oxymorphone and Osteoarthritis--Knee

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.

Topics: Analgesics, Opioid; Delayed-Action Preparations; Dose-Response Relationship, Drug; Double-Blind Method; Drug Administration Schedule; Female; Humans; Male; Middle Aged; Osteoarthritis, Hip; Osteoarthritis, Knee; Oxymorphone; Pain Measurement; Sleep; Treatment Outcome

To examine the development of analgesic tolerance in patients on oxymorphone extended-release (OxymER).. Post hoc analysis of data from a previously conducted prospective 1 year multi-center open-label extension study in which patients were able to titrate as needed.. Sample of 153 hip and knee osteoarthritis (OA) subjects on OxymER. Primary analyses were limited to study completers (n = 62) due to the large amount of missing data for the noncompleters (n = 91).. Main outcome measures included OxymER doses (pill counts) and pain intensity ratings using a visual analog scale at monthly visits.. There were significant dose increases from weeks 1 to 2 and 2 to 6 (P < 0.05). Doses stabilized around week 6, suggesting the completion of what we defined as "titration." Both doses and pain ratings were stable when this titration phase was excluded from the analysis (P = 0.751; P = 0.056, respectively). Only 28% of the patients had any dose changes following this titration. While there was a significantly greater dose at week 52 compared with week 10 (P = 0.010), the increase in dose became insignificant after excluding four subjects who required two dose increases (P = 0.103).. The results showed that most of the titration/dose stabilization changes occurred within the first 10 weeks. A minority (28%) of subjects required dosage increases after this (defined) titration period. Pain reports stabilized statistically after 2 weeks. The findings of this post hoc analysis suggest a lack of opioid tolerance in the majority (72%) of these OA patients who completed this study following a defined titration period on OxymER.. This post hoc analysis of oxymorphone ER consumption in osteoarthritis pain vs pain report showed that most dose changes occurred during an initial "titration period" as defined. Following this titration few subjects increased dose and analgesia remained stable. These findings suggest a lack of longitudinal opioid tolerance in the majority of those OA subjects who completed the trial.

Topics: Adult; Aged; Aged, 80 and over; Analgesics, Opioid; Chemistry, Pharmaceutical; Dose-Response Relationship, Drug; Drug Tolerance; Female; Humans; Longitudinal Studies; Male; Middle Aged; Multicenter Studies as Topic; Osteoarthritis, Hip; Osteoarthritis, Knee; Oxymorphone; Pain; Pain Measurement; Prospective Studies; Treatment Outcome