Potiga Eye, Skin Problems Result in FDA Black Box Warning

The FDA is requiring a new black box warning about the potential side effects of Potiga, an antiseizure drug that may damage the eyes and cause skin problems.  

On October 31, the FDA announced that it is requiring GlaxoSmithKline, the manufacturer of the medication, to place a black box warning on Potiga, which is the strongest warning that can be placed on a prescription medication.

The warning will be placed prominently on the label in a black box, alerting users to the risk of retina abnormalities that can lead to blindness. The label will also highlight a risk of skin discoloration reported among users of Potiga.

The agency is recommending that doctors prescribe Potiga only after patients have failed to respond adequately to several alternative therapies for reducing seizures or treating epilepsy, and then only if the benefits appear to outweigh the risks. If doctors do feel the need to prescribe Potiga, the FDA recommends that patients have eye exams by an ophthalmic professional before starting the drug and every six months during treatment.

The FDA first warned about the risk of health problems from Potiga in an April drug safety communication, which was issued after the agency had received several reports of blue skin discoloration on the lips, nail beds, fingers and toes. There were also reports of changes in the color of the retinas of some users. In certain instances, changes in pigment around the eyes has resulted in eye disease or loss of vision.

FDA officials say they do not know which patients are more likely to be affected, how long it takes for signs of abnormality to be detected, how fast the problem progresses, or if it is reversible after the patient stops taking Potiga. The agency warns that if a patient’s vision cannot be regularly monitored, they should not be prescribed the drug.

If pigment or vision changes are detected, the FDA recommends that patients be taken off Potiga, unless there is no other suitable seizure treatment available. Use of Potiga should also be stopped if it appears patients are not improving.

Potiga, manufactured by Valeant Pharmaceuticals in partnership with GlaxoSmithKline (GSK), is an adjunctive anti-seizure medication that was approved in June 2011 for the treatment of partial-onset seizures in adults 18 years of age and older with epilepsy. Potiga is also sold by its generic name, ezogabine. Because of the risk of other serious side effects, Potiga is distributed under an FDA-required Risk Evaluation and Mitigation Strategy (REMS). FDA officials say they are looking to modify the current Potiga REMS to take the discoloration and vision loss risks into consideration.