A Controlled Trial of Sorbinil, an Aldose Reductase Inhibitor, in Chronic Painful Diabetic Neuropathy

A double-blind, randomized, placebo-controlled crossover trial of the aldose reductase inhibitor sorbinil was undertaken in 15 patients (age 35–68 yr) with chronic painful diabetic neuropathy. Treatment was evaluated by subjective pain responses, clinical examination, vibration perception threshold, motor and sensory nerve electrophysiology, and cardiovascular reflex tests of autonomie nerve function. Among the many measurements, only pain, tendon reflex scores, and sural sensory potential amplitude improved significantly during sorbinil administration, while scores of clinical sensory examination deteriorated. Four patients experienced an idiosyncratic reaction that rapidly recovered on discontinuing the drug. This study suggests that aldose reductase inhibitor treatment with sorbinil may have an effect on symptomatic diabetic neuropathy in man.