Valproate: Not All Boxed Warnings Are Created Equal.

Abstract

Valproate has undergone significant changes in labeling to the boxed warnings associated with it. This review will analyze evidence regarding the valproate-boxed warnings for teratogenicity, hepatotoxicity, and pancreatitis, with a particular emphasis on the fetal risk. A review of Pubmed, Cochrane Central Register, Google Scholar, manufacturer websites, and product labeling was performed from 1963 to February 2022, using the following search terms: valproate, valproic acid, depakote, teratogenicity, birth defects, fetal risk, hepatotoxicity, and pancreatitis. Relevant English-language studies and those conduced in humans were considered. Product labeling was also reviewed. There is a significant fetal risk following in utero valproate exposure (risk of malformation development: 8.6% in 360 women in North America). Current labeling in the United States recommends co-prescribing effective contraception for women of childbearing age. The risk of hepatotoxicity and pancreatitis is much lower in the general population (1/20 000 and 1/40 000 patients, respectively) compared with those patients with certain risk factors who are taking valproate (1/500). Overstated monitoring recommendations for the potential risk of hepatotoxicity and pancreatitis distracts from a much more common and severe risk of fetal harm. Clinicians must be diligent about discussing this risk with patients and documenting when this discussion occurs. Changes to the current recommendations for monitoring of the boxed warnings associated with valproate therapy should be considered, such as more stringent monitoring requirements for the inherent fetal risk. This could be accomplished through a Risk Evaluation and Mitigation Strategy program or through institution-based policies and procedures. In addition, monitoring recommendations for the risk of hepatotoxicity and pancreatitis should account for contributing risk factors.