A 2-week, multicenter, randomized, double-blind, placebo-controlled, dose-ranging, phase III trial comparing the efficacy of oxymorphone extended release and placebo in adults with pain associated with osteoarthritis of the hip or knee. Treatment of persistent pain associated with osteoarthritis with controlled-release oxycodone tablets in a randomized controlled clinical trial. Double blind randomized placebo control trial of controlled release codeine in the treatment of osteoarthritis of the hip or knee. Oxymorphone extended-release tablets relieve moderate to severe pain and improve physical function in osteoarthritis: results of a randomized, double-blind, placebo- and active-controlled phase III trial. Impact of controlled-release oxycodone on efficacy beliefs and coping efforts among osteoarthritis patients with moderate to severe pain. Transdermal fentanyl for improvement of pain and functioning in osteoarthritis: a randomized, placebo-controlled trial. Adding ultralow-dose naltrexone to oxycodone enhances and prolongs analgesia: a randomized, controlled trial of Oxytrex. Ibuprofen plus codeine, ibuprofen, and placebo in a single- and multidose cross-over comparison for coxarthrosis pain. Efficacy and safety of a once-daily morphine formulation in chronic, moderate-to-severe osteoarthritis pain: results from a randomized, placebo-controlled, double-blind trial and an open-label extension trial. Codeine plus paracetamol versus paracetamol in longer-term treatment of chronic pain due to osteoarthritis of the hip. A randomised, double-blind, multi-centre study.
Oxymorphone extended release (ER) is a tablet formulation of the mu-opioid agonist oxymorphone designed to achieve a low peak-to-trough fluctuation in plasma concentrations over a 12-hour dosing period.
                This study compared the analgesic efficacy, dose response, and tolerability of 3 doses of oxymorphone ER given every 12 hours with those of placebo in patients with pain related to osteoarthritis (OA) of the hip or knee.
                This was a 2-week, multicenter, randomized, double-blind, placebo-controlled, dose-ranging, Phase III trial. Patients with OA of the hip or knee who were receiving an opioid medication for chronic, moderate to severe pain or who were judged by the investigator to have received suboptimal analgesia with nonopioid analgesics entered a 2- to 7-day washout of analgesic medication. When pain in the index joint was >40 mm on a 100-mm visual analog scale (VAS), patients were randomized to receive 1 of 4 regimens: oxymorphone ER 10 mg q12h during weeks 1 and 2; oxymorphone ER 20 mg q12h in week 1 and 40 mg q12h in week 2; oxymorphone ER 20 mg q12h in week 1 and 50 mg q12h in week 2; or placebo q12h during weeks 1 and 2. The primary end point was the change in VAS score for arthritis pain intensity. Other assessments included the Western Ontario and McMaster Universities (WOMAC) OA Index subscales for pain, stiffness, and physical function and the composite index; the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) physical health component summary (PCS) score; the Chronic Pain Sleep Inventory (CPSI) score; vital signs; clinical laboratory parameters; and adverse events (AEs). AEs were recorded at each clinic visit.
                Three hundred seventy patients were randomized to treatment (95 oxymorphone ER 10 mg, 93 oxymorphone ER 40 mg, 91 oxymorphone ER 50 mg, and 91 placebo), and 198 completed the study. Least squares mean changes from baseline in the VAS arthritis pain intensity score were -21, -28, -29, and -17 mm in the oxymorphone ER 10, 40, and 50 mg and placebo groups, respectively (P = 0.002, modified Tukey linear trend test). Oxymorphone ER 40 and 50 mg produced significant improvements from baseline compared with placebo in the WOMAC subscale scores for pain (least squares mean change: -85.1, -108.0, and -42.5, respectively; P < or = 0.025 for 40 mg, P < or = 0.001 for 50 mg), stiffness (-40.5, -48.1, and -17.0; both, P < or = 0.001), and physical function (-256.8, -310.8, and -116.5; P < or = 0.01 and P < or = 0.001, respectively); the SF-36 PCS score (4.6, 3.6, and -0.1; P < 0.001); and the CPSI score (-21.2, -22.2, and -10.7; P < 0.05). The 10-mg dose also was associated with significant improvements compared with placebo in the WOMAC pain (-83.6; P < or = 0.025) and physical function subscales (-232.9; P < or = 0.025) and the SF-36 PCS score (3.9; P < 0.001). The most frequently reported AEs (> or =5% of patients) in the oxymorphone ER groups were nausea (39.4%), vomiting (23.7%), dizziness (22.6%), constipation (22.2%), somnolence (17.6%), pruritus (16.5%), and headache (15.0%). The majority of AEs with oxymorphone ER were mild or moderate in intensity. Three serious AEs (urinary retention, central nervous system depression, and pancreatitis) were considered possibly or probably related to study medication.
