Vigabatrin, Sabril (US/CDN)/Vigadrone (US)
Description: Anticonvulsant, Miscellaneous
“ALERT: US Boxed Warning
Permanent vision loss:
Vigabatrin can cause permanent bilateral concentric visual field constriction, including tunnel vision that can result in disability. In some cases, vigabatrin also can damage the central retina and may decrease visual acuity.
The onset of vision loss from vigabatrin is unpredictable and can occur within weeks of starting a treatment or sooner, or at any time after starting treatment, even after months or years.
Symptoms of vision loss from vigabatrin are unlikely to be recognized by the patients or caregivers before vision loss is severe. Vision loss of milder severity, while often unrecognized by the patient or caregiver, can still adversely affect function.
The risk of vision loss increases with increasing dose and cumulative exposure, but there is no dose or exposure known to be free of risk of vision loss.
Vision assessment is recommended at baseline (no later than 4 weeks after starting vigabatrin), at least every 3 months during therapy, and about 3 to 6 months after the discontinuation of therapy. Once detected, vision loss caused by vigabatrin is not reversible. It is expected that, even with frequent monitoring, some patients will develop severe vision loss.
Consider drug discontinuation, balancing benefit, and risk, if vision loss is documented.
The risk of new or worsening vision loss continues as long as vigabatrin is used. It is possible that vision loss can worsen despite discontinuation of vigabatrin.
Because of the risk of vision loss, vigabatrin should be withdrawn from patients with refractory complex partial seizures who fail to show substantial clinical benefit within 3 months of initiation and within 2 to 4 weeks of initiation for patients with infantile spasms, or sooner if treatment failure becomes obvious. Patient response to and continued need for vigabatrin should be periodically reassessed.
Vigabatrin should not be used in patients with, or at high risk of, other types of irreversible vision loss unless the benefits of treatment clearly outweigh the risks.
Vigabatrin should not be used with other drugs associated with serious adverse ophthalmic effects such as retinopathy or glaucoma unless the benefits clearly outweigh the risks.
Use the lowest dosage and shortest exposure to vigabatrin that is consistent with clinical objectives.
Because of the risk of permanent vision loss, vigabatrin is available only through a restricted program under a risk evaluation and mitigation strategy (REMS) called the Vigabatrin REMS program. Further information is available at http://www.vigabatrinREMS.com or by calling 1-866-244-8175.”
CSA NA – FDA Approved – REMS (Y) – Cannot Ship
How Does It Work
Vigabatrin, Sabril/Vigadrone irreversibly inhibits gamma-aminobutyric acid transaminase (GABA-T), increasing the levels of the inhibitory compound gamma amino butyric acid (GABA) within the brain. Duration of effect is dependent upon the rate of GABA-T resynthesis.
Indications For Use
Refractory complex partial seizures; Infantile spasms
Before starting Vigabatrin, Sabril/Vigadrone make sure your physician is aware of any allergies or medications you currently take, if you have a history of psychosis, renal impairment, a seizure disorder, are pregnant, or breastfeeding. Vigabatrin, Sabril/Vigadrone use has been associated with rare but serious adverse events such as anemia, CNS depression, edema, neurotoxicity, peripheral neuropathy, suicidal ideation, vision loss, and weight gain.
Oral: 500 mg twice daily; increase the daily dose by 500 mg increments at weekly intervals based on response and tolerability. Recommended dose: 1.5 g twice daily.
Pharmacist Tips On Using
How to Take: Administer without regard to meals.
You Need to Avoid: Anticonvulsants should not be discontinued abruptly because of the possibility of increasing seizure frequency; therapy should be withdrawn gradually to minimize the potential of increased seizure frequency unless safety concerns require a more rapid withdrawal.
Skin rash, weight gain, constipation, diarrhea, vomiting, viral infections, dizziness, drowsiness, fatigue, headache, insomnia, irritability, sedation, tremor, blurred vision, nystagmus disorder, visual field loss, otic infection, otitis media, fever, bronchitis, nasal congestion, nasopharyngitis, pneumonia, upper respiratory tract infection
Note this is not a complete list
Frequently Asked Questions
What do I do if side effects are intolerable?
If side effects are causing a lot of distress speak to your physician as soon as possible to discuss options.