Effect of Rivastigmine (Acetyl Cholinesterase Inhibitor) versus Placebo on Manic Episodes in Patients with Bipolar Disorders: Results from a Double Blind, Randomized, Placebo-Controlled Clinical Trial

Abstract

Background: To treat patients with bipolar disorders (BPD) during the acute phase, the standard procedure is to administer lithium or sodium valproate. To further optimize treatment, acetylcholinesterase inhibitors such as donepezil and galantamine have gained increased interest, though with conflicting results. In the present randomized, double-blind, placebo-controlled clinical trial, we investigated whether, and to what extent, adjuvant rivastigmine might improve symptoms of mania in patients with BPD during the acute manic phase. Methods: A total of 70 patients with BPD in an acute state of mania (mean age 33.8 years; 24% females) took part in this study. After a thorough clinical interview, standard treatment consisted of 20mg/kg/day of sodium valproate; next, patients were randomly assigned either to the adjuvant rivastigmine or to the placebo condition. The study duration was 24 days. The dose of rivastigmine was 1.5 mg for the first 7 days and 3 mg from day 8 to day 24. Experts blind to the patients’ study condition rated patients’ mania scores, symptom severity, and symptom improvements at baseline (except symptom improvements) and 4, 8, 12, and 24 days after the beginning of this study. Results: Symptoms of mania improved over time, but more so in the adjuvant rivastigmine compared to the placebo condition. Greater improvements were observed from day 8 on. Conclusions: The pattern of results from the present randomized, placebo-controlled, double-blind study suggests that adjuvant rivastigmine, a cholinesterase inhibitor, improved symptoms of mania among a larger sample of inpatients with BPD and in the acute manic state. However, the improvements were modest, and the results should be replicated and above all balanced against side effects.