Paracetamol and the placebo effect in osteoarthritis trials: a missing link?

Rescue Analgesic Medication Use by Patients Treated with Triamcinolone Acetonide Extended-Release for Knee Osteoarthritis Pain: Pooled Analysis of Three Phase 2/3 Randomized Clinical Trials

INTRODUCTION

In clinical trials for knee osteoarthritis (OAK), rescue medication is commonly provided to manage uncontrolled index-knee pain. The impact of treatment on rescue medication utilization provides important information on the robustness of analgesic effect. In randomized controlled OAK trials (NCT01487161, NCT02116972, NCT02357459), intra-articular (IA) triamcinolone acetonide extended-release (TA-ER) demonstrated substantial, prolonged analgesia versus saline-placebo and TA crystalline solution (TAcs) as assessed by patient-reported pain scales. This pooled analysis assessed the impact of TA-ER on rescue medication use.

METHODS

Patients (N = 798) with OAK (American College of Rheumatology criteria; Kellgren-Lawrence grade 2/3) and baseline average daily pain intensity score ≥ 5 to ≤ 9 (0-10 numeric rating scale) received a single IA injection of TA-ER (N = 324), saline-placebo (N = 262), or TAcs (N = 212). Acetaminophen/paracetamol tablets were provided to treat uncontrolled pain (knee or otherwise). Rescue medication consumption was monitored through a daily diary; pill counts were confirmed at the clinical site. Differences in rescue medication use were measured by least-squares mean (LSM) differences, number of rescue medication tablets used per day, and in area under the effect (AUE) curves of rescue medication tablets used per week.

RESULTS

The overall number of rescue medication tablets used per day through week 24 was significantly less (p ≤ 0.05) for TA-ER versus saline-placebo (LSM difference, - 0.43) and TAcs (- 0.24). Rescue medication use was significantly (p ≤ 0.05) lower following TA-ER versus saline-placebo across weeks 1-12 (AUE_weeks1-12; LSM difference, - 24.5) and weeks 1-24 (AUE_weeks1-24; - 51.6) and versus TAcs across weeks 1-12 (AUE_weeks1-12; - 21.1).

CONCLUSIONS

In patients with painful OAK, reduced rescue medication use may be a potential benefit of TA-ER and further supports its analgesic efficacy. Additional research is needed to assess whether TA-ER impacts the use of other common oral analgesics (nonsteroidal anti-inflammatory drugs, opioids) for patients with OAK.

FUNDING

Flexion Therapeutics, Inc., Burlington, MA, USA. Plain language summary available for this article.

Analgesic Effect of the Newly Developed S(+)-Flurbiprofen Plaster on Inflammatory Pain in a Rat Adjuvant-Induced Arthritis Model

Preclinical Research This article describes the properties of a novel topical NSAID (Nonsteroidal anti-inflammatory drug) patch, SFPP (S(+)-flurbiprofen plaster), containing the potent cyclooxygenase (COX) inhibitor, S(+)-flurbiprofen (SFP). The present studies were conducted to confirm human COX inhibition and absorption of SFP and to evaluate the analgesic efficacy of SFPP in a rat adjuvant-induced arthritis (AIA) model. COX inhibition by SFP, ketoprofen and loxoprofen was evaluated using human recombinant COX proteins. Absorption of SFPP, ketoprofen and loxoprofen from patches through rat skin was assessed 24 h after application. The AIA model was induced by injecting Mycobacterium tuberculosis followed 20 days later by the evaluation of the prostaglandin PGE2 content of the inflamed paw and the pain threshold. SFP exhibited more potent inhibitory activity against COX-1 (IC50  = 8.97 nM) and COX-2 (IC50  = 2.94 nM) than the other NSAIDs evaluated. Absorption of SFP was 92.9%, greater than that of ketoprofen and loxoprofen from their respective patches. Application of SFPP decreased PGE2 content from 15 min to 6 h and reduced paw hyperalgesia compared with the control, ketoprofen and loxoprofen patches. SFPP showed analgesic efficacy, and was superior to the ketoprofen and loxoprofen patches, which could be through the potent COX inhibitory activity of SFP and greater skin absorption. The results suggested SFPP can be expected to exert analgesic effect clinically.

Osteoarthritis treatment using autologous conditioned serum after placebo

BACKGROUND AND PURPOSE

Autologous conditioned serum (ACS) is a disease-modifying drug for treatment of knee osteoarthritis, and modest superiority over placebo was reported in an earlier randomized controlled trial (RCT). We hypothesized that when given the opportunity, placebo-treated patients from that RCT would now opt for ACS treatment, which would result in a greater clinical improvement than placebo.

METHODS

Of 74 patients treated with placebo in the previous trial, 20 opted for ACS treatment. Patients who did not choose further treatment were interviewed about their reasons. Clinical improvement of the 20 ACS-treated patients was measured using knee-specific clinical scores, as was "response shift" at 3 and 12 months.

