Efficacy of oxcarbazepine in the treatment of painful diabetic neuropathy.
OBJECTIVE
To evaluate the safety, tolerability, and efficacy of oxcarbazepine in the treatment of painful diabetic neuropathy.


METHODS
This was an open-label, 9-week trial, consisting of a 1-week prospective Screening Phase followed by an 8-week Treatment Phase. Treatment with oxcarbazepine was initiated at 150 mg/day, and the daily dose was doubled on a weekly basis and titrated to tolerability over 4 weeks, up to 1200 mg/day. This was followed by a 4-week fixed-dose Maintenance Phase, during which patients were maintained on oxcarbazepine at 1200 mg/day or highest tolerated dose. The primary efficacy variable was the change in the weekly pain rating assessed on the Visual Analog Scale (VAS) of the short-form McGill Pain Questionnaire between the Screening Phase and the Treatment Phase. All analyses were performed on the intent-to-treat population.


RESULTS
Thirty patients were enrolled in the trial. The mean daily oxcarbazepine dose during the Maintenance Phase was 814 mg. The mean VAS score dropped from 66.3 during the Screening Phase to 34.3 at the end of the trial (P = 0.0001), for a mean reduction of 48.3%. In addition, there were significant improvements in the total pain score and present pain intensity. Oxcarbazepine was well tolerated, with the most common adverse events consisting of drowsiness and dizziness.


CONCLUSIONS
The results suggest that oxcarbazepine administered as monotherapy is an efficacious and safe option for the symptomatic treatment of pain associated with symmetrical diabetic neuropathy. These results will need to be confirmed in large, double-blind, placebo-controlled, randomized clinical trials.
Beydoun
Ahmad
A
University of Michigan Health System, Ann Arbor, Michigan 48109-0036, USA. beydoun@umich.edu
Kobetz
Steven A
SA
Carrazana
Enrique J
EJ
D000328:Adult; D000368:Aged; D000927:Anticonvulsants / Q000009:adverse effects / Q000627:therapeutic use; D002220:Carbamazepine / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use*; D003929:Diabetic Neuropathies / Q000150:complications / Q000188:drug therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000078330:Oxcarbazepine; D010146:Pain / Q000188:drug therapy* / Q000209:etiology; D010147:Pain Measurement / Q000187:drug effects; D011795:Surveys and Questionnaires; D013997:Time Factors; D016896:Treatment Outcome
D000927:Anticonvulsants; D002220:Carbamazepine; D000078330:Oxcarbazepine