WHA

Horizant (gabapentin enacarbil)

Indications for Prior Authorization

Horizant (gabapentin enacarbil)
  • For diagnosis of Restless Legs Syndrome (RLS)
    Indicated for the treatment of moderate-to-severe primary restless legs syndrome (RLS) in adults. Horizant is not recommended for patients who are required to sleep during the daytime and remain awake at night.

  • For diagnosis of Postherpetic Neuralgia (PHN)
    Indicated for the management of postherpetic neuralgia (PHN) in adults.

Criteria

Horizant

Prior Authorization (Initial Authorization)

Length of Approval: 6 Month(s)
For diagnosis of Restless Legs Syndrome (RLS)

  • Diagnosis of moderate-to-severe primary restless legs syndrome (RLS)
Horizant

Prior Authorization (Reauthorization)

Length of Approval: 12 Month(s)
For diagnosis of Restless Legs Syndrome (RLS)

  • Patient has experienced an improvement in RLS disease symptoms (e.g., decrease in symptom onset or severity, improved sleep, or decrease in symptom intensity)
Horizant

For state-mandated plans in Illinois or other states where applicable: Step therapy requirements do NOT apply. Beginning January 1, 2026, step therapy requirements or use of the authorization of alternative covered medications in a manner that effectively creates a step therapy requirement will not be imposed.

Prior Authorization (Initial Authorization)

Length of Approval: 6 Month(s)
For diagnosis of Postherpetic Neuralgia (PHN)

  • Diagnosis of postherpetic neuralgia (PHN)
    • AND
  • One of the following [A]:
    • Patient has tried and had an inadequate response to a dose of at least 1,800 mg of generic gabapentin
      • OR
    • History of intolerance to generic gabapentin
Horizant

Prior Authorization (Reauthorization)

Length of Approval: 12 Month(s)
For diagnosis of Postherpetic Neuralgia (PHN)

  • Patient has experienced an improvement in PHN disease symptoms (e.g., decrease in pain severity)

  • Guideline ID
    GL-466191

  • Formulary
    Premium

  • Effective date
    Jan 1, 2026

  • P&T approval date

P & T Revisions

2025-12-10, 2025-12-04, 2025-01-20, 2024-01-29, 2023-02-28, 2022-02-08, 2021-03-03, 2020-02-19

  1. Horizant Prescribing Information. Arbor Pharmaceuticals, LLC. Atlanta, GA. August 2022.
  2. Silber MH, Buchfuhrer MJ, Earley CJ, Koo BB, Manconi M, Winkelman JW; Scientific and Medical Advisory Board of the Restless Legs Syndrome Foundation. The Management of Restless Legs Syndrome: An Updated Algorithm. Mayo Clin Proc. 2021 Jul;96(7):1921-1937. doi: 10.1016/j.mayocp.2020.12.026.
  3. Attal N, Cruccu G, Baron R, et al. EFNS guidelines on the pharmacological treatment of neuropathic pain: 2010 revision. Eur J of Neurol. 2010 Sep;17(9):1113-e88.
  4. Johnson RW and Rice AS. Clinical Practice. Postherpetic neuralgia. N Engl J Med. 2014 Oct 16;371(16):1526-33.
  1. While Horizant (gabapentin enacarbil) may improve patient convenience (twice daily rather than three times daily dosing), generic gabapentin is a more well-established, cost-effective therapy for PHN. The use of Horizant (gabapentin enacarbil) should be reserved for patients who have experienced treatment failure or intolerance to generic gabapentin. [3, 4]
  • 2025-12-10: No criteria changes, added IL statute operational note.
  • 2025-12-04: No criteria changes, added IL statute operational note.
  • 2025-01-20: 2025 annual review. No clinical changes.
  • 2024-01-29: Annual Review, no criteria changes
  • 2023-02-28: Annual Review - removal of step through ropinirole/pramipexole for RLS
  • 2022-02-08: Annual Review - No criteria changes
  • 2021-03-03: 2021 Annual Review, no changes to criteria.
  • 2020-02-19: 2020 Annual Review, no changes to criteria.