FDA issues warning over fatal skin reactions with anti-seizure drug Onfi (clobazam)

by Charles Miller

The Food and Drug Administration has issued a warning about the risk of serious and potentially fatal skin reactions among patients who use the anti-seizure drug Onfi (clobazam). According to the agency, the use of Onfi may cause patients to develop Stevens-Johnson Syndrome (SJS) or toxic epidermal necrolysis (TEN), two skin conditions which can lead to hospitalization, blindness, or death.

Onfi is an anti-epilepsy medication that is used to treat patients who experience seizures caused by a condition known as Lennox-Gastaut Syndrome (LGS). The drug is part of a class of anti-seizure drugs known as benzodiazepines. So far, Onfi is the only benzodiazepine associated with fatal skin reactions.

So far, the FDA has received reports of at least 20 patients who developed SJS or TEN after taking Onfi. All 20 of these patients were hospitalized as a result of their condition. One patient was killed and another was blinded as a result of their illness. Five out of the 20 patients were children.

The FDA has advised doctors to closely monitor their patients when starting them on Onfi or resuming treatment with the drug in order to watch for signs of SJS or TEN. Symptoms of these conditions may include:

  • Rashes
  • Blisters
  • Peeling skin
  • Mouth sores
  • Hives

The FDA has advised doctors to stop treatment with Onfi at the first signs of a rash. If other symptoms (such as those listed above) indicate a serious skin reaction, the agency has advised physicians not to resume treating the patients with the drug.

The FDA also advised doctors to inform patients that they should seek medical attention as soon as possible if they notice a rash or other symptoms that may indicate SJS or TEN. Patients should not stop taking Onfi without talking with their doctor, the FDA says, because this could trigger seizures, nervousness, hallucinations or other withdrawal symptoms.

Help For Patients Who Have Been Injured By Dangerous Drugs

If you or a loved one have suffered injuries or illnesses caused by dangerous drugs or other medical products, you may be eligible to file a lawsuit and seek compensation for your injuries. The first step to filing a case is to speak with an experienced attorney who can help you navigate the process of bringing a lawsuit to court.

For a free legal consultation about your case and to find out if you are eligible to file a lawsuit, contact the lawyers at Heygood, Orr & Pearson by calling us toll-free at 1-877-446-9001. You can also reach us by filling out the brief case evaluation form located at the top of this page.


Case results depend upon a variety of factors unique to each case. Results of other cases do not guarantee or predict a similar result in any future case.

Charles Attorney Headshot

by Charles Miller

Charles Miller is a licensed attorney and a partner at Heygood, Orr & Pearson. Charles focuses his practice on areas of complex commercial litigation and personal injury litigation.