GlaxoSmithKline’s anti-seizure drug Potiga (ezogabine) now carries a black-box warning in the United States. The Food and Drug Administration (FDA) has issued a warning that the drug can cause pigment changes, eye abnormalities, and blue skin discoloration. The risks were flagged by the FDA in April. Potiga is used as an adjunct treatment in patients 18 years or older with partial-onset epilepsy. It was approved by the FDA in 2011.
The warning is the most serious type the
FDA issues.
It is not known at this time whether
these side effects are reversible. The FDA said it is working with the pharmaceutical
company to gather and evaluate all available information to better understand
these developments and will update the public when more information is
available.
In the reported cases, the skin
discoloration is described as blue pigmentation, predominantly on or around the
lips or in the nail beds of the fingers or toes. However, more widespread
involvement of the face and legs has also been reported. Scleral and
conjunctival discoloration, on the white of the eye and inside eyelids, has
been observed as well.
The skin discoloration generally
occurred after 4 years of treatment with ezogabine but has appeared sooner in
some patients. In certain cases, retinal abnormalities have been observed in
the absence of skin discoloration.
Another complication for those who
develop these side effects is that they should not stop taking the drug without
first conferring with their prescribing doctor. A sudden cessation of such
treatment can cause serious and life-threatening medical problems, such as
recurrence of seizures.
The
FDA recommends that all patients taking the drug have a baseline eye examination
and periodic eye examinations that should include visual acuity testing and
dilated fundus photography. Periodic examinations may include fluorescein
angiography, ocular coherence tomography, perimetry, and electroretinography.
For patients who are about to start taking Potiga, it is recommended that they
have eye exams before treatment and thereafter every six months.
For a link to the
official FDA warning, click on the link below:
