IRCT20120215009014N385 IRCT 2021-02-21 Hamedan University of Medical Sciences Effect of coenzyme Q10 versus placebo as an adjuvant therapy on pain in patients with painful diabetic neuropathy Effect of coenzyme Q10 versus placebo as an adjuvant therapy on pain in patients with painful diabetic neuropathy: a double-blind randomized clinical trial 2021-05-05 anticipated 116 Complete https://irct.ir/trial/54450 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Used, Assignment: Parallel, Purpose: Treatment, Randomization description: The patients will be randomly assigned to intervention and control groups using block randomization. For this purpose, we will prepare four sheets of paper, writing on two sheets the name of the intervention and on the other two sheets the name of the control. The paper sheets will be pooled, placed in a container, and randomly drawn one at a time for each patient without replacement until all four sheets are drawn. The four paper sheets will be then placed back into the container, and this action repeated until the sample size is reached, Blinding description: The shape of the medications and placebos will be perfectly the same. Therefore, patients will be unaware of the type of intervention. The physician who will examine the patients will not be aware of the intervention. Thus, the trial will be run as double-blind. 3 Painful diabetic neuropathy. Intervention 1: Intervention group: Pregabalin tablet 75 mg (manufactured by Golden Life Pharmaceutical Co.) every 12 hours for 8 weeks plus coenzyme tablet Q10 100 mg (manufactured by Reyhaneh Pharmaceutical Co.) every 8 hours for 8 weeks. Intervention 2: Control group: Pregabalin tablet 75 mg (manufactured by Golden Life Pharmaceutical Co.) every 8 hours for 8 weeks plus placebo tablet including starch (manufactured by laboratory of School of Pharmacy, Hamadan) every 12 hours for 8 weeks. Undecided - It is not yet known if there will be a plan to make this available Justification or reason for indecision in sharing IPD is It depends on the situations and the results of the study as well as the approval of the financial supporting organization.