Vigafyde (vigabatrin oral solution)

Short answer: Vigafyde is vigabatrin as a ready-to-use oral solution, 100 mg per mL, approved by the FDA on 17 June 2024.¹ It is labeled only for infantile spasms in babies 1 month to 2 years old. The dose is drawn straight from the bottle, with no mixing, and it can also go through a gastrostomy (G) tube.² It is the same medicine as Sabril and the generic powders, with the same boxed warning about permanent vision loss.²

In FDA records, Vigafyde is the only ready-to-use vigabatrin solution; every generic vigabatrin is a powder or a tablet.³

What is Vigafyde?

Vigafyde is a clear, peppermint-flavored liquid sweetened with sucralose. It comes in a 150 mL bottle.² The pharmacy provides an oral syringe and a bottle adapter.² The FDA application (NDA 217684) is held by Pyros.¹ The current label lists Upsher-Smith as the distributor.²

Its approval rests on how its composition compares with vigabatrin powder solution, not on new efficacy trials. Its benefits and risks are therefore those of vigabatrin itself.² The evidence for vigabatrin in infantile spasms therefore applies to Vigafyde too.

Who is Vigafyde for?

The label covers one use: monotherapy for infantile spasms in babies 1 month to 2 years old "for whom the potential benefits outweigh the potential risk of vision loss." It is not approved for refractory complex partial seizures or for adults.² Older children and adults use tablets or powder sachets instead.

How Vigafyde differs from vigabatrin powder

From the FDA labels.^2,4

The label says Vigafyde "does not require additional reconstitution or dilution." With a GJ tube, the dose goes through the G-port, and the tube is flushed with water afterward.² Tablets are included in the full comparison of liquid, powder and tablets.

Vigafyde dosing

Dosing is by weight. The label starts at 50 mg/kg a day, split into two doses, and raises it by 25 to 50 mg/kg a day every 3 days as needed, up to 150 mg/kg a day.²

From the Vigafyde label dosing table.²

Use a calibrated oral syringe, not a kitchen spoon.² Small volumes are harder to measure, so ask for a syringe sized to your baby's dose.^5,6 Tips for each step are in how to give liquid medicine to a baby. The dose calculator shows label volumes for each weight.

Ready-to-use liquid, 100 mg/mL

7.5 mL

Drawn straight from the bottle. Fits in one 10 mL oral syringe.

Mixed powder, 50 mg/mL

15 mL

Two packets dissolved in 20 mL of water; 15 mL is given and 5 mL is thrown away. More than one 10 mL syringe-full.

Scale marks every 1 mL, 0–20 mL. Volumes from the FDA dosing tables for each product. Twice daily.

Switching to Vigafyde from powder

This is the step where errors can happen. Vigafyde is twice as concentrated as mixed powder, so the same dose is half the number of mL. The label warns prescribers, pharmacists and caregivers to check the volume when switching.² Its instructions for use tell parents who used powder before that the prescriber "may have prescribed a smaller volume (mL) of medicine than before."²

For a 10 kg baby at the maximum dose, that is 7.5 mL of Vigafyde instead of 15 mL of mixed powder.^2,4 Giving the old number of mL of the new liquid would double the dose. Ask for the new volume in writing, and mark it on the syringe.

Dose accuracy: what the evidence shows

One study has compared the two forms directly. Thirty people, 15 experienced vigabatrin caregivers and 15 first-time users, each prepared one 1,125 mg dose from a ready-to-use solution and one from Sabril powder, using only the written instructions.⁷

• Ready-to-use liquid
• Mixed powder

Within 10% of the target dose

Ready-to-use liquid

100%

Mixed powder

77%

Within 2% of the target dose

Ready-to-use liquid

70%

Mixed powder

20%

30 people, one 1,125 mg dose of each. Small study funded by the liquid’s maker.

