Side Effects of Dilantin, Tegretol, Other Epilepsy Drugs Linked to Fracture Risk

Epilepsy drugs like Dilantin and Tegretol may be linked to an increased risk of fractures in older patients, according to the findings of a new study. 

Researchers from Canada found a correlation between the use of epilepsy drugs and an increased risk of fracture in every major antiepileptic except Depakote and other valproic acid-based drugs. Dilantin was found to carry the highest risk of fractures. Their findings were published in this month’s issue of the Archives of Neurology.

The researchers conducted a cohort study of 15,792 people age 50 and older who suffered nontraumatic wrist, hip and vertebra fractures between 1996 and 2004. They found that the risk of fracture increased between about 24% for clonazepam-based drugs, like Klonopin and Valpax, and 91% for Dilantin. They found no increased risk in those taking Depakote.

Much of the recent attention on antiepileptic drugs by scientists has focused on suicide risks and birth defects. In 2008, the FDA conducted a  meta-analysis that led to a 2008 decision requiring all epilepsy drugs to carry a suicide risk warning. But some researchers have said that risk appears to be limited to newer epilepsy drugs while older drugs, like Depakote, Neurontin and Lamictal, appeared to have no increased risk of suicide.

Dilantin (phenytoin) is an antiepileptic drug manufactured by Pfizer. Mylan makes a generic version called Phenytek which is considered bioequivalent.

In November 2008, the FDA issued a warning about a risk of Stevens-Johnson syndrome from Dilantin and its generic equivalents. It has also been linked to a rare condition known as Purple Glove Syndrome.

Stevens-Johnson Syndrome (SJS) is a painful and debilitating reaction that has been linked to several medications. It can cause the skin to burn, producing blisters, severe rashes and the skin may begin to separate from the body. When the skin lesions affect more than 30% of the body, the condition is typically referred to as toxic epidermal necrolysis (TEN). Treatment in a hospital Intensive Care Unit (ICU) or Burn Unit is often required, and the conditions can be fatal in many cases.