Efficacy of a fixed combination of palmitoylethanolamide and acetyl-l-carnitine (PEA+ALC FC) in the treatment of neuropathies secondary to rheumatic diseases

Causal relationship between rheumatoid arthritis and carpal tunnel syndrome: a bidirectional two-sample Mendelian randomization study

BACKGROUND

Although there is considerable evidence of a robust correlation between rheumatoid arthritis (RA) and carpal tunnel syndrome (CTS) in previous research, the causal link between the two remains a topic of controversy.

METHODS

We conducted a two-sample Mendelian randomization (MR) study to explore the causal impact of RA on CTS. We obtained aggregate data from genome-wide association studies (GWAS) of CTS (ebi database and GEO database) and RA (FinnGen database). This study employed five MR analysis methods, with a focus on the inverse variance-weighted (IVW) method. Sensitivity analyses were conducted to ensure the robustness of the results of this study. Additionally, we performed reverse MR analysis.

RESULTS

We selected 84 and 78 single nucleotide polymorphisms (SNPs) significantly associated with RA from two databases as instrumental variables (IVs), respectively. Our results showed that RA patients have a higher risk of getting CTS regardless of whether the ebi database (IVW, OR = 1.045, 95% CI: 1.016-1.075, P = 0.002) or the GEO database (IVW, OR = 1.001, 95% CI: 1.001-1.002, P = 0.001) is selected for CTS data. However, the MR analysis showed no causal link between CTS and the increased risk of RA (ebi: IVW, OR = 1.084, 95% CI: 0.918-1.279, P = 0.341; GEO: IVW, OR = 1.968, 95% CI: 0.011-360.791, P = 0.799).

CONCLUSION

The analysis revealed that RA can increase the risk of CTS, but did not support the causal relationship that CTS can increase the risk of RA.

Trajectory of Change in the Severity of Symptoms in Patients with Fibromyalgia over 24 Months: Exploratory Analyses of a Combination Pharmacological Intervention

Symptoms of fibromyalgia (FM) fluctuate and vary in severity. The current study aimed to evaluate the efficacy of palmitoylethanolamide (PEA) and acetyl-L-carnitine (ALC) in FM patients over a 24-month period and to investigate the mediating function of pain catastrophizing subdomains in unfavorable relationships with disease severity levels in patients with FM. Patients were evaluated at baseline, after 12 months, and after 24 months, using different patient-reported measures (FIQR, FASmod, PSD, and PCS) to distinguish different levels of FM disease severity. A reduction of 30% or more from baseline was considered clinically important ("markedly improved"). A multivariate analysis was performed to identify the variables predictive of an FIQR reduction. Twenty-two patients (28.6%) were classified as "markedly improved", 16 patients (20.8%) as "slightly/moderately improved", and 39 patients (50.6%) as "not improved." The FIQR, FASmod, and PSD scores were significantly reduced at 24 months. The pain magnification domain score of the PCS was the only variable predictive of worse FIQR scores (Wald coefficient: -2.94; p = 0.047). These results suggest a potential long-term therapeutic role for the PEA + ALC combination, with pain magnification being the primary predictor of poor efficacy.

Ultramicronized N-palmitoylethanolamine associated with analgesics: Effects against persistent pain

Current epidemiological data estimate that one in five people suffers from chronic pain with considerable impairment of health-related quality of life. The pharmacological treatment is based on first- and second-line analgesic drugs, including COX-2 selective and nonselective nonsteroidal anti-inflammatory drugs, paracetamol, antidepressants, anti-seizure drugs and opioids, that are characterized by important side effects. N-palmitoylethanolamine (PEA) is a body's own fatty-acid ethanolamide belonging to the family of autacoid local injury antagonist amides. The anti-inflammatory and pain-relieving properties of PEA have been recognized for decades and prompted to depict its role in the endogenous mechanisms of pain control. Together with its relative abundance in food sources, this opened the way to the use of PEA as a pain-relieving nutritional intervention. Naïve PEA is a large particle size lipid molecule with low solubility and bioavailability. Reducing particle size is a useful method to increase surface area, thereby improving dissolution rate and bioavailability accordingly. Micron-size formulations of PEA (e.g., ultramicronized and co-(ultra)micronized) have shown higher oral efficacy compared to naïve PEA. In particular, ultramicronized PEA has been shown to efficiently cross the intestinal wall and, more importantly, the blood-brain and blood-spinal cord barrier. Several preclinical and clinical studies have shown the efficacy, safety and tolerability of ultramicronized PEA. This narrative review summarizes the available pharmacokinetic/pharmacodynamic data on ultramicronized PEA and focuses to its contribution to pain control, in particular as 'add-on' nutritional intervention. Data showing the ability of ultramicronized PEA to limit opioid side effects, including the development of tolerance, have also been reviewed.

The Pharmacological Treatment of Chronic Pain: From Guidelines to Daily Clinical Practice

In agreement with the International Association for the Study of Pain, chronic pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage. To date, there are several types of pain: nociceptive, neuropathic, and nociplastic. In the present narrative review, we evaluated the characteristics of the drugs used for each type of pain, according to guidelines, and their effects in people with comorbidity to reduce the development of severe adverse events.

Effects of Palmitoylethanolamide (PEA) on Nociceptive, Musculoskeletal and Neuropathic Pain: Systematic Review and Meta-Analysis of Clinical Evidence

Some 30−50% of the global population and almost 20% of the European population actually suffer from chronic pain, which presents a tremendous burden to society when this pain turns into a disability and hospitalization. Palmitoylethanolamide (PEA) has been demonstrated to improve pain in preclinical contexts, but an appraisal of clinical evidence is still lacking. The present study aimed at addressing the working hypothesis for the efficacy of PEA for nociceptive musculoskeletal and neuropathic pain in the clinical setting. The systematic search, selection and analysis were performed in agreement with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 recommendations. The primary outcome was pain reduction, as measured by a pain assessment scale. The secondary outcome was improvement in quality of life and/or of parameters of function. The results obtained for a total of 933 patients demonstrate the efficacy of PEA over the control (p < 0.00001), in particular in six studies apart from the two randomized, double-blind clinical trials included. However, the results are downgraded due to the high heterogeneity of the studies (I2 = 99%), and the funnel plot suggests publication bias. Efficacy in achieving a reduction in the need for rescue medications and improvement in functioning, neuropathic symptoms and quality of life are reported. Therefore, adequately powered randomized, double-blind clinical trials are needed to deepen the domains of efficacy of add-on therapy with PEA for chronic pain. PROSPERO registration: CRD42022314395.