FDA Publishes Drug Safety Communication for Antiseizure Drugs

Earlier this week, the United States Food and Drug Administration (FDA) published a drug safety communication warning patients about potentially life-threatening side effects linked to levetiracetam and clobazam. Levetiracetam — sold under the brand names Keppra, Keppra XR, Elepsia XR, or Spritam — and clobazam, sold as Onfi or Sympazan, are FDA-approved antiseizure medications.

According to the press release, levetiracetam has been FDA-approved for nearly 2.5 decades to manage seizures alone or in combination with other drugs, depending on the type of seizure. Meanwhile, clobazam is a benzodiazepine that is used alongside other medications to control seizures from Lennox–Gastaut Syndrome, a type of epilepsy.

The administration notes that, in some cases, patients taking these drugs will experience rare but potentially life-threatening reactions called Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS). The condition may begin as a rash but can quickly develop into a fever, swollen lymph nodes, and damage to internal organs, including the liver, kidneys, lungs, heart, or pancreas.

The administration notes that a cumulative review of the drugs identified 42 global cases of DRESS for patients taking these antiseizure drugs. However, the actual number may be higher, as the review only included events reported to the FDA or published in studies. Approximately 32 cases were linked to levetiracetam, while the remaining 10 were associated with clobazam based on the onset of DRESS after treatment.

Based on the data collected, the FDA is taking steps to update the safety information on these drugs.

The prescribing information and medication guide for patients and caregivers will be updated with new warnings and precautions. Additionally, the labels will include information on the early warning signs of DRESS to provide users with the tools to recognize the effects early on.

However, the FDA notes patients should not discontinue the medications without talking to their healthcare provider.

“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. 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,” explained the administration in its safety communication.

Beyond regulatory-level actions, the FDA is advising that any patients taking these drugs who begin exhibiting unusual symptoms or reactions see immediate medical attention in an emergency department.

Healthcare providers prescribing medications should inform their patients of the potential risks and be mindful of symptoms. Both providers and patients can report adverse events to the FDA MedWatch program.