Placebo Response: Relevance to the Rheumatic Diseases

The placebo effect: why we should care

Contrary to its definition, a placebo is far from an inert substance but carries meaningful responses that can mediate significant outcome results in pharmacotherapeutic studies. The advent of detailed studies and modern imaging techniques have provided the basis to understand the underlying mechanisms of the placebo effect, as well as its localization to determined brain centers. Designing clinical trials using principles of classical conditioning to mediate placebo effects may enhance treatment outcomes and provide novel pharmacotherapeutic modalities.

Management of chronic pain in the rheumatic diseases with insights for the clinician

Pain that accompanies musculoskeletal conditions should be regarded as an illness entity in its own right and deserves treatment in parallel with the management of the underlying condition. Recent understanding of the pathophysiology of rheumatic pain invokes interplay of the nociceptive mechanisms driven by local tissue factors and the neurogenic responses that sustain chronic pain. In line with other pain conditions, ideal treatment of rheumatic pain should be through a multimodal approach, integrating nonpharmacologic as well as pharmacologic treatments. In the light of this new concept of pain mechanisms, future pharmacologic treatment options may encompass a wider scope than the use of traditional analgesics and nonsteroidal anti-inflammatory drugs. There is currently limited experience for use of pharmacologic treatments that act primarily on neurogenic mechanisms in rheumatic conditions. Drug combination studies are lacking, but this strategy seems clinically reasonable to allow for an approach to treating pain from different mechanistic perspectives. An added advantage would be the opportunity to use lower doses of individual drugs and thereby reduce the side effect profile. Ideal pain management must also include attention to the important co-associates of pain such as effects on sleep, mood and energy, which all have an impact on the global burden of suffering. Although complete relief of pain is still an unrealistic objective, reasonable outcome goals for symptom relief should be accompanied with an improvement in function.

The placebo effect in rheumatology: new data

The placebo effect is often poorly understood or confused with evaluation bias or spontaneous improvement, particularly when study inclusion criteria select patients at the peak of their symptoms. Cerebral imaging studies have confirmed that the placebo effect exists, although it is now known to involve a combination of conditioned reflexes and reward anticipation. The magnitude of the placebo effect can be evaluated by randomly dividing patients into three groups, one of which receives no treatment at all; by crossover studies; or by the newly developed open-hidden study design. This last design has established that rebound effects can occur after placebo discontinuation, and other experiments have shown that anxiety is associated with a weaker placebo response. This anti-placebo effect of anxiety, similar to the nocebo effect, may involve the release of cholecystokinin. The strength of the placebo effect varies across procedures and joints. A marked placebo effect can be seen in rheumatology patients, as shown recently by two high-quality double-blind studies that found no difference between vertebroplasty and a sham procedure. Effective blinding is crucial both to obtain a strong placebo effect and to separate an intrinsic effect from a placebo effect. Beliefs of the patients and physicians regarding the active drug and the existence and strength of the placebo effect could also be usefully evaluated throughout clinical studies.

Functional neural correlates of mindfulness meditations in comparison with psychotherapy, pharmacotherapy and placebo effect. Is there a link?

Chiesa A, Brambilla P, Serretti A. Functional neural correlates of mindfulness meditations in comparison with psychotherapy, pharmacotherapy and placebo effect. Is there a link?

OBJECTIVE

Mindfulness meditations (MM) are a group of meditation practices which are increasingly receiving attention. The aim of the present work is to review current findings about the neural correlates of MM and compare such findings with other specific and non-specific treatments.

METHODS

A literature search was undertaken using MEDLINE, ISI web of knowledge, the Cochrane database and references of retrieved articles. Studies which focused on the functional neural correlates of MM, psychotherapy, pharmacotherapy and placebo published up to August 2009 were screened in order to be considered for the inclusion.

RESULTS

Main findings suggest that long-term MM practice allows a more flexible emotional regulation by engaging frontal cortical structures to dampen automatic amygdala activation. A large overlap exists between cerebral areas activated during MM, psychotherapy, pharmacotherapy and those activated by placebo. However, while MM, psychotherapy and placebo seem to act through a top-down regulation, antidepressants seem to act through a bottom-up process.

CONCLUSION

MM seem to target specific brain areas related to emotions and emotional regulation. Similar mechanisms have been observed also in other interventions, particularly psychotherapy.

A double-blind, randomized, saline-controlled study of the efficacy and safety of EUFLEXXA for treatment of painful osteoarthritis of the knee, with an open-label safety extension (the FLEXX trial)

OBJECTIVE

To report the FLEXX trial, the first well-controlled study assessing the safety and efficacy of Euflexxa (1% sodium hyaluronate; IA-BioHA) therapy for knee osteoarthritis (OA) at 26 weeks.

METHODS

This was a randomized, double-blind, multicenter, saline-controlled study. Subjects with chronic knee OA were randomized to 3 weekly intra-articular (IA) injections of either buffered saline (IA-SA) or IA-BioHA (20 mg/2 ml). The primary efficacy outcome was subject recorded difference in least-squares means between IA-BioHA and IA-SA in subjects' change from baseline to week 26 following a 50-foot walk test, measured via 100-mm visual analog scale (VAS). Secondary outcome measures included Osteoarthritis Research Society International responder index, Western Ontario McMaster University Osteoarthritis Index VA 3.1 subscales, patient global assessment, rescue medication, and health-related quality of life (HRQoL) by the SF-36. Safety was assessed by monitoring and reporting vital signs, physical examination of the target knee following injection, adverse events, and concomitant medications.

RESULTS

Five hundred eighty-eight subjects were randomized to either IA-BioHA (n = 293) or IA-SA (n = 295), with an 88% 26 week completion rate. No statistical differences were noted between the treatment groups at baseline. In the IA-BioHA group, mean VAS scores decreased by 25.7 mm, compared with 18.5 mm in the IA-SA group. This corresponded to a median reduction of 53% from baseline for IA-BioHA and a 38% reduction for IA-SA. The difference in least-squares means was -6.6 mm (P = 0.002). Secondary outcome measures were consistent with significant improvement in Osteoarthritis Research Society International responder index, HRQoL, and function. Both IA-SA and IA-BioHA injections were well tolerated, with a low incidence of adverse events that were equally distributed between groups. Injection-site reactions were reported by 1 (<1%) subject in the IA-SA group and 2 (1%) in the IA-BioHA group.

CONCLUSIONS

IA-BioHA therapy resulted in significant OA knee pain relief at 26 weeks compared with IA-SA. Subjects treated with IA-BioHA also experienced significant improvements in joint function, treatment satisfaction, and HRQoL.