[Acute pancreatitis induced by valproic acid]

We describe the case of an adult man aged 49, without personal antecedents, or family psychiatric history, treated for bipolar disorder since 1995 and stabilised in the last 8 years by valproic acid, who presented in January 2010 an acute drug-induced pancreatitis. Drug-induced pancreatitis has been described since 1955. It may be induced by more than 260 various molecules, as well as by valproic acid, which remains underreported in the literature because there is a problem of imputability.

The prevalence of acute drug-induced pancreatitis is set between 1 and 2 %. However, it must remain as an exclusion diagnosis after conducting an exhaustive etiological investigation that will, notably, eliminate bilary and alcoholic causes. The most incriminated drugs are the inhibitors of the conversion enzyme, sulfa drugs, non-steroidal anti-inflammatory, diuretics and anticonvulsants, including valproic acid. In Tunisia, the prescription of valproic acid is increasing in bipolar disorder therapy because it is known for its weak toxicity and easy handling.

The case of our patient, who suffers from an acute Balthazar stage C pancreatitis with severe evolution after the drug was stopped, the imputability of valproic acid was considered strong and the collegial decision between the surgery, pharmacovigilance and psychiatry services maintained the drug-induced origin and consequently stopped the valproic acid.

This case supports the idea that acute pancreatitis may be induced by valproic acid, even after a prescription lasting for a long period of time, it has no predictable factors and is totally independent of the drug-related dose and of depakine blood levels. There are no predictive factors to the present day, but the evolution is generally good except in rare cases where it may be dangerous. This leads us to think of bipolar patients who are found within weak grounds, such as alcoholics, cancer and HIV positive patients.