Horizant Dosage

Generic name: GABAPENTIN ENACARBIL 300mg
Dosage form: tablet, extended release
Drug class: Gamma-aminobutyric acid analogs

Medically reviewed by Drugs.com. Last updated on Apr 28, 2025.

Dosage and Administration Overview

Tablets should be swallowed whole and should not be cut, crushed, or chewed.

Tablets should be taken with food.

HORIZANT is not substitutable with other gabapentin products because of differing pharmacokinetic profiles [ see Warnings and Precautions (5.3)].

Recommended Dosage for Restless Legs Syndrome

The recommended dosage for HORIZANT is 600 mg once daily at about 5 PM. A daily dose of 1,200 mg provided no additional benefit compared with the 600-mg dose, but caused an increase in adverse reactions .

If the dose is not taken at the recommended time, the next dose should be taken the following day as prescribed.

Recommended Dosage for Renal Impairment

Dosing of HORIZANT is adjusted in accordance with renal function, as represented by creatinine clearance . Target dose regimens are listed in Table 1 and Table 2.

Table 1. Dosage of HORIZANT for Patients With Restless Legs Syndrome in Accordance With Creatinine Clearance
Creatinine Clearance (mL/min)	Target Dose Regimen
≥60	600 mg per day
30 – 59	Start at 300 mg per day and increase to 600 mg as needed
15 – 29	300 mg per day
<15	300 mg every other day
<15 on hemodialysis	Not recommended

Table 2. Dosage of HORIZANT for Patients With Postherpetic Neuralgia in Accordance With Creatinine Clearance
Creatinine Clearance (mL/min)	Titration	Maintenance	Tapering
* Based on tolerability and efficacy
≥60	600 mg in AM for 3 days	600 mg twice daily	600 mg in AM for 1 week
30 – 59	300 mg in AM for 3 days	300 mg twice daily. Increase to 600 mg twice daily as needed *	Reduce current maintenance dose to once daily in AM for 1 week
15 – 29	300 mg in AM on Day 1 and Day 3	300 mg in AM. Increase to 300 mg twice daily if needed *	If taking 300 mg twice daily, reduce to 300 mg once daily in AM for 1 week. If taking 300 mg once daily, no taper needed.
<15	None	300 mg every other day in AM. Increase to 300 mg once daily in AM if needed *	None
<15 on hemodialysis	None	300 mg following every dialysis. Increase to 600 mg following every dialysis if needed *	None