Valpros Pedia Drug Interactions

Caution is advised when using sodium valproate together with newer antiepileptics whose pharmacodynamics may not be well established.
Sodium valproate is an inhibitor of a variety of hepatic enzymes, including cytochrome P450, glucuronyl transferase and epoxide hydrolase. The following drug interactions are not exhaustive, as new interactions may be reported. (See table.)

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Laboratory Test Alterations: Sodium valproate is excreted mainly through the kidneys, partly in the form of ketone bodies. This may give false positives in the urine testing of possible diabetics.
Altered thyroid function test results (including both hyperthyroidism and hypothyroidism) have been associated with sodium valproate. The clinical significance of this is unknown.
In vitro studies suggest that valproate stimulates the replication of the human immunodeficiency virus (HIV) and cytomegalovirus (CMV) viruses under certain experimental conditions. However, the clinical consequence is not yet known. However, these data should be considered when interpreting the results from regular monitoring of the viral load in HIV infected patients taking sodium valproate or when following CMV infected patients clinically.
Protein binding of valproate is reduced in the elderly, in patients with renal impairment, and in the presence of other drugs (e.g., Aspirin). Accordingly, measurements of plasma levels of valproate may be misleading in these patients; an actual drug exposure may be higher than measured values.
Decreased coagulation factors (at least one), abnormal coagulation tests (e.g., prolonged prothrombin time, activated partial thromboplastin, prolonged thrombin time, prolonged INR).