Show as a table

Group	Measure	Value
Within 10% of the target dose	Ready-to-use liquid	100%
Within 10% of the target dose	Mixed powder	77%
Within 2% of the target dose	Ready-to-use liquid	70%
Within 2% of the target dose	Mixed powder	20%

All 30 liquid doses were within 5% of the target. Only 23 of 30 powder doses were within 10%, and powder doses ranged from 62% too little to 24% too much. Measuring the volume was equally accurate for both, so the authors put the errors down to mixing.⁷

Limits of this study. The authors worked for Pyros, which holds Vigafyde's FDA application. It was small, and each person made a single dose in a test setting. The liquid arm used a stand-in solution made to match Vigafyde, and its doses were calculated from the volume rather than measured in the lab. The target dose was larger than most infant doses. No study has compared seizure outcomes between the forms.⁷

Why it may still matter: babies who respond to vigabatrin usually do so within days, a median of 3 days in one 23-center US study.⁸ Doses that come out short in that window are a real concern, though no study has linked the choice of form to a baby's outcome.

Vigafyde side effects

Vigafyde has the side effects of vigabatrin. In a placebo-controlled study in infantile spasms, these were more common on vigabatrin: sleepiness (45% vs 30% on placebo), bronchitis (30% vs 15%), ear infection (10% vs 5%) and acute middle-ear infection (10% vs 0%).²

• Brain MRI changes. These were seen in 22% of babies on vigabatrin vs 4% on other treatments.²
• Weight gain. In pooled pediatric trials, 47% gained 7% or more of their body weight, vs 19% on placebo.²
• Vision loss. Vision loss can be permanent. The label asks for vision checks at baseline (no later than 4 weeks after starting), at least every 3 months on treatment, and about 3 to 6 months after stopping.²
• Stopping. Avoid stopping abruptly; the dose is tapered.²

Vigafyde reviews: what parents report

We found no published study of parents' experience with Vigafyde, such as taste, ease of use or satisfaction. The only published study involving the product is the dose-accuracy study above, and it did not ask about babies taking the medicine. Online star ratings are not research, and we do not repeat them here. If you want to hear from other families, ask your baby's neurology team or a patient group.

How to get Vigafyde

Like every vigabatrin product, Vigafyde is available only through the Vigabatrin REMS. The prescriber must be certified, the baby enrolled and the pharmacy certified.² The program's site is vigabatrinREMS.com and its phone line is 1-866-244-8175.²

1. Ask the prescriber whether Vigafyde suits your baby. It is labeled only for infantile spasms from 1 month to 2 years.
2. The prescriber completes the REMS enrollment with you and sends the prescription.
3. A certified pharmacy fills the prescription. Upsher-Smith's support program lists home delivery and pharmacist help at any hour.⁹

Upsher-Smith, Vigafyde's distributor, runs the Promise of Support program. It lists help with prior authorizations and appeals, and a Quick Start program so a baby can begin treatment while insurance approval is in progress. It notes that restrictions apply.⁹ This site is independent and does not run or endorse any program.

Vigafyde cost, coupons and coverage

We do not publish prices, because they change and what each family pays differs. What you pay depends on your plan's coverage of Vigafyde, any prior authorization, and the pharmacy. Ask your plan whether it prefers another product. If the prescriber chose the liquid for a reason, ask the office whether it can request an exception.

Copay help. Upsher-Smith's Promise of Support page lists copay help for eligible patients and a patient assistance program for the uninsured or underinsured. Restrictions apply.⁹ Ask whether the program applies to your type of insurance. The Vigafyde caregiver site also lists 1-888-650-3789 (general contact number).⁹

How long a bottle lasts. One 150 mL bottle holds 15,000 mg. At a 5 kg baby's starting dose it lasts 60 days; at a 10 kg baby's maximum dose, 10 days. An opened bottle is discarded 90 days after opening.² Because doses change with weight, ask the pharmacy to re-check quantity limits when the dose changes.

Vigafyde, Sabril and Vigadrone

All three contain vigabatrin. Sabril is the original brand of tablets and powder, and Vigadrone is a generic powder and tablet. Vigafyde is the only one sold as a ready-to-use liquid, and the only one labeled just for infantile spasms.^2,3 The other first options are compared in the infantile spasms treatment guide.