Articles: pain-clinics.
-
Randomized Controlled Trial Multicenter Study
Efficacy of naproxen in patients with sciatica: multicentre, randomized, double-blind, placebo-controlled trial.
This trial assessed the efficacy of naproxen in patients with sciatica in outpatient clinics across 4 Norwegian hospitals. A total of 123 adults with radiating pain below the knee (≥4 on a 0-10 numeric rating scale) and signs consistent with nerve root involvement were included. Participants were randomized to receive either naproxen 500 mg or a placebo twice daily for 10 days. ⋯ No differences were found for sciatica bothersomeness or consumption of rescue medication or opioids. Participants in the naproxen group exhibited an adjusted odds ratio of 4.7 (95% CI 1.3-16.2) for improvement by 1 level on the global perceived change scale. In conclusion, naproxen treatment showed small, likely clinically unimportant benefits compared with placebo in patients with moderate-to-severe sciatica.
-
Randomized Controlled Trial
A randomised controlled trial of the effect of intra-articular lidocaine on pain scores in inflammatory arthritis.
Chronic pain in inflammatory arthritis (IA) reflects a complex interplay between active disease in a peripheral joint and central pronociceptive mechanisms. Because intra-articular lidocaine may be used to abolish joint-specific peripheral input to the central nervous system, we aimed to validate its use as a clinical tool to identify those patients with IA whose pain likely incorporates centrally mediated mechanisms. We began by investigating whether there was a placebo response of intra-articular injection in patients with IA 1:1 randomised to receive intra-articular lidocaine or control (0.9% saline). ⋯ Firstly, the placebo effect of intra-articular injection was low: compared to baseline, the mean pain NRS score 5-minutes postinjection was reduced by 3.5 points in the lidocaine group vs 1.2 points in the control group. Secondly, postlidocaine NRS scores were significantly higher in those with a high (>18) baseline painDETECT score, fibromyalgia, and low-pressure pain threshold at the trapezius ( P = 0.002, P = 0.001, P = 0.005, respectively). Persistent high pain after intra-articular lidocaine injection could be used as an indicator of pronociceptive mechanisms that are centrally mediated, informing centrally targeted analgesic strategies.
-
Establishing clinically meaningful changes in pain experiences remains important for clinical trials of chronic pain treatments. Regulatory guidance and pain measurement initiatives have recommended including patient-reported global assessment measures (eg, Patient-Global Impression of Change [PGIC]) to aid interpretation of within-patient differences in domain-specific clinical trial outcomes (eg, pain intensity). The objectives of this systematic review were to determine the frequency of global assessment measures inclusion, types of measures, domains assessed, number and types of response options, and how measures were analyzed. ⋯ Response options and reference periods even differed within the PGIC. Global assessment measures were most commonly analyzed as continuous variables (n = 24; 46.2%) or as dichotomous variables with positive categories combined to calculate the proportion of participants with a positive response to treatment (n = 18; 34.6%). This review highlights the substantial work necessary to clarify measurement and use of patient global assessment in chronic pain trials and provides short- and long-term considerations for measure selection, reporting and analysis, and measure development.
-
Randomized Controlled Trial
Enhancing placebo analgesia: Unravelling the powerful interplay of ownership and verbal suggestion.
Placebo analgesic research demonstrates pain reduction after using a placebo analgesic. Recent studies have documented that sometimes possessing a placebo analgesic induces placebo analgesia. These prior studies used a 'cream' as the stimulus and proposed that the effect is driven by an expectancy of obtaining benefits from the owned analgesic. This paper examines three pivotal components of placebo analgesia: placebo form, ownership and expectancy induced by verbal suggestion. We investigate analgesic expectancy between cream versus oil form of placebo stimulus and systematically isolate the effects of ownership, verbal suggestion and their interaction, comparing with the effect of use, to decipher the dynamics of placebo analgesia. ⋯ This study delves into the intricate dynamics of placebo analgesia, shedding light on the significant influence of ownership and verbal suggestion. Through a meticulous exploration of the relationship between ownership and expectancy induced by verbal suggestion, we propose novel avenues for enhancing placebo responses. This research has implications for clinical practice and pain management strategies, potentially revolutionizing approaches to pain relief and therapeutic outcomes. Our findings contribute to a paradigm shift in understanding placebo analgesia, emphasizing the pivotal interaction between ownership and verbal suggestion.
-
Cannabidiol (CBD), the main nonpsychoactive cannabinoid of cannabis, holds promise for nonaddictive treatment of pain. Although preclinical studies have been encouraging, well-controlled human trials have been largely unsuccessful. To investigate this dichotomy and better understand the actions of CBD, we used high-content calcium imaging with automated liquid handling and observed broad inhibition of neuronal activation by a host of ionotropic and metabotropic receptors, including transient receptor potential (Trp) and purinergic receptors, as well as mediators of intracellular calcium cycling. ⋯ Taken together, these results demonstrate that CBD can reduce neuronal activity evoked by a strikingly wide range of stimuli implicated in pain signaling. The extensive effects underscore the need for further studies at substantially lower drug concentrations, which are more likely to reflect physiologically relevant mechanisms. The slow kinetics and block raise biophysical questions regarding the lipophilic properties of CBD and its action on channels and receptors within membranes.