New therapeutic principles for adverse effects on upper and lower gastrointestinal tract in patients treated with opioid analgesics

Opioid-induced constipation

Opioid-induced constipation is described, including features, mechanism, and management of the disorder. The role of various categories of laxatives including suppositories and the use of a peripherally acting μ-opioid receptor antagonist are discussed.

The impact of chronic pain-European patients' perspective over 12 months

Background and methods Pain Study Tracking Ongoing Responses for a Year (PainSTORY) is a longitudinal study generating some quantitative and limited qualitative data concerning the experiences of individual patients with non-malignant chronic pain. Research was conducted across 13 European countries and a total of 294 patients completed the full evaluation process over 12 months. Adult patients (>18 years old) scoring >4 on an 11-point numeric pain rating scale (NRS-11) for most days during an average week were eligible. Four waves of interviews (W1-W4) were conducted over 12 months and information was recorded regarding pain levels, the impact of pain, pain treatment and treatment-associated side effects. Results At 3 months, 95% of respondents rated their worst pain level over the past week as ≥4. Most respondents had felt this pain level for ≥1 year, with 47% of patients reporting NRS-11 scores of 8-10 for >2 years. At 12 months, 93% of respondents still rated their worst pain level over the past week as ≥4. The overall net percentage of respondents with ≥4 pain intensity did not change substantially over 12 months of follow up. However, 40% (119/294) of patients felt their current pain level increased and 41% (121/294) felt their current pain level decreased during this time, with just 18% (53/294) of respondents reporting no change (1% of respondents not stated). At 3 months, 30% of respondents reported being managed by a pain specialist within the last 3 months, decreasing to 13% 9-12 months later. Patients were typically taking a combination of prescribed and non-prescribed medications; approximately 10% at W1 and 14% at 12 months were prescribed a strong opioid. Among those whose current pain level decreased over the year, a slightly lower proportion of patients were taking prescription medication (78%) at 12 months than in either the group with no change to their current pain level (85%), or the group whose pain level increased over the 12 month period (87%). Pain negatively affected quality of life, with respondents reporting difficulties with daily activities, including sleeping, walking, family and social interaction. Approximately half of respondents taking prescription medication reported suffering from 'constipation and associated symptoms'. In spite of no change in pain intensity, 51% of patients were happy with their pain management at W4. Conclusions The heavy individual and societal burden of uncontrolled chronic pain is demonstrated in this study. This silent epidemic has not attracted the focus of attention that it deserves. Despite the significant negative impact on individual quality of life, patients evolve to a position where they believe that chronic pain is inevitable and untreatable. implications It is clear that there is a real need for a coordinated response by healthcare providers and planners across European countries. Minimum standards of care should be developed and implemented at national level. Healthcare professionals and students of these disciplines must be educated to recognise, assess and manage pain within a reasonable timeframe. Patients who are not responding to standard measures must have rapid and easy access to a comprehensive, inter-disciplinary pain service.

A 6-months, randomised, placebo-controlled evaluation of efficacy and tolerability of a low-dose 7-day buprenorphine transdermal patch in osteoarthritis patients naïve to potent opioids

Objective

Patients with osteoarthritis (OA) pain often have insufficient pain relief from non-opioid analgesics. The aim of this trial was to study efficacy and tolerability of a low dose 7-day buprenorphine transdermal delivery system, added to a NSAID or coxib regimen, in opioid-naïve patients with moderate to severe OA pain.

Methods

A 6 months randomised, double-blind, parallel-group study at 19 centres in Denmark, Finland, Norway, and Sweden, in which OA patients (>40 years) with at least moderate radiographic OA changes and at least moderate pain in a hip and/or knee while on a NSAID or a coxib were randomised to a 7-day buprenorphine patch (n = 100) or an identical placebo patch (n = 99). The initial patch delivered buprenorphine 5 μg/h. This was titrated to 10 or 20 μg/h, as needed. Rescue analgesic was paracetamol 0.5–4 g daily. Statistical analysis of outcome data was mainly with a general linear model, with treatment as factor, the primary joint of osteoarthritis, baseline scores, and season as covariates.

Results

Most patients had OA-radiographic grade II (moderate) or grade III (severe), only 8 in each group had very severe OA (grade IV). The median buprenorphine dose was 10 μg/h. 31 buprenorphine-treated patients and 2 placebo-treated patients withdrew because of side effects. Lack of effect caused 12 placebo-treated and 7 buprenorphine-treated patients to withdraw. The differences in effects between treatments: Daytime pain on movement, recorded every evening on a 0–10 numeric rating scale decreased significantly more (P = 0.029) in the buprenorphine group. Patients’ Global Impression of Change at the end of the double blind period was significantly improved in the buprenorphine group (P = 0.017). The chosen primary effect outcome measure, the Western Ontario and McMaster Universities (WOMAC) OA Index for Pain (P = 0.061), and secondary outcome measures, the WOMAC OA score for functional abilities (P = 0.055), and the WOMAC total score (P = 0.059) indicated more effects from buprenorphine than placebo, but these differences were not statistically significant. In a post-hoc, subgroup analysis with the 16 patients with radiographic grad IV (very severe) excluded, WOMAC OA Index for Pain was significantly (P = 0.039) reduced by buprenorphine, compared with placebo. WOMAC OA score for stiffness and the amount of rescue medication taken did not differ. Sleep disturbance, quality of sleep, and quality of life improved in both groups. Side effects: Typical opioid side effects caused withdrawal at a median of 11 days before completing the 168 days double blind trial in 1/3 of the buprenorphine group. Mostly mild local skin reactions occurred equally often (1/3) in both groups.

Conclusions

Although the 24 hours WOMAC OsteoArthritis Index of pain was not statistically significantly superior to placebo, day-time movement-related pain and patients’ global impression of improvement at the end of the 6-months double blind treatment period were significantly better in patients treated with buprenorphine compared with placebo. Opioid side effects caused 1/3 of the buprenorphine-patients to withdraw before the end of the 6-months double blind study period.

Implications

A low dose 7-days buprenorphine patch at 5–20 μg/h is a possible means of pain relief in about 2/3 of elderly osteoarthritis patients, in whom pain is opioid-sensitive, surgery is not possible, NSAIDs and coxibs are not recommended, and paracetamol in tolerable doses is not effective enough. Vigilant focus on and management of opioid side effects are essential.