@article{96699e11655140488f2088c0587cb113,
title = "Thrombocytopenia in pediatric patients on concurrent cannabidiol and valproic acid",
abstract = "In January 2019, a new plant-derived purified cannabidiol preparation, approved by the US Food and Drug Administration, became commercially available for patients ≥2 years old with Lennox-Gastaut syndrome or Dravet syndrome. Among our patients who were prescribed the new cannabidiol formulation, we observed several cases of thrombocytopenia and therefore embarked on this study. We conducted a single-center systematic chart review of all pediatric patients (<21 years old) who were prescribed cannabidiol from January to August 2019. We evaluated salient features of the patients{\textquoteright} epilepsy syndrome, age, concurrent medications, and surveillance laboratory results before and after cannabidiol initiation. Among 87 patients, nine (10%) developed thrombocytopenia (platelet nadir range = 17 000-108 000) following initiation of cannabidiol. Each of these nine children was on combination therapy of cannabidiol with valproic acid. Whereas no children on cannabidiol without valproic acid (0/57) developed thrombocytopenia, nine of 23 treated with combination valproic acid and cannabidiol developed platelets < 110 000/µL (P <.0001). We report a novel and clinically important side effect of thrombocytopenia in one-third of patients treated concurrently with cannabidiol and valproic acid. If this finding is confirmed, clinicians should perform close monitoring for thrombocytopenia when adding cannabidiol to a regimen that includes valproic acid.",
keywords = "cannabidiol, Dravet syndrome, intractable epilepsy, Lennox-Gastaut syndrome",
author = "McNamara, {Nancy A.} and Dang, {Louis T.} and Julie Sturza and Ziobro, {Julie M.} and {Fedak Romanowski}, {Erin M.} and Smith, {Garnett C.} and Joshi, {Sucheta M.} and Leber, {Steven M.} and Martha Carlson and Patricia Robertson and Shellhaas, {Ren{\'e}e A.}",
note = "Funding Information: This work was supported by the University of Michigan Charles Woodson Pediatric Research Fund. Funding Information: This work was supported by the University of Michigan Charles Woodson Pediatric Research Fund. The authors thank Stephanie Rau, CCRP, and Shannon Lester-Pelham, CCRP, for their help with this project. They are also grateful to their colleagues in the Michigan Medicine Department of Pediatrics, Division of Hematology-Oncology (Kelly Walkovich and David Frame). Funding Information: R.A.S.'s research is supported by the National Institutes of Health (NIH), Patient‐Centered Outcomes Research Institute, the Pediatric Epilepsy Research Foundation, and the University of Michigan, receives royalties from UpToDate for authorship of topics related to neonatal seizures, and has served as a consultant for the Epilepsy Study Consortium. L.T.D.'s research is supported by the NIH (NS 109 289), the Child Neurology Society/Foundation, and the University of Michigan. J.M.Z. is a site principal investigator and L.T.D. is a coinvestigator for the BUTTERFLY Study, a research contract from Stoke Therapeutics. None of the other authors has any conflict of interest to disclose. We confirm that we have read the Journal's position on issues involved in ethical publication and affirm that this report is consistent with those guidelines. Publisher Copyright: {\textcopyright} 2020 International League Against Epilepsy",
year = "2020",
month = aug,
day = "1",
doi = "10.1111/epi.16596",
language = "English",
volume = "61",
pages = "e85--e89",
journal = "Epilepsia",
issn = "0013-9580",
number = "8",
}