Research suggests that taking Gilenya (fingolimod), a drug used to treat multiple sclerosis, can increase the risk of lymphopenia in underweight women. According to EmaxHealth, this increased risk is also observed in individuals who have low lymphocyte levels before beginning treatment.
Lymphopenia, also referred to lymphocytopenia, is a condition that results in a deficiency of lymphocytes. Lymphocytes are a type of white blood cells; they can be T cells, B cells or natural killer cells. Lymphocytes play a vital role in the immune system. According to EmaxHealth, Gilenya has been known to lower the levels of lymphocytes circulating in the body. This side effect has been reported by the U.S. Food and Drug Administration and manufacturer Novartis.
Due to the lowered lymphocyte levels, patients are at a higher risk of infections. Two recently published studies, one in Germany and one in Sweden, analyzed factors associated with this risk. The German study involved 418 individuals with relapsing-remitting multiple sclerosis took 0.5 mg of Gilenya every day. Blood samples were taken from these patients right before treatment, and at 1 month, 4 months and 6 months. The Swedish study analyzed data from 438 patients to confirm the findings.
The findings showed a 26 percent increased risk of lymphopenia in women who had a body mass index (BMI) less than 18.kg/m2, EmaxHealth reports. This was risk was not apparent in men. In patients who had lymphocyte levels less than 1.6 x 109/L, there was a 46 percent increased risk of lymphopenia. Researchers also observed that use of Copaxone prior to using Gilenya seemed to protect against the development of lymphopenia, but the immunologic effects of this drug are unknown. Past research shows that the lowered lymphocyte levels in MS patients taking Gilenya is not influenced by meal timing or use of other medications, such as corticosteroids.
The findings are an additional consideration for doctors who may prescribe Gilenya; the information is especially relevant to women who are underweight and/or have low baseline lymphocyte levels. Other side effects associated with Gilenya include slow heart rate (bradycardia), macular edema, liver problems and shortness of breath.