Jan 22 (Reuters) - The U.S. Food and Drug Administration

on Wednesday warned about the risk of a rare but serious

allergic reaction with the use of some multiple sclerosis drugs

including Teva's Copaxone.

The health regulator is adding a new boxed warning, the

FDA's most prominent warning, to include information that a

serious allergic reaction called anaphylaxis can occur at any

time, from as early as after the first dose or following doses

administered years after starting the medicine.

The drug, glatiramer acetate, is approved to treat patients

with relapsing forms of multiple sclerosis, a chronic disease

that affects the central nervous system.

Teva markets the drug under the name Copaxone, while a

generic version of the drug, Glatopa, is sold by Sandoz.

The companies did not immediately respond to requests for

comment.

Most patients who experienced anaphylaxis following the use

of the drug saw symptoms appear within one hour of the drug

being administered via injection, the FDA said, adding that in

some cases, the allergic reaction resulted in hospitalization

and death.

The health regulator identified 82 worldwide cases of

anaphylaxis associated with the use of the drug from December

1996 through May 2024, including 19 cases that reported

anaphylaxis more than a year after starting the medicine.

The patients needed emergency room visits or

hospitalizations for medical treatment, and six died, according

to the FDA.

The symptoms such as wheezing or difficulty in breathing,

swelling of the face, lips, or throat, and hives, can quickly

progress to more serious symptoms, including severe rash or

shock, which is a life-threatening condition.

Those experiencing a reaction after the medicine is

administered should seek immediate medical attention if the

symptoms are more than mild, get worse over time, or do not go

away within a brief time, the FDA said.