Lack of effect of clonidine and pentoxifylline in short-term therapy of diabetic peripheral neuropathy

The goal of this study was to confirm or rule out anecdotal reports of beneficial effects of clonidine and pentoxifylline in the treatment of painful diabetic peripheral neuropathy. Clonidine was administered to 16 subjects at two dosage levels (0.1 and 0.2 mg/day) and was compared to placebo in a crossover design, with each phase lasting 4 wk. Either pentoxifylline (400 mg 3 times/day) or placebo was given to 21 subjects in a 12-wk trial. Discomfort was characterized and rated with a subjective pain score (range 0-20). There was a significant decrease in pain score from baseline with both active drugs (P less than 0.05), but this was no better than the response to placebo (P less than 0.30 for clonidine and P less than 0.95 for pentoxifylline). This study does not demonstrate a short-term benefit of either clonidine or pentoxifylline in the treatment of peripheral neuropathy.