Pilot Study of Levetiracetam (Keppra® (Registered Trademark)) for Bipolar Illness

Overview

This study will explore the possible effectiveness of levetiracetam in patients with bipolar illness who have not responded adequately to standard treatments. Levetiracetam was recently approved to treat seizures. Other drugs in the same class as levetiracetam, including carbamazepine and valproate, are widely recognized as substitute medications for lithium or are used as an adjunct to it, and other anticonvulsants have also shown promise in improving bipolar symptoms. Patients with bipolar illness whose manic, depressed or unstable moods are not adequately controlled by their current treatment and who have not responded previously to two standard treatments (i.e., lithium, valproate, carbamazepine or neuroleptics) may be eligible for this study. Participants will take levetiracetam starting at 500 mg daily. If this dose is well tolerated, it will be increased to 500 mg twice a day. Every 3 days, doses may be increased until the target dose of 3000 mg/day is reached. Higher doses, not to exceed 4000 mg/day, may be tried in patients who do not respond fully to the lower doses. Patients and observers will use standard ratings to evaluate the patients' response to therapy during the 8-week study. If, after 8 weeks, the results appear promising, patients may continue treatment for an additional 6 months to evaluate longer-term effects.

Almost all of the approved anticonvulsant compounds (with the exception of gabapentin and tiagabine) have now been suggested to have acute antimanic or more long-term mood stabilizing properties. Carbamazepine and valproate have gained a widely recognized role in treatment algorithms of bipolar illness, and lamotrigine has shown promising antidepressant effects. Levetiracetam (Keppra® (Registered Trademark)) is the most recently approved anti-epileptic drug available, and deserves pilot exploration in bipolar illness for a variety of reasons. These include: its positive side-effects profile; it is a derivative of the nootropic agent piracetam which has memory-enhancing properties in animal studies; it likely has a unique mechanism of action since it is not active on most of the traditional excitatory and inhibitory neurotransmitter systems; it is not active on traditional anticonvulsant models such as pentylenetetrazol (PTZ) or maximum electroshock (MES) seizures, but is able to stop both the development and completed phase of amygdala-kindled seizures; and it is not metabolized by hepatic enzymes and thus has few adverse pharmacokinetic interactions. We propose pilot exploration of levetiracetam as an adjunctive agent in patients with bipolar illness who are inadequately responsive to routine psychopharmacological agents for bipolar illness. At the NIMH we will study a maximum of 10 acutely depressed, 10 manic, and 10 cycling patients enrolled in Protocol 97-M-0039. We would start at Levetiracetam doses of 500 mg/day, and not to exceed 4000 mg/day. Response will be based primarily on the percentage of patients showing "much" or "very much" improvement on the GCI-BP score in each of the three groups as augmented by the percentage decrement on cross-sectional scales such as the Inventory of Depressive Symptomatology (IDS) and Young Mania Rating Scale (YMRS) in conjunction with prospective ratings on the NIMH-LCMp. Should preliminary evidence of efficacy be observed in this open add-on clinical trial, more systematic controlled studies will then be designed for confirmation of promising target areas of efficacy.