Efficacy and safety of carisbamate in patients with diabetic neuropathy or postherpetic neuralgia: results from 3 randomized, double-blind placebo-controlled trials.

Abstract

The results of 3 proof-of-concept studies to evaluate carisbamate's efficacy and safety in treating neuropathic pain are presented. In studies 1 (postherpetic neuralgia, n = 91) and 2 (diabetic neuropathy, n = 137), patients received carisbamate 400 mg/day or placebo for 4 weeks and then crossed over to the other treatment for 4 weeks. In study 3 (diabetic neuropathy, higher carisbamate doses), patients (n = 386) were randomized (1:1:1:1) to receive either carisbamate 800 mg/day, 1200 mg/day, pregabalin 300 mg/day or placebo for 15 weeks. Primary efficacy end point was the mean of the last 7 average daily pain scores obtained on days the study drug was taken, for all 3 studies. Least square mean (95% CI) differences between carisbamate and placebo groups on the primary end point were as follows: study 1: -0.512 (-1.32, 0.29) carisbamate 400 mg/day; study 2: -0.307 (-0.94, 0.33) carisbamate 400 mg/day; and study 3: -0.51 (-1.10, 0.08), carisbamate 800 mg/day; -0.55 (-1.13, 0.04), carisbamate 1200 mg/day; and -0.43 (-1.01, 0.15), pregabalin 300 mg/day. Neither carisbamate (all 3 studies) nor pregabalin (study 3) significantly differed from placebo, although multiple secondary end points showed significant improvement in efficacy with carisbamate in studies 1 and 2. Dizziness was the only treatment-emergent adverse event occurring at ≥10% difference in carisbamate groups versus placebo (study 1: 12% vs. 1%; study 3: 14% vs. 4%; study 2: 1% vs. 2%). Carisbamate, although well tolerated, did not demonstrate efficacy in neuropathic pain across these studies, nor did the active comparator pregabalin (study 3).

• Authors: Timothy Smith, Allitia DiBernardo, Yingqi Shi, Mike J Todd, H Robert Brashear, Lisa M Ford
• Journal: Pain practice : the official journal of World Institute of Pain (Pain Pract) Vol. 14 Issue 4 Pg. 332-42 (Apr 2014) ISSN: 1533-2500 [Electronic] United States
• PMID: 23692321 (Publication Type: Journal Article, Multicenter Study, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)
• Copyright: © 2013 World Institute of Pain.

Chemical References

• Carbamates
• Neurotransmitter Agents
• S-2-O-carbamoyl-1-o-chlorophenyl-ethanol

Topics

• Adolescent
• Adult
• Aged
• Aged, 80 and over
• Carbamates (therapeutic use)
• Diabetic Neuropathies (drug therapy)
• Double-Blind Method
• Female
• Follow-Up Studies
• Humans
• Male
• Middle Aged
• Neuralgia, Postherpetic (drug therapy)
• Neurotransmitter Agents (therapeutic use)
• Pain Measurement
• Severity of Illness Index
• Treatment Outcome
• Young Adult