                In these patients with chronic, moderate to severe pain related to OA of the hip or knee, oxymorphone ER administered twice daily for 2 weeks produced dose-related reductions in arthritis pain intensity and improvements in physical function. This study, lasting up to 90 days, was undertaken in patients with osteoarthritis with persistent moderate to severe pain uncontrolled by standard therapy (nonsteroidal anti-inflammatory drugs, acetaminophen, and/or short-acting opioids) to evaluate functional outcomes, as well as efficacy and safety, of controlled-release oxycodone versus placebo.
                One hundred seven patients received either controlled-release oxycodone or placebo every 12 hours in this double blind, randomized, placebo-controlled, parallel-group study. Stable previous regimens of acetaminophen or nonsteroidal anti-inflammatory agents were allowed to continue. Primary efficacy variables included Brief Pain Inventory average pain intensity scores at completion of initial titration, Western Ontario and McMaster Universities Osteoarthritis Index scores at days 30 and 60, and the percentage of patients discontinuing due to inadequate pain control.
                Controlled-release oxycodone was significantly superior to placebo in decreasing average pain intensity and in reducing pain-induced interference with general activity, walking ability (except at day 30), and normal work, as well as mood, sleep, relations with people (at days 60 and 90), and enjoyment in life. Daily functioning, as measured by the Western Ontario and McMaster Universities Osteoarthritis Index, was also significantly improved in the controlled-release oxycodone group. In the placebo group, a significantly greater percentage of patients discontinued due to inadequate pain control. Adverse events were consistent with opioid adverse events, and no safety concerns were noted.
                Treatment with controlled-release oxycodone of patients with osteoarthritis with persistent moderate to severe pain uncontrolled by standard therapy resulted in significant pain control and improvements in physical functioning. Pain is the cardinal feature of osteoarthritis (OA), and with advancing disease there is loss of function and increasing pain even at times of joint rest. Few studies have evaluated the role of opioid analgesics in treating the pain of OA.
                This randomized, double blind, parallel group study compared the efficacy and safety of a 12 hourly controlled release codeine formulation (Codeine Contin) with placebo in patients with chronic pain due to OA of the hips and/or knees. The 4 week treatment period, following an analgesic washout phase of 2-7 days, included weekly clinic evaluations, at which the dose was escalated as appropriate, and daily patient diary completion. Pain (daily), stiffness, and physical function (weekly) were assessed using the multidimensional, self-administered WOMAC (visual analog scale version) questionnaire.
                Sixty-six eligible patients completed the study. The mean initial and final daily doses of controlled release codeine were 50 mg every 12 h at baseline and 159 mg every 12 h at the final assessment. All variables in the efficacy analysis indicated superiority of controlled release codeine over placebo. The WOMAC pain scale showed an improvement of 44.8% over baseline in the controlled release codeine group compared with 12.3% taking placebo (p = 0.0004). For the WOMAC stiffness and physical function scales the improvements over baseline on controlled release codeine were 47.7% and 49.3%, respectively compared with 17.0% and 17.0%, respectively, with placebo (p = 0.003; p = 0.0007). Controlled release codeine was also significantly better than placebo on measures of sleep quality and requirement for supplemental acetaminophen.
                Single entity controlled release codeine is an effective treatment for pain due to OA of the hip or knee. To compare oxymorphone extended release (ER) and placebo on indices of pain, function, and safety in patients with chronic osteoarthritis (OA) pain.
                In this multicenter, double-blind, placebo- and active-controlled, parallel-group, dose-ranging study, patients were randomized to oxymorphone ER 20 mg (N = 121), oxymorphone ER 40 mg (N = 121), oxycodone controlled release 20 mg (N = 125), or placebo (N = 124) every 12 hours. The primary efficacy end point was change in arthritis pain intensity (visual analog scale, 0-100) from baseline to week 3 for the oxymorphone ER 40 mg group versus placebo.
