Critically ill patients are at high risk of developing thrombocytopenia with an incidence ranging between 14–44% for patients admitted to the intensive care unit. In addition, those patients had significantly higher ICU mortality and required longer mechanical ventilation. Thrombocytopenia may be a side effect of valproate, with risk factors including advanced age, female gender, lower baseline platelet counts, and increased plasma valproate levels. Increased free valproate fraction (which may be relevant in critically ill patients) may also be correlated with decreased platelet count.

Publication reference : Nasreddine W et al. Predicting the occurrence of thrombocytopenia from free valproate levels: A prospective study. Seizure 2022; 94: 33-38
Reference URL: https://pubmed.ncbi.nlm.nih.gov/34864249/