Nortriptyline-fluphenazine vs. carbamazepine in the symptomatic treatment of diabetic neuropathy.

We compared the efficacy and tolerance of the combination of nortriptyline-fluphenazine (NF) vs. carbamazepine (CMZ) in the symptomatic therapy of patients with severe, distal, symmetrical, predominantly sensitive diabetic polyneuropathy (DPN). We followed a double blind, crossover, randomized and double placebo design. Sixteen patients with severe DPN participated in the study. Patients received either NF (1 tablet three times a day (tid)), for 2 weeks and 2 tablets tid for the next 2 weeks or CMZ 1/2 tablet tid for 2 weeks and 1 tablet tid for the next 2 weeks. After this, patients received placebos of both drugs (wash-out period), until symptoms returned to baseline levels (100%), then they were crossed over to receive the other comparing drug schedule. A visual analogue scale was used to evaluate the percent changes in pain and paresthesia. HbA1, fasting serum glucose, and safety tests were performed at 2- and 4-week intervals, respectively. Both therapies produced significant improvement of both pain and paresthesia. No statistically significant differences were observed between both therapies for either pain or paresthesia. No significant biochemical changes were observed with any of the two therapies. Side effects were mild and more frequent in the NF period. In this study no superiority of either drug schedule was demonstrated; therefore, the decision to use any of them should be made according to the associated pathology and potential side effects of each drug.