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RETINAL ABNORMALITIES AND POTENTIAL VISION LOSS
- POTIGA can cause retinal abnormalities with funduscopic features similar to those seen in retinal pigment dystrophies, which are known to result in damage to the photoreceptors and vision loss.
- Some patients with retinal abnormalities have been found to have abnormal visual acuity. It is not possible to determine whether POTIGA caused this decreased visual acuity, as baseline assessments are not available for these patients.
- Approximately one third of the patients who had eye examinations performed after approximately 4 years of treatment were found to have retinal pigmentary abnormalities. An earlier onset cannot be ruled out, and it is possible that retinal abnormalities were present earlier in the course of exposure to POTIGA. The rate of progression of retinal abnormalities and their reversibility are unknown.
- POTIGA should only be used in patients who have responded inadequately to several alternative treatments and for whom the benefits outweigh the potential risk of vision loss. Patients who fail to show substantial clinical benefit after adequate titration should be discontinued from POTIGA.
- All patients taking POTIGA should have baseline and periodic (every 6 months) systematic visual monitoring by an ophthalmic professional. Testing should include visual acuity and dilated fundus photography. Additional testing may include fluorescein angiograms (FA), ocular coherence tomography (OCT), perimetry, and electroretinograms (ERG).
- If retinal pigmentary abnormalities or vision changes are detected, POTIGA should be discontinued unless no other suitable treatment options are available and the benefits of treatment outweigh the potential risk of vision loss.
The chemical name of ezogabine is N-[2-amino-4-(4-fluorobenzylamino)-phenyl] carbamic acid ethyl ester, and it has the following structure:
The empirical formula is C16H18FN3O2, representing a molecular weight of 303.3. Ezogabine is a white to slightly colored, odorless, tasteless, crystalline powder. At room temperature, ezogabine is practically insoluble in aqueous media at pH values above 4, while the solubility is higher in polar organic solvents. At gastric pH, ezogabine is sparingly soluble in water (about 16 g/L). The pKa is approximately 3.7 (basic).
POTIGA is supplied for oral administration as 50-mg, 200-mg, 300-mg, and 400-mg film-coated immediate-release tablets. Each tablet contains the labeled amount of ezogabine and the following inactive ingredients: carmine (50-mg and 400-mg tablets), croscarmellose sodium, FD&C Blue No. 2 (50-mg, 300-mg, and 400-mg tablets), hypromellose, iron oxide yellow (200-mg and 300-mg tablets), lecithin, magnesium stearate, microcrystalline cellulose, polyvinyl alcohol, talc, titanium dioxide, and xanthan gum.
What are the possible side effects of ezogabine (Potiga)?
Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Report any new or worsening symptoms to your doctor, such as: mood or behavior changes, depression, anxiety, panic attacks, or if you feel agitated, hostile, aggressive, restless, hyperactive (mentally or physically), or have thoughts about suicide or hurting yourself.
Call your doctor at once if you have a serious side effect such as:
- painful or difficult urination;
- urinating less than usual or not...
Last reviewed on RxList: 9/19/2013
This monograph has been modified to include the generic and brand name in many instances.
Additional Potiga Information
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
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