Use of topiramate, a new anti-epileptic as a mood stabilizer.

RATIONALE: Because some anti-epileptic drugs (AEDs) are effective in bipolar affective disorders, the new AED topiramate (TPM) may be effective in psychiatric illnesses. TPM was evaluated in mood disorders refractory to previous therapies including newer AEDs.

METHODS: Charts of 58 consecutive patients, 39 outpatients (15 males, 24 females) and 19 inpatients (6 males, 13 females) were reviewed. TPM 25 mg. b.i.d. was added to existing therapy and titrated in 50 mg increments every 3-7 days. Improvement was rated on a Likert global assessment scale of marked, moderate, mild, or no improvement or worse, based on quality of sleep, appetite, mood, and concentration.

RESULTS: Of the 58 patients with psychiatric disorders, 44 patients had rapid cycling bipolar disorders characterized by manic, hypomanic, or mixed episodes. Eighteen patients had previously failed to respond to lamotrigine and/or gabapentin in addition to conventional mood stabilizers. Fourteen were Bipolar I, six Bipolar II, and seven mixed, ten patients had cyclothymic disorder, seven had bipolar disorder not otherwise specified. Of the remaining 14 patients, nine had schizoaffective disorder, three patients had dementia and two had psychosis. Mean duration of TPM treatment was 16.0 weeks; mean TPM dosage approximately 200 mg/day. Thirty-six of 58 (62%) patients exhibited marked or moderate improvement, usually within days or weeks. Twenty-three of 44 (52%) patients with bipolar affective disorders showed marked or moderate improvement. Minimal/no improvement was observed in 16; six were rated as worse. Adverse events included delirium in one patient with Bipolar Disorder Type I who overmedicated with TPM (800 mg) and tranylcypromine sulfate (170 mg) combined with alcohol. Other adverse effects were minor and included: paresthesias, somnolence, fatigue, impaired concentration and memory, nausea, and diarrhoea.

LIMITATIONS: This study was performed in a nonrandom open and retrospective fashion. Therefore, any findings are limited by the design of this study.

CONCLUSION: TPM may be useful in patients with mood disorders unresponsive to traditional therapy and warrants further clinical investigation.