A blinded, randomized comparison of immediate-release and extended-release carbamazepine capsules in manic and depressed bipolar subjects.
BACKGROUND
The anticonvulsant carbamazepine is approved by the FDA for treatment of acute mania. It is available in 2 formulations: immediate-release (IR) and extended-release carbamazepine capsules (ERCC). The relative efficacy of these formulations in acutely ill bipolar patients has not been previously investigated.


METHODS
This study is a subanalysis of a 3-month, blinded, equal, random-assignment comparison of adverse effect load of an IR carbamazepine formulation (Tegretol) and ERCC (Equetro) in type I or type II bipolar patients already receiving carbamazepine or clinically determined to benefit from carbamazepine treatment. Dosages were titrated to patients' clinical needs. Subjects who scored >15 on the Montgomery Asberg Depression Rating Scale (MADRS) or >14 on the Young Mania Rating Scale (YMRS) were included in this analysis. The primary outcome measures were the relative mood scores at the end of the study.


RESULTS
At the end of 3 months of treatment, all patients improved compared with their baseline, but there was no difference in mood ratings in subjects with an initial MADRS >15 (ERCC, 18.2 +/- SD 11.9, vs IR, 12.0 +/- 4.5; P = .3) or YMRS >15 (ERCC, 6.5 +/- 6.4, vs IR, 4.7 +/- 3.1; P = .7). When compared with their baseline, patients receiving IR improved earlier than patients receiving ERCC. There were no differences in overall adverse events in patients receiving IR or ERCC (23.1 +/- 13.42 vs 22.3 +/- 13.40; P = .9).


CONCLUSIONS
Carbamazepine is effective in treating symptoms of both mania and depression, and there are no significant differences in the relative efficacy of the IR or ERCC formulations.
El-Mallakh
Rif S
RS
Mood Disorders Research Program, Department of Psychiatry and Behavioral Sciences, University of Louisville School of Medicine, Louisville, KY 40202, USA. rselma01@louisville.edu
Salem
Mary Ruth
MR
Chopra
Amarjit
A
Mickus
Gregory J
GJ
Penagaluri
Praveen
P
Movva
Radhika
R
D000328:Adult; D018692:Antimanic Agents / Q000008:administration & dosage*; D001714:Bipolar Disorder / Q000188:drug therapy* / Q000523:psychology; D002214:Capsules; D002220:Carbamazepine / Q000008:administration & dosage*; D003692:Delayed-Action Preparations / Q000627:therapeutic use; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D016896:Treatment Outcome
D018692:Antimanic Agents; D002214:Capsules; D003692:Delayed-Action Preparations; D002220:Carbamazepine