                The primary end point was achieved: the week 3 oxymorphone ER least squares mean difference (LSMD) from placebo was -9.0 (95% confidence interval [CI]: -16.2 to -1.8; P = 0.015). Secondary efficacy analysis showed similar improvements at week 4 (LSMD from placebo, -10.3 [95% CI: -17.7 to -2.8]; P = 0.007) and with oxymorphone ER 20 mg at week 3 (LSMD from placebo, -7.7 [95% CI: -15.0 to -0.4]; P = 0.039) and week 4 (LSMD from placebo, -7.5 [95% CI: -15.0 to 0.0]; P = 0.050). Weeks 3 and 4 pain intensity decreased by approximately 30-40%. Oxymorphone ER 20 and 40 mg improved from baseline on the Western Ontario and McMaster Universities Osteoarthritis Composite Index and pain and physical function subscales at week 4. Adverse events in all opioid groups included mild to moderate nausea, constipation, and somnolence.
                In this short-term study, oxymorphone ER was superior to placebo for relieving pain and improving function in patients with moderate to severe chronic OA pain, and is an alternative to other sustained-release opioids. This study examines the impact of controlled-release oxycodone (OxyContin) on cognitive-behavioral indicators of efficacy beliefs and coping efforts in patients with osteoarthritis who experience persistent pain.
                This was a double-blind, placebo-controlled study of 104 male and female patients with osteoarthritis who experienced moderate to severe pain. Pain assessment, arthritis helplessness, and coping efforts were assessed before and after for treatment and placebo control groups.
                Examination of differences between treatment and control groups after 2 weeks revealed significant reductions in reported pain, improvements in coping efficacy, and reductions in helplessness and passive coping in response to controlled-release oxycodone treatment compared to placebo. Changes in pain partially mediated the effects on coping in subsequent assessments.
                The findings indicate that controlled-release oxyco- done treatment accounted for improvements in coping with pain beyond that of placebo controls. This medication may be most beneficial to osteoarthritis patients when incorporated as part of a multidisciplinary approach to pain management. Although common treatments for osteoarthritis (OA) pain, such as nonsteroidal antiinflammatory drugs (NSAIDs), simple analgesics, and weak opioids, provide relief in some cases, they fail to control pain or are poorly tolerated in many cases. Strong opioids have been used to successfully treat several types of noncancer pain but have rarely been tested in controlled studies. Therefore, we tested the effects of transdermal fentanyl (TDF) in patients with moderate-to-severe OA pain, in a placebo-controlled study.
                The cohort comprised patients with radiologically confirmed OA of the hip or knee (meeting the American College of Rheumatology criteria) requiring joint replacement and with moderate-to-severe pain that had been inadequately controlled by weak opioids. The patients were randomized to receive TDF or placebo for 6 weeks after a 1-week pretreatment run-in phase. During study treatment, previously prescribed NSAIDs and simple analgesics were continued, but weak opioids were discontinued. All patients had access to paracetamol and metoclopramide. Pain was recorded on a visual analog scale (VAS), and function was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC).
                Data were available for 399 patients (202 receiving TDF, 197 receiving placebo), of whom 199 (50%) completed the study. TDF provided significantly better pain relief than placebo, as demonstrated by the primary outcome measure (area under the curve for VAS scores -20 in the TDF group versus -14.6 in the placebo group; P = 0.007). TDF was also associated with significantly better overall WOMAC scores and pain scores. The most common adverse events were nausea, vomiting, and somnolence, and these occurred more often in the TDF group.
                TDF can reduce pain and improve function in patients with knee or hip OA. Oxytrex is a novel drug that combines oxycodone with ultralow-dose naltrexone, an opioid antagonist. Ultralow-dose opioid antagonists have been demonstrated to enhance and prolong opiate analgesia and alleviate opioid tolerance and withdrawal in rodents. This 3-week, Phase II clinical trial assessed safety and analgesic efficacy of Oxytrex in patients with moderate to severe pain from osteoarthritis. Patients with a pain score > or =5 received placebo, oxycodone 4 times a day (qid), Oxytrex qid, or Oxytrex twice a day (bid). All active treatment groups received the same total daily dose and dose escalation of oxycodone starting at 10 and ending at 40 mg/day. Importantly, the Oxytrex bid group received a lower daily dose of naltrexone than Oxytrex qid (0.002 vs 0.004 mg/day). Oxytrex bid produced a 39% reduction in pain intensity, which was significantly greater than that of placebo (P < .001), oxycodone qid (P = .006), and Oxytrex qid (P = .003). Oxytrex bid was also superior to placebo in quality of analgesia (P = .002), duration of pain control each day (P = .05), patients' global assessments (P = .04), and the Western Ontario and MacMaster Universities Osteoarthritis Index total score (P = .03). The incidence of side effects was comparable between active treatments. In this Phase II dose-ranging study, Oxytrex bid demonstrated greater pain relief with a more convenient dosing schedule compared to oxycodone qid.
