%; odds ratio (OR), 2.02 95% confidence interval (CI), 1.12 - 3.65; P = 0.02). Based on responder rates at the end of titration, tapentadol PR (76.0% 174/229) was non-inferior to morphine CR (83.0% 83/100). The lower limit of the 95% CI for the between-groups difference (-15.5%) was within the pre-specified 20% non-inferiority margin. During titration, incidences of treatment-emergent adverse events (TEAEs) were 50.0% (169/338) with tapentadol PR and 63.9% (101/158) with morphine CR; incidences of nausea, vomiting, and dry mouth were lower with tapentadol PR than with morphine CR. During maintenance, incidences of TEAEs were 56.3% (63/112), 62.3% (66/106), and 62.4% (68/109) with placebo, tapentadol PR, and morphine CR, respectively.
Statistical comparisons between tapentadol PR and morphine CR were limited to descriptive statistics during the maintenance period because of the pre-selection of responders to tapentadol PR or morphine CR during titration.
Results obtained during maintenance indicate that tapentadol PR (100-250 mg bid) is effective compared with placebo for managing moderate to severe chronic malignant tumor-related pain. Based on results obtained during titration, tapentadol PR provides comparable efficacy to that of morphine sulfate CR (40-100 mg bid), but is associated with better gastrointestinal tolerability.
Abstract
Objective:
This open-label, phase 3b study evaluated the effectiveness and tolerability of tapentadol prolonged release and tapentadol immediate release (for acute pain episodes) for severe, ...chronic low back pain with or without a neuropathic pain component that was inadequately managed in patients taking World Health Organization (WHO) Step I or II analgesics or who were not regularly treated with analgesics.
Research design and methods:
Average baseline pain intensity was greater than 5 (11-point numerical rating scale-3 NRS-3; 3-day average pain intensity) with WHO Step I or II analgesics and greater than 6 with no regular analgesic regimen. WHO Step II analgesics were discontinued before starting study treatment; WHO Step I analgesics or co-analgesics were continued at the same dose. Patients received tapentadol prolonged release (50-250 mg bid) during a 5-week titration and 7-week maintenance period. Tapentadol immediate release was permitted for acute pain episodes (tapentadol prolonged release and immediate release maximum combined dose, 500 mg/day). The painDETECT questionnaire was used to define subsets of patients based on the probability of a neuropathic pain component to their low back pain as 'negative', 'unclear', or 'positive'.
Clinical trial registration: NCT00983385.
Main outcome measure:
The primary endpoint was the change from baseline to week 6 in average pain intensity (NRS-3), using the last observation carried forward to impute missing scores.
Results:
In the painDETECT negative (n = 49) and unclear/positive (n = 126) subsets, respectively, mean (SD) changes in pain intensity from baseline to week 6 were −2.4 (2.18) and −3.0 (2.07; both p < 0.0001). Among patients who had not received prior WHO Step II treatment, lower doses of tapentadol prolonged release were generally required with increasing likelihood of a neuropathic pain component. Based on the painDETECT questionnaire and the Neuropathic Pain Symptom Inventory (NPSI), tapentadol prolonged release treatment was also associated with significant improvements in neuropathic pain symptoms, with decreases in the number of pain attacks and the duration of spontaneous pain in the last 24 hours in patients with low back pain with a neuropathic pain component (painDETECT unclear or positive score at baseline or screening). The most common treatment-emergent adverse events (incidence 10%, n = 176) were nausea, dizziness, headache, dry mouth, fatigue, constipation, diarrhea, nasopharyngitis, and somnolence.
Conclusions:
Tapentadol prolonged release was well tolerated and effective for managing severe, chronic low back pain with or without a neuropathic pain component.
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