CurrentCentenePolicy CP PMN.240

Gabapentin ER (Gralise, Horizant) coverage policy

Defines medical necessity criteria, prior authorization requirements, dosing limits, and approval durations for gabapentin ER products Gralise and Horizant for Postherpetic Neuralgia (PHN) and Restless Legs Syndrome (RLS) across Commercial, HIM, and Medicaid lines of business.

Policy Summary

PayerCentene

PolicyGabapentin ER (Gralise, Horizant) coverage policy

Policy CodePolicy CP PMN.240

Change TypeCriteria revision and redirection; IL HIM step therapy bypass added

Effective Date09.01.20

Next Review Date

Key ActionProvider must submit chart notes, lab results, or other clinical information supporting that member met all approval criteria.

POLICY UPDATE CHANGES

Added step therapy bypass for Illinois HIM per IL HB 5395 (effective 01/01/2026)

For PHN, added requirement that member must use generic Gralise if available

Revised PHN criteria to require trial of pregabalin IR OR ER instead of both

Added note that authorization may be required for pregabalin

Updated Gralise product strengths and maximum quantity to reflect new 450, 750, 900 mg strengths

2Covered Indications

3Required prior trials

12 mo

Coverage Summary

Coverage stance: Covered with criteria. Scope: defines medical necessity criteria, prior authorization and step therapy requirements, dosing limits, and approval durations for gabapentin ER products Gralise and Horizant for Postherpetic Neuralgia (PHN) and Restless Legs Syndrome (RLS) across Commercial, HIM, and Medicaid lines of business. Covered indications: PHN (Gralise and Horizant) and RLS (Horizant only). Affected products: Gralise and Horizant. Policy effective date: 09.01.20. Last review date: 08.25.

Continuation Therapy Criteria

Other Diagnoses / Off-Label

Provider Actions

Prior Authorization

Prior authorization required

Gralise and Horizant require prior authorization. Requests must include evidence that required prior trials and age criteria are met (e.g., 30-day trial of immediate‑release generic gabapentin at ≥1,800 mg/day for PHN and trial of generic pregabalin [IR or ER] at up to maximally indicated doses unless contraindicated). Note: pregabalin itself may require authorization or redirection per this policy.

Documentation Required

Submit supporting documentation

Submit chart notes, laboratory results, or other clinical information demonstrating that the member met all approval criteria (diagnosis, age, required prior trials, dosing limits, contraindications or adverse effects to prior agents, etc.).

Billing Rule

Dose limit enforcement

Dose limits and tablet limits are enforced per product and indication:

Gralise: maximum 1,800 mg per day
Gralise: maximum 2 tablets per day
Horizant (PHN): maximum 1,200 mg per day
Horizant (PHN): maximum 2 tablets per day
Horizant (RLS): maximum 600 mg per day
Horizant (RLS): maximum 1 tablet per day

Step Therapy

Step therapy requirements

Step therapy requires failure trials of immediate‑release generic gabapentin (30 days at specified doses) and a 30‑day trial of generic pregabalin (IR or ER) at up to maximally indicated doses unless contraindicated or adverse effects occur. Material change: Illinois HIM (HIM) requests are exempt from these step therapy requirements per IL HB 5395 effective 01/01/2026.

Applicable Codes & Product Availability

Applicable NDCs / Product availabilityNDC

Gralise ER tablets strengths	ER tablets: 300 mg, 450 mg, 600 mg, 750 mg, 900 mg
Horizant ER tablets strengths	ER tablets: 300 mg, 600 mg

Background

Background: Both Gralise and Horizant are FDA-approved for management of postherpetic neuralgia (PHN); Horizant is also FDA-approved for treatment of moderate-to-severe primary restless legs syndrome (RLS) in adults. The policy notes that Gralise and Horizant are not interchangeable with other gabapentin products because of pharmacokinetic differences that affect dosing frequency. Product availability/strengths: Gralise ER tablets available in 300 mg, 450 mg, 600 mg, 750 mg, and 900 mg strengths (maximum Gralise dose 1,800 mg/day; policy also specifies a maximum of 2 tablets per day per prescribing information), and Horizant ER tablets available in 300 mg and 600 mg strengths (maximum Horizant dose 1,200 mg/day for PHN with 2 tablets/day limit; for RLS maximum 600 mg/day with 1 tablet/day limit).

Clinical Evidence & References

Evidence: Primary sources are the Gralise and Horizant Prescribing Information (April 2025). Key clinical evidence and guidance cited include a systematic review and meta-analysis in Lancet Neurology (Finnerup et al., 2015) and practice/guideline documents such as the American Academy of Neurology practice parameter for PHN and multiple RLS guidelines and systematic reviews (including AASM and AAN-related guidance and RLS practice updates).

Definitions & Thresholds

Key thresholds and definitions

Age>= 18 years

Gabapentin IR trial30 days at >= 1,800 mg/day (failure unless contraindicated)

Pregabalin trial30 days at up to maximally indicated doses (immediate‑release OR controlled‑release), unless contraindicated

Gralise maximum dose<= 1,800 mg/day

Gralise tablet limit<= 2 tablets per day

Horizant maximum dose (PHN)<= 1,200 mg/day

Horizant tablet limit (PHN)<= 2 tablets per day

Revision History

05.06.25addedLatest

Added step therapy bypass for Illinois HIM per IL HB 5395 (effective 01/01/2026). Detail: Illinois HIM requests are exempt from step therapy requirements as of 1/1/2026.

05.06.25added

For PHN, added requirement that member must use generic Gralise if available. Detail: Redirection requirement to generic gabapentin once-daily for Gralise requests unless contraindicated.

12.02.23revised