Horizant (gabapentin enacarbil)

Company
GlaxoSmithKline

Approval Status
Approved April 2011

Treatment for
restless legs syndrome

Possible similar drugs
Horizant

Areas
Neurology & Nervous System

Horizant is an extended-release formulation of gabapentin enacarbil, a prodrug of gabapentin. The precise mechanism by which gabapentin is efficacious in RLS is unknown. Gabapentin is structurally related to the neurotransmitter gamma-aminobutyric acid (GABA) but has no effect on GABA binding, uptake, or degradation.

Horizant is specifically indicated for the treatment of moderate-to-severe primary Restless Legs Syndrome (RLS) in adults.

Horizant is supplied as an extended release tablet for oral administration. The recommended dosage is 600 mg once daily taken with food at about 5 PM.

FDA Approval
The FDA approval of Horizant was based on two 12-week clinical studies in approximately 400 adults with RLS. The subjects were required to have a total score of ≥15 on the International Restless Legs Syndrome (IRLS) Rating Scale at baseline. In Study 1 the subjects received the 1,200mg of Horizant or placebo taken once daily at about 5 PM with food. In Study 2 the subjects received 600 mg of Horizant, 1,200 mg of Horizant or placebo taken once daily at about 5 PM with food. Efficacy was evaluated using the IRLS Rating Scale and Clinical Global Impression of Improvement (CGI-I) score. Statistically significant differences (P<0.05) between the treatment groups receiving 600 and 1,200 mg of Horizant and the group receiving placebo were observed at Week 12 for both the mean change from baseline in the IRLS Scale total score and the proportion of responders (much improved) or (very much improved) on the CGI-I Scale.

Adverse events associated with the use of Horizant may include, but are not limited to, the following:

  • somnolence/sedation
  • dizziness
  • headache

Horizant is an extended-release formulation of gabapentin enacarbil, a prodrug of gabapentin. The precise mechanism by which gabapentin is efficacious in RLS is unknown. Gabapentin is structurally related to the neurotransmitter gamma-aminobutyric acid (GABA) but has no effect on GABA binding, uptake, or degradation.

For additional information regarding Horizant or restless legs syndrome, please visit the Horizant web page.

Horizant_1142 Drug Information

The Horizant_1142 drug information shown above is licensed from Thomson CenterWatch. The information provided here is for general educational purposes only and does not constitute medical or pharmaceutical advice which should be sought from qualified medical and pharmaceutical advisers.

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