The present study investigated the benefits of adding coenzyme Q10 (CoQ10) to Pregabalin in improving painful diabetic neuropathy (PDN) symptoms.

It randomized one hundred twelve patients with PDN to receive either CoQ10 + Pregabalin (57 patients) or placebo + Pregabalin (55 patients). Along with Pregabalin (150 mg/day), the patients received CoQ10 100 mg every eight hours or matched placebo for eight consecutive weeks depending upon the groups assigned. 

The study measured efficacy as the changes in the pain intensity from baseline to endpoint measured on an 11-point NRS (numeric rating scale) along with the changes in the pain-associated sleep interference score (SIS) and the patients global improvement with treatment measured on the Clinicians and Patients Global Impression of Change (CGIC/PGIC).

On the intent-to-treat population (ITT) analysis, the study found the CoQ10 + pregabalin regimen caused a significantly greater pain relief than the placebo + pregabalin regimen. By the end of week 2, both the groups showed a similar decrease in the mean pain NRS score, but by the end of weeks four and eight, patients taking CoQ10 + Pregabalin showed a greater reduction in the mean pain NRS score than those taking placebo + Pregabalin. Likewise, by the end of week 8, the patients supplemented with CoQ10 showed a more significant decrease in the pain-associated SIS compared to the placebo. Furthermore, the proportion of the responder patients (those having ≥ 50% decline in the mean pain NRS score) and the proportion of patients rating "very much" or "much improved" on the CGIC/PGIC scales also significantly increased in the CoQ10 + pregabalin-treated patients than placebo + pregabalin-treated patients.

This study shows that diabetic patients suffering from PDN may benefit from using antioxidant and anti-inflammatory supplements like CoQ10 along with Pregabalin. 

Amini P, Sajedi F, Mirjalili M, et al. Coenzyme Q10 as a potential add-on treatment for patients suffering from painful diabetic neuropathy: results of a placebo-controlled randomized trial. Eur J Clin Pharmacol. 2022;78: 1899–1910. https://doi.org/10.1007/s00228-022-03407-x