Stavzor Liver Failure Risk Results in FDA Black Box Warning

Federal drug regulators indicate that side effects of Stavzor may pose a risk of serious and potentially life-threatening liver problems, resulting in a new “black box” warning being placed on the epilepsy drug.

According to safety information posted by the FDA on April 11, the agency approved label changes for Stavzor (valproic acid) last month, warning about cases of liver failure that have resulted in fatalities for some patients. The statement indicates that the problem affects all drugs that use valproic acid, including Depakote, which already carries a similar warning.  

The Stavzor liver problems have usually occurred during the first six months of treatment, according to the warning, and may be preceded by non-specific symptoms like malaise, weakness, lethargy, facial edema, anorexia and vomiting.

The label warns that children under the age of two may be at considerably increased risk of developing liver toxicity. Others at high risk include patients with congenital metabolic disorders, severe seizure disorders accompanied by retardation, and patients with Mitochondrial Disease.

Stavzor is one of several anti-seizure drugs that contain valproic acid, which has also been linked to a risk of severe birth defects and malformations when used during pregnancy. Use of Depakote and other valproic acid medications have been linked to cases of spina bifida, cleft palate, abnormal skull development, malformed limbs, holes in the heart and urinary tract problems, especially when the drugs are taken during the first 28 days of pregnancy.

In 2006, the FDA added a “black box” warning about the potential risk of Depakote birth defects after a study found that 20% of pregnant mothers who gave birth while on Depakote had a child with malformations or a birth defect.

In May 2013, the FDA put new restrictions on Depakote pregnancy use, contraindicating it for pregnant women, but only when it was used for the treatment of migraines. The agency did not contraindicate it for pregnant women. The FDA changed all valproate-based drugs from a class “D” to a class “X” pregnancy drug, but only as they pertain to migraines.

Abbott Laboratories currently faces a number of Depakote birth defect lawsuits filed by families throughout the country, which allege that the drug maker failed to adequately research the medication or warn consumers and the medical community about the risks associated with using the popular medication during pregnancy.