Original ArticlesDose-Response Study of the Analgesic Effect of Lanepitant in Patients with Painful Diabetic NeuropathyGoldstein, David J.*†; Wang, Ouhong; Gitter, Bruce D.; Iyengar, SmritiAuthor Information Department of Neuroscience Research, Lilly Research Laboratories; *Department of Pharmacology and Toxicology, Indiana University School of Medicine; and †Department of Pediatrics, Methodist Hospital, Indianapolis, Indiana, USA Address correspondence and reprint requests to David J. Goldstein, Lilly Research Laboratories, Lilly Corporate Center, Indianapolis, IN 46285, USA. This work was sponsored by Eli Lilly and Company. Clinical Neuropharmacology: January-February 2001 - Volume 24 - Issue 1 - p 16-22 Buy Abstract Lanepitant is effective in the formalin analgesic model suggesting efficacy in painful neuropathy. This study was designed to evaluate the dose-response effect of lanepitant in patients with daily moderate to severe, bilateral, distal neuropathic pain. After a 1-to 3-week lead-in period, patients were randomly allocated to double-blind, parallel treatment with lanepitant 50 mg daily (n = 27), 100 mg daily (n = 27), 200 mg twice daily (n = 13), or placebo (n = 26) over 8 weeks. Patients reported average daytime pain and average nighttime pain intensity. Plasma concentrations and amount of adjunctive analgesic medication were obtained at all visits after baseline. Patient global evaluation and clinician global impression were obtained at weeks 3 and 8. Safety was assessed by adverse events, vital signs, laboratory analytes, and electrocardiogram. No dosage of lanepitant differed significantly from placebo. Efficacy did not increase with lanepitant dosage, and higher plasma concentrations were no more effective than lower plasma concentrations. The adverse event diarrhea was more frequent for lanepitant-treated patients. Although well tolerated, lanepitant was ineffective in relieving pain of diabetic neuropathy. © 2001 Lippincott Williams & Wilkins, Inc.