Conducting clinical trials to establish drug efficacy in chronic pain

Perineural steroid injections around ilioinguinal, iliohypogastric, and genitofemoral nerves for treatment of chronic refractory neuropathic pain: A retrospective study

Background: Perineural local anaesthetic and steroid injections around ilioinguinal (II), iliohypogastric (IH), and genitofemoral (GF) nerves are often performed to treat chronic refractory neuropathic pain in the lower abdomen and groin, but there is a lack of published data on outcomes of these interventions. Aims: The objective of this retrospective study was to evaluate analgesic outcomes of ultrasound-guided II, IH, and GF nerve blocks in patients with chronic neuropathic pain in the lower abdominal wall and groin. Methods: Analgesic outcomes were assessed at 6 weeks after injections and patients were classified as "responders" if the numerical rating scale for pain score reduced by 30% or more. Variables analyzed for impact on outcomes included demographics, intensity of pain and duration, etiology, dose of opioid, presence of anxiety, depression, and diabetes mellitus. Results: In this cohort of 54 patients with severe baseline pain who had failed to receive analgesic benefit from recommended first- and second-line medications for neuropathic pain, 30 patients had history of surgery and 24 had pain secondary to visceral inflammatory pathologies. Twenty-five (46.3%) patients were identified as responders. A majority of the patients in this cohort had pain for more than one year. There was a higher incidence of diabetes mellitus in nonresponders compared to responders but the difference was not significant (14% and 0%, respectively; P = 0.115). Conclusions: Ultrasound-guided perineural steroids can ameliorate chronic refractory abdominal wall and groin neuropathic pain in patients who have failed to respond to conventional medical management at 6 weeks after the procedures.

Effect of Milnacipran on Pain in Patients with Rheumatoid Arthritis with Widespread Pain: A Randomized Blinded Crossover Trial

OBJECTIVE

Clinical trials have shown that serotonin norepinephrine reuptake inhibitors, such as milnacipran, decrease pain in noninflammatory pain conditions such as fibromyalgia and osteoarthritis. We examined the effect of milnacipran on self-reported pain intensity and experimental pain sensitivity among patients with rheumatoid arthritis (RA) with widespread pain and stable RA disease activity.

METHODS

In this double-blind, crossover study, patients with RA with widespread pain, receiving a stable treatment regimen, were randomized (by a random number generator) to receive milnacipran 50 mg twice daily or placebo for 6 weeks, followed by a 3-week washout and crossed over to the other arm for the remaining 6 weeks. The primary outcome was change in average pain intensity, assessed by the Brief Pain Inventory short form. The sample size was calculated to detect a 30% improvement in pain with power = 0.80 and α = 0.05.

RESULTS

Of the 43 randomized subjects, 41 received the study drug, and 32 completed the 15-week study per protocol. On a 0-10 scale, average pain intensity decreased by 0.39 (95% CI -1.27 to 0.49, p = 0.37) more points during 6 weeks of milnacipran treatment compared with placebo. In the subgroup of subjects with swollen joint count ≤ 1, average pain intensity decreased by 1.14 more points during 6 weeks of milnacipran compared with placebo (95% CI -2.26 to -0.01, p = 0.04). Common adverse events included nausea (26.8%) and loss of appetite (9.7%).

CONCLUSION

Compared with placebo, milnacipran did not improve overall, self-reported pain intensity among subjects with widespread pain receiving stable RA medications.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01207453.

Alexander technique and Feldenkrais method: a critical overview

This article develops an overall better understanding of the Alexander technique and Feldenkrais method. Initially, a brief history is provided to lay the groundwork for the development of these techniques. A description of the techniques, training requirements, and mechanism of action follows. Indications, contraindications, and patient selection are discussed. This article reviews and identifies what research has been completed and what areas need further investigation. Overall, the goal is to establish a guide to aid in determining who may benefit from these techniques and outcomes to expect when using these techniques.

Appropriate methods to assess the effectiveness and efficacy of treatments or interventions to control cancer pain

Pain is common in cancer patients. To ensure optimal pain management efficacy and effectiveness of new drugs and treatments have to be investigated in clinical trials. Efficacy trials such as randomised controlled trials (RCT) are experimental studies and estimate the maximum potential benefit to be derived from an intervention in ideal circumstances and under a controlled environment. RCTs are the only trial design to establish causal effects. A crossover study is a special type of RCT where patients serve as own controls. In efficacy studies the intervention and the control group should be as homogeneous as possible, confounding variables are controlled, bias is reduced, internal validity is high whereas external validity is low. Studies looking at effectiveness assess clinical practice and reflect real life circumstances. They rely high on external validity at the expense of careful controls, the study population is heterogeneous, confounding variables are examined. Cohort studies follow a group or groups of individuals with a common characteristic over a period of time to measure outcomes. Case-control studies start with the outcome and compare the characteristics of two groups of interest, those with the outcome and those without to identify factors which occur more or less often in the poor outcome group. Definition of outcome criteria is crucial both for efficacy and effectiveness studies and is often a primary problem. All clinical studies must use valid and reliable outcome measures.