The U.S. Food and Drug Administration warned that GlaxoSmithKline Plc’s antiepileptic drug Lamictal (lamotrigine) can cause a brain and spinal cord inflammation known as aseptic meningitis.

Between December 1994 and November 2009, 40 cases of serious complication not involving meningitis-causing bacteria were cited by the FDA.

The FDA said symptoms of meningitis including headache, fever, drowsiness, confusion, myalgias, and photophobia appeared between one and 42 days after initiating lamotrigine therapy. The symptoms resolved after the drug was discontinued, but returned in 15 patients when they restarted the drug, the agency said.

Cerebrospinal fluid collected from 25 patients showed normal glucose levels, moderate pleocytosis and a moderate increase in protein, the FDA indicated. Some patients developed abnormalities in the liver and kidneys possibly because of hypersensitivity or a drug reaction.

The National Institutes of Health say aseptic meningitis is not as serious as the life-threatening bacterial meningitis, and patients tend to recover within five to 14 days.

The FDA said it is working on adding a warning information on the meningitis risk to the drug’s label and patient medication guide.

"Aseptic meningitis is a rare but serious side effect of Lamictal use," said Russell Katz, head of the FDA division that oversees neurology products. "Patients that experience symptoms should consult their health care professional immediately."