Tablets should be swallowed whole and should not be cut, crushed, or chewed.
Tablets should be taken with food.
HORIZANT is not interchangeable with