Anti-Seizure Medication, Dilantin, Tied to Episodes of Stevens Johnson SyndromeSep 12, 2016
Dilantin (phenytoin) is an anti-epilepsy drug sold by Pfizer Inc. and approved by the U.S. Food and Drug Administration (FDA) in 1938 to manage temporal lobe and grand mal seizures. Dilantin affects the brain's sodium channels, suppressing abnormal electrical activity. In addition to its other known adverse reactions, Dilantin has been associated with a serious, sometimes fatal skin reaction known as Stevens Johnson Syndrome (SJS).
SJS often occurs as a severe allergic reaction to a medication and has recently been reported as a Dilantin side effect.
SJS leads to severe blistering and inflammation of the mucous membranes. Patients with SJS sometimes feel as though their skin is being burned from the inside out. When these skin lesions affect more than 30 percent of the body, the disorder is known as Toxic Epidermal Necrolysis (TEN). Not all SJS and TEN sufferers survive, and those who do are often left with permanent injuries, such as vision problems, difficulty eating, and scarring. In some patients, the symptoms of SJS or TEN may return even though the patient stops taking the drug that caused the reactions. Both SJS and TEN are potentially deadly, similar to severe burn cases, and are often treated in the intensive care unit (ICU) or hospital burn unit.
While SJS may cause large areas to blister and peel, leading to open sores and infection, TEN causes large areas of the skin to detach from the body, which may lead to lesions developing in the mucous membranes. Symptoms include:
- Blisters on the skin and the mucous membranes of the mouth, nose, eyes, and genitals
- Facial swelling
- Flu-like symptoms: Fever, sore throat, cough, burning eyes
- Open sores
- Significant skin shedding, sloughing
- Skin pain
- Skin rash, often red or purple, that occurs within hours to days
- Tongue swelling
According to a study published in the Journal of the American Medical Association (JAMA), people who have suffered from an episode of SJS or TEN are significantly more likely to experience a second episode compared to the risk of a first episode in the general population.
In a Dilantin-SJS study published in The Journal of the American Medical Association (JAMA), researchers isolated and identified a CYP2 gene variant that may determine if use of Dilantin causes patients to develop SJS. The research involving cases from 2002 to 2014 involved 105 patients who took Dilantin and developed adverse reactions, including SJS; 130 patients who tolerated Dilantin well; and a control group of 3,655 subjects who were not taking Dilantin. The research proposed potential links concerning the role of genetics in determining a patient's risk for developing SJS, given that patients with specific CYP2C gene variants appeared to be likelier to suffer severe skin reactions when taking Dilantin.
Dilantin has been named approximately 100 lawsuits alleging that Dilantin let to SJS and also alleging that Pfizer was aware of the Dilantin SJS/TEN side effects, but did not inform physicians or potential patients of these risks.