Oxcarbazepine use in essential tremor.

OBJECTIVE: To report the novel finding of a significant improvement in essential tremor symptoms with oxcarbazepine in a patient with a suboptimal response to propranolol. CASE SUMMARY: A 40-year-old woman with a history of substance abuse complicated by essential tremor and neuropathic pain was admitted to our addictions unit with altered mental state due to escalating use of alprazolam. Alprazolam had been prescribed several months prior to admission for treatment of anxiety. The doses had risen to 5-10 mg/day during that period. Apparently, her essential tremor had responded inadequately to propranolol, but had responded well to alprazolam. She was started on a sedative/hypnotic withdrawal protocol, but did not require treatment with phenobarbital. She subsequently rated her tremor as, 'moderately severe." On discontinuation of the withdrawal protocol, oxcarbazepine 450 mg twice daily was initiated to treat her neuropathic pain, and the tremor improved, with a clinically significant reduction in tremor and a decreased pain score. DISCUSSION: Essential tremor is a common neurologic disorder with uncertain pathophysiology. Practice guidelines advocate the use of propranolol or primidone as first-line agents to treat essential tremor. Unfortunately, primidone has abuse potential and propranolol has variable pharmacokinetics; these characteristics limit their effectiveness in treating tremor. Our patient experienced a significant and sustained improvement in her tremor following the initiation of oxcarbazepine. To our knowledge, as of September 2, 2006, this is the first report of the use of oxcarbazepine in essential tremor. While the exact therapeutic action remains unclear, oxcarbazepine offers significant advantages compared with current first-line agents, including its good tolerability profile, the extended half-life of its metabolite, and lack of abuse potential. CONCLUSIONS: We report a case of essential tremor responding to oxcarbazepine. This drug offers several potential advantages over current first-line agents. Further research is warranted to test the robustness of this preliminary finding.