                Preclinical data have shown ultralow-dose opioid antagonists to enhance and prolong opioid analgesia while reducing analgesic tolerance and physical dependence. Recent molecular pharmacology data show a mechanism of action to be the prevention of aberrant G protein coupling by opioid receptors that underlies opioid tolerance and dependence. The analgesic efficacy of 200 mg ibuprofen plus 30 mg codeine, 200 mg ibuprofen and placebo was investigated in a new analgesic evaluation model using single- and repeated-dose administration. The study was a double-blind randomized cross-over investigation in 26 coxarthrosis patients with persistent pain. After a washout period of at least 2 days with paracetamol available as rescue analgesic, each of the 3 treatments was administered in a total of 6 doses during 24 h. The hourly pain intensity was recorded on a 100-mm visual analogue scale (VAS) for 8 h after the 1st and the 6th dose. The pretreatment VAS score was 31-37 mm. After the 1st dose the 8-h mean pain intensity values were 25, 27, and 26 mm after ibuprofen plus codeine, ibuprofen, and placebo, respectively. Following another 5 doses every 4 h the corresponding values were 10, 17 and 29 mm. Repeated administration of both active drugs reduced the pain intensity significantly. The analgesic efficacy of ibuprofen plus codeine was significantly superior to that of ibuprofen which was, in turn, superior to that of placebo. In conclusion, analgesic efficacy was better differentiated after repeated-dose than after single-dose administration. The present study design was able to differentiate between 200 mg ibuprofen plus 30 mg codeine and 200 mg ibuprofen alone in a relatively small number of patients. A randomized, 4-week, double-blind trial followed by an open-label extension trial assessed the efficacy and safety of a once-daily, extended-release morphine formulation (Avinza (previously referred to as Morphelan)) in 295 patients with chronic, moderate-to-severe osteoarthritis pain who had failed to obtain adequate pain relief with NSAIDs and acetaminophen. Participants received one of four treatments: Avinza 30 mg once daily (QAM or QPM), MS Contin(R) 15 mg twice daily, or placebo twice daily. Patients (n =181) received Avinza QAM or QPM during the 26-week open-label extension trial and could increase their dose to optimize pain control. Avinza and MS Contin reduced pain and improved several sleep measures versus placebo. Analgesic efficacy was comparable between Avinza and MS Contin; however, Avinza QAM demonstrated greater improvements in overall quality of sleep. The most common adverse events were constipation and nausea. The majority of AEs occurred at a similar incidence among the active treatment groups. This randomized, double-blind, multi-centre study was undertaken to evaluate the efficacy and safety of treatment for 4 weeks with codeine plus paracetamol versus paracetamol in relieving chronic pain due to osteoarthritis of the hip. A total of 158 outclinic patients entered the study. Eighty-three patients (mean age 66 years) were treated with codeine 60 mg plus paracetamol 1 g 3 times daily, and 75 patients (mean age 67 years) with paracetamol 1 g 3 times daily. Ibuprofen 400 mg was prescribed as rescue medication. Due to an unexpected high rate of adverse drug reactions, the study was closed before the planned 400 patients had entered. Over weeks 1-4, 87%, 64%, 61% and 52% of patients in the codeine plus paracetamol group, and 38%, 31%, 22% and 29% of patients in the paracetamol group had one or more adverse drug reactions. Significantly more patients in the codeine plus paracetamol group had adverse drug reactions in each of the 4 weeks. Nausea, dizziness, vomiting and constipation were predominant adverse reactions in the codeine plus paracetamol group. During the first week of treatment, 30 patients (36%) in the codeine plus paracetamol group and 9 (12%) in the paracetamol group dropped out. As evaluated from patients completing the first week of treatment, the pain intensity during that week compared to their baseline pain was significantly lower in the codeine plus paracetamol group than in the paracetamol group. Moreover, during the first week the paracetamol group received rescue medicine significantly more frequently. In conclusion, when evaluated after 7 days of treatment, the daily addition of codeine 180 mg to paracetamol 3 g significantly reduced the intensity of chronic pain due to osteoarthritis of the hip joint. However, several adverse drug reactions, mainly of the gastrointestinal tract, and the larger number of patients withdrawing from treatment means that the addition of such doses of codeine cannot be recommended for longer-term treatment of chronic pain in elderly patients.
The small to moderate beneficial effects of non-tramadol opioids are outweighed by large increases in the risk of adverse events. Non-tramadol opioids should therefore not be routinely used, even if osteoarthritic pain is severe.