Objective: Lithium (Li) reduces disease activity in animal models of multiple sclerosis (MS), but has not been previously studied in human MS. While developing a clinical trial to test the effects of Li in MS, we performed a retrospective chart review to determine the safety and tolerability of Li among US veterans with MS.
Methods: We identified all veterans with MS prescribed Li from 1998 to 2009 using the Department of Veterans Affairs Pharmacy Benefits Management. Charts were reviewed for Li-related adverse events and effects on the MS disease course.
Results: Among 21,847 veterans with MS, 101 met inclusion criteria and took Li ≥6 months. Eighteen percent of subjects experienced a Li-associated adverse event. Later age of MS onset was associated with increased risk of Li-related adverse events (p=0.004). Associations between Li use and MS disease activity were mixed: Li was not associated with increased risk of enhancing MRI lesions (p=0.655), but annualized relapse rates were higher on Li (0.34 vs. 0.20, p=0.044). In contrast, change in Expanded Disability Status Scale scores was greater in the off-Li period than the on-Li period (0.8 vs. 0.3, p=0.003).
Conclusion: Adverse events occur in a minority of Li-treated MS patients. A consistent effect of Li on MS disease activity was not apparent. These findings indicate a clinical trial will be needed to ascertain Li's effects on the MS disease course.
Keywords: Drug tolerance; Drug toxicity; Lithium; Multiple sclerosis; Retrospective study; Veteran.
Published by Elsevier B.V.