Pleural Effusion Associated With Divalproex Sodium

A 19-year-old male developed bilateral pleural effusion and persistent fever after taking divalproex sodium for bipolar disorder, which resolved upon discontinuation of the drug. A review of 18 published cases of valproic acid-associated pleural effusion showed that this condition can occur with varying dosages and durations of treatment. The effusion was often eosinophilic, though the present case was lymphocytic. The study suggests that divalproex sodium may cause pleural effusion, and clinicians should consider discontinuing the drug if unexplained pleural effusion occurs. Further research is needed to determine safe dosage levels and the relationship between drug concentration and pleural effusion severity.