Around-the-clock, controlled-release oxycodone therapy for osteoarthritis-related pain: placebo-controlled trial and long-term evaluation.

BACKGROUND: Although opioid analgesics have well-defined efficacy and safety in treatment of chronic cancer pain, further research is needed to define their role in treatment of chronic noncancer pain. OBJECTIVE: To evaluate the effects of controlled-release oxycodone (OxyContin tablets) treatment on pain and function and its safety vs placebo and in long-term use in patients with moderate to severe osteoarthritis pain. METHODS: One hundred thirty-three patients experiencing persistent osteoarthritis-related pain for at least 1 month were randomized to double-blind treatment with placebo (n = 45) or 10 mg (n = 44) or 20 mg (n = 44) of controlled-release oxycodone every 12 hours for 14 days. One hundred six patients enrolled in an open-label, 6-month extension trial; treatment for an additional 12 months was optional. RESULTS: Use of controlled-release oxycodone, 20 mg, was superior (P<.05) to placebo in reducing pain intensity and the interference of pain with mood, sleep, and enjoyment of life. During long-term treatment, the mean dose remained stable at approximately 40 mg/d after titration, and pain intensity was stable. Fifty-eight patients completed 6 months of treatment, 41 completed 12 months, and 15 completed 18 months. Common opioid side effects were reported, several of which decreased in duration as therapy continued. CONCLUSIONS: Around-the-clock controlled-release oxycodone therapy seemed to be effective and safe for patients with chronic, moderate to severe, osteo-arthritis-related pain. Effective analgesia was accompanied by a reduction in the interference of pain with mood, sleep, and enjoyment of life. Analgesia was maintained during long-term treatment, and the daily dose remained stable after titration. Typical opioid side effects were reported during short- and long-term therapy.

Effect of pregnancy on immune complexes and rheumatoid factors in patients with rheumatoid arthritis.

Rheumatoid arthritis is associated with circulating and intra-articular immune complexes and rheumatoid factors. The clinical activity of rheumatoid arthritis improves during pregnancy in the majority of women, with exacerbation following delivery. Concentrations of immune complexes, as detected by the Clq-binding assay, the Clq-solid phase assay, and the monoclonal rheumatoid factor-solid phase assay, decreased during gestation, with elevations following delivery. Concentrations of IgM-rheumatoid factor and IgG-rheumatoid factor, analyzed by radioimmunoassay, changed variably during pregnancy, increasing in some patients and decreasing in others. When examined serially before, during, and following pregnancy, changes in the concentration of circulating immune complexes and/or rheumatoid factors corresponded with the clinical changes in three patients. These observations document the significant effect of gestation on the concentration of circulating immune complexes in patients with rheumatoid arthritis. They also support the role of these laboratory tests in monitoring the clinical course of rheumatoid arthritis.

Detection of antibodies to streptococcal mucopeptide in patients with rheumatic disorders and normal controls.

Bacterial mucopeptide is an integral part of bacterial cell walls and is therefore ubiquitous in our environment. An enhanced degree of humoral immunity has ben detected not only in patients with acute rheumatic fever (ARF), with a known recent response to streptococci, but also in patients with adult and juvenile rheumatoid arthritis (RA and JRA). Our studies confirmed this association with ARF and JRA using a precipitin system as well as a radioimmunoassay to detect IgG anti-mucopeptide antibodies. In those with adult RA, either IgM or IgA rheumatoid factors or IgM or IgA antibodies specific for mucopeptide were responsible for the increased incidence of precipitins to mucopeptide in the RA patients detected in this and other studies. No differences in the specificities of the anti-mucopeptide antibodies were noted between the various patient populations as there were no lines of partial identity or nonidentity when examined by Ouchterlony double diffusion analyses. Additionally, no differences of anti-mucopeptide antibody were observed when the sera from these same patient populations were examined employing inhibition studies utilizing N-acetylglucosamine and rhamnose.

Rheumatoid factor interference with the latex agglutination test for fibrin degradation products.

The latex agglutination test for FDP is widely employed clinically to aid in the diagnosis of DIC and other conditions. Of sera containing RF, 93% demonstrated positive FDP latex agglutination tests. Reducing agents in all instances destroyed the RF agglutinating capability. Futhermore, 86% of sera positive for FDP and RF became FDP-negative following reduction. Therefore RF was responsible for false-positive FDP latex agglutination tests in the majority of patients. Reduction of patient sera is a rapid, simple method to distinguish a positive FDP test from a false-positive due to RF.