Certain patients may be at risk of developing hemophagocytic lymphohistiocytosis, also known as HLH. The new warning for Lamictal, required by the Food and Drug Administration, will warn prospective patients about the problems of serious immune system reactions to the drug.

According to the FDA, the new warning for Lamictal is a result of problems that may affect patients who are taking this drug for treatment of bipolar disorder or seizures. The agency says that the medication may lead to a very serious reaction that activates the infection-fighting immune system within the patient, causing critical inflammation throughout the body.

Before the research and news of the warning to be placed on the drug’s label, some patients say that they had to suffer the risk of this side effect without knowledge about how much it could harm them.

The immune system reaction, referred to as hemophagocytic lymphohistocytosis, or HLH, is an uncontrolled response within the body. It usually presents as an extremely high fever and can cause problems with the body’s organs and blood cells, such as the lungs, kidneys and the liver.

Some patients say they developed sudden pain and medical conditions that weren’t otherwise explained, and they say that the company making the drug should have told users about the dangers before it became such a widespread problem. Most drugmakers carry out testing before and after a drug goes to market in order to minimize the chances of painful side effects or the development of other medical conditions.

Before the new warning for Lamictal, patients suffered severe side effects that resulted in hospitalization and even fatalities without knowing about the risk. The new warning for Lamictal is designed to advise patients about this risk prior to taking the medication.

The new warning for Lamictal informs patients about the risk of HLH. Patients should be on the look out for five of the following signs of HLH, including high levels of blood ferritin, cytopenia, enlarged spleen, fever and rash, elevated triglyceride levels, absent or decreased natural killer NK cell activity, elevated blood levels of CT-25, indicating immune cell activation, and hemophagocytosis identified through the spleen, lymph node or bone marrow biopsy.

Some of the symptoms shared on the new warning for Lamictal include unusual bleeding, skin rashes, swollen lymph nodes and enlarged liver, fever and nervous system problems. Those patients who have already been affected by serious side effects may be able to pursue a lawsuit against the manufacturers if they can show that they were not properly warned about the risks and that the maker of the medication knew about it or should have known about it in advance.