Benfotiamine might help diabetic neuropathy. It activates transketolase in the pentose phosphate pathway. This could protect nerves from high blood sugar. Doctors hoped it would work long-term. Researchers tested this idea. They ran a 1:1 randomized double-blind trial. It was placebo-controlled. The study happened at one center. They treated type 2 diabetes patients with mild-to-moderate DSPN. Patients took benfotiamine 300 mg two times per day. Or they got placebo. Treatment lasted 12 months. The study was published in the BMJ Open Diabetes Research and Care.
Primary Endpoint Shows No Effect
Primary endpoint was change in corneal nerve fiber length. Doctors measured this with corneal confocal microscopy. Changes from baseline to 12 months were the same in both groups. Benfotiamine did not work better than placebo.
Secondary Measures Confirm Negative Results
Secondary endpoints covered many tests. These included three other CCM parameters. Skin biopsy had four measures. Nerve conduction studies used 13 measures. Quantitative sensory testing had six parameters. Cardiovascular autonomic tests included 17 indices. Sudomotor tests had five parameters. Clinical scores numbered 15 for symptoms and signs. Quality of life tools totaled 13. Depression instruments also numbered 13. All showed similar changes between groups.
Only Symptom Score Improved Slightly
Neuropathy Symptom Score showed a trend. It improved more with benfotiamine. P-value was 0.098 versus placebo. This did not reach significance. Other outcomes stayed neutral.
Drug Was Safe But Ineffective
Benfotiamine raised all six thiamine blood levels. Each showed p≤0.003 versus placebo. Safety was good. Adverse event rates matched between groups.
Time to Remove Benfotiamine from Protocols
Neurologists should stop benfotiamine for DSPN. Trial used rigorous endpoints like CCM. It tested morphometric and functional measures. Clinical scales also failed to show benefit. Focus shifts to approved therapies. Pathophysiology research must continue.