Vision Risks Prompt FDA to Report Revise of Anti-seizure Drug Potigas LabelNov 1, 2013
The U.S. Food and Drug Administration (FDA) has announced changes to the labeling of the anti-seizure medication Potiga (ezogabine) to underscore previously reported risks for retinal abnormalities, potential vision loss, and skin discoloration, all of which may become permanent, it has recently been learned.
"The revised label includes a new boxed warning, the most serious type of warning FDA gives," because of this risk for retinal abnormalities, notes a statement from the FDA, according to Medscape.com. "We advise that Potiga use be limited to patients who have not responded adequately to several alternative therapies to decrease the frequency of seizures, or epilepsy, and for whom the benefits of treatment outweigh the risks." The agency first described the risks in a Drug Safety Communication in April.
The agency further recommends that every patient have an eye examination by an ophthalmic professional before starting ezogabine, and an exam every six months during treatment. "Patients whose vision cannot be monitored should generally not take Potiga," the FDA statement advises. Medscape reports that it is not clear which patients are at risk for these retinal changes, how long it may take for changes to be detected, how quickly changes can progress, or their reversibility after Potiga use ends.
If retinal pigment abnormalities or vision changes occur, Potiga should be stopped unless no other suitable treatment options are available and the benefits of treatment outweigh the potential risk of vision loss, the FDA recommends.
The revised Potiga label now includes warnings about the risk for discoloration of the skin, nails, mucous membrane, and white of the eye. These risks were also outlined in the April statement, Medscape reports. The label recommends that a new treatment be considered for patients who develop discolorations.
These recommendations have all been added to the Warnings and Precautions section of the label and to the patient Medication Guide included with each prescription, according to Medscape. The updated drug label and the patient Medication Guide are posted on the FDA site, as is the full FDA announcement of the changes.