FDA Warning: Drug Used by 2 Million Americans Has Fatal Side Effect

The FDA issued a notice that an anti-seizure medication could trigger deadly side effects.

Signage is seen outside of the Food and Drug Administration (FDA) headquarters in White Oak, Maryland, U.S., August 29, 2020. REUTERS/Andrew Kelly

The U.S. Food and Drug Administration (FDA) warned in a recent notice that two anti-seizure medications used by more than 2 million Americans could trigger life-threatening side effects.

Levetiracetam and clobazam were both linked to a condition known as Drug Reaction with Eosinophilia and Systemic Symptoms, or DRESS, said the FDA last week in a notice on its website.

The federal health agency said the the two drugs can “cause a rare but serious reaction that can be life-threatening if not diagnosed and treated quickly,” adding that manufacturers of the drugs are being mandated to add new warnings about the condition.

“It may start as a rash but can quickly progress, resulting in injury to internal organs, the need for hospitalization, and even death,” the FDA notice said. “This hypersensitivity reaction to these medicines is serious but rare. DRESS can include fever, rash, swollen lymph nodes, or injury to organs including the liver, kidneys, lungs, heart, or pancreas,” it added.

The agency said that it doesn’t want people to stop using the medication.

In 2020, approximately 1.4 million Americans used levetiracetam, which is sold under the brand names Keppra, Keppra XR, Elepsia XR, and Spritam, according to a medication database. It was first approved by the FDA more than two decades ago, while more than 12 million prescriptions were handed out in 2022, the FDA said.

Clobozam, a benzodiazepine sold under the names Onfi and Sympazan, is indicated for use in combination with other medicines to deal with seizures and adults who have a specific form of epilepsy known as Lennox-Gastaut syndrome. Around 779,000 clobazam prescriptions were dispensed across the United States in 2022, according to the agency.

The federal agency’s Adverse Event Reporting System, known as FAERS, shows that as of March 2023, about 32 serious DRESS cases were reported worldwide that have been associated with levetiracetam, reported Medscape. In all 32 cases, the patients were hospitalized and two people died.

The FAERS database shows that up until July of this year, 10 serious cases of DRESS have been reported worldwide. All 10 patients were hospitalized and none died, the outlet reported.

“Health care professionals should be aware that prompt recognition and early treatment is important for improving DRESS outcomes and decreasing mortality,” the FDA notice stated.

The condition can be difficult to diagnose, the FDA said, because certain symptoms such as a fever and swollen lymph nodes might appear without a rash. The reaction “typically occurs 2 weeks to 8 weeks after starting these medicines,” the agency said.

Patients shouldn’t stop taking levetiracetam or clobazam without speaking with a health care professional or doctor, it added. Stopping taking the drugs may suddenly trigger seizures, the FDA said.

“All medicines have side effects even when used correctly as prescribed. It is important to know that people respond differently to all medicines depending on their health, the diseases they have, genetic factors, other medicines they are taking, and many other factors,” the FDA notice says. “As a result, we cannot determine how likely it is that someone will experience DRESS, a rare but serious reaction, when taking levetiracetam or clobazam. Your health care professional knows you best, so talk to them if you have questions or concerns about the risks of taking these medicines.”