RESULTS

In the 20 patients who did opt for ACS, the visual analog scale (VAS) score for pain improved; but after 12 months, clinical results were similar to those after placebo treatment. Response shift measurement demonstrated that the 20 patients had adapted to their disabilities during treatment.

INTERPRETATION

Placebo-treated patients from an earlier trial were reluctant to undergo ACS treatment, in part due to the laborious nature of the therapy. In a subset of patients who opted for treatment, ACS treatment after placebo did not result in greater clinical improvement than placebo treatment only. However, due to the limited power of the current study and possible selection bias, definite advice on using or refraining from ACS cannot be given.

Topical Ginger Treatment With a Compress or Patch for Osteoarthritis Symptoms

AIM

This article is a report of a study evaluating changes in health status before and after topical ginger treatment for adults with moderate to severe osteoarthritis.

METHOD

In 2011, 20 adults with chronic osteoarthritis were randomly assigned to one of two groups for 7 consecutive days of topical ginger treatment by trained nurses: Group 1 received a manually prepared ginger compress and Group 2 a standardized ginger patch. Participants had the option to continue self-treatment using the ginger patch for a further 24 weeks. A brief arthritis health questionnaire was completed weekly for 3 weeks and 4 weekly for 24 weeks.

RESULTS

The mean scores for Group 1 and Group 2 show a notable decline following 1-week topical ginger treatment; scores in pain, fatigue, global effect, and functional status reduced by 48%, 49%, 40%, and 31%, respectively, whereas health satisfaction improved from 80% dissatisfied to 70% satisfied. Scores for all participants in all five domains progressively reduced over the following 24 weeks of self-treatment.

CONCLUSION

Topical ginger treatment has the potential to relieve symptoms, improve the overall health, and increase independence of people with chronic osteoarthritis.

Ginger Therapy for Osteoarthritis: A Typical Case

PURPOSE

To describe a treatment for osteoarthritis known as ginger therapy applied by anthroposophic nurses for a specific personality type.

BACKGROUND

Ginger has been used medicinally in Asia since ancient times to bring inner warmth. Ginger therapy is part of the tradition of anthroposophic nursing, when managing chronic inflammatory conditions such as osteoarthritis. Osteoarthritis is a progressive disease of the synovial joint tissue that primarily affects those older than 65 years, causing pain on movement.

DESIGN

A patient with specific characteristics suffering osteoarthritis received 7 consecutive days of ginger therapy by anthroposophic nurses at an integrative medical center. Two weeks after the therapy, education was given to enable self-treatment in the home for a further 24 weeks. Data were obtained using body physiological recordings, a case diary and pain scale, and self-report arthritis Health Assessment Questionnaire.

FINDINGS

Ginger therapy activated a marked relief of osteoarthritis symptoms that progressively improved over the 24 weeks, with no negative effects reported. Ginger therapy needs to be considered by nurses caring for specific personality types with osteoarthritis.

A prospective, randomized, double-blind, multicenter comparative study on the safety and efficacy of Celecoxib and GCSB-5, dried extracts of six herbs, for the treatment of osteoarthritis of knee joint

ETHNOPHARMACOLOGICAL RELEVANCE

This prospective, randomized, double-blind, multicenter study compared the efficacy and safety of Celecoxib and GCSB-5, a new product from extracts of six herbs, for the treatment of knee osteoarthritis.

MATERIALS AND METHODS

A total of 198 eligible patients were randomly assigned to the Celecoxib group (n=99 patients) or the GCSB-5 group (n=99 patients) for the 12-week study. The amount of change and percentage of the change in Western Ontario and McMaster Universities (WOMAC) Arthritis Index from the baseline, the change in pain on walking by visual analogue scale (VAS), physician's global assessment on response to therapy (PGART) by five point Likert scale, and the amount of rescue medicine taken were used as parameters for efficacy. Adverse drug reactions (ADRs) were carefully investigated.

RESULTS

The WOMAC score improved in both the Celecoxib group and GCSB-5 group by 20.5 and 21.3 (P=0.79). The percentage of the change in WOMAC score were -42.0% and -38.9% (P=0.54). The pain VAS score decreased by 29.9 and 27.9 (P=0.58). The responders by PGART were 95.3% and 93.8% (P= 0.66), and the median amount of rescue medicine taken were 2.0 and 6.5 tablets (P=0.06). The incidence of ADRs were 31.3% and 21.2% (P=0.11). The most common ADRs were gastrointestinal system related; 17.2% in GCSB-5 group and 22.2% in Celecoxib group. Any severe ADR was not observed in either group.

CONCLUSIONS

The result of this study supports that GCSB-5 is comparable to Celecoxib in terms of the efficacy and safety for the treatment of osteoarthritis of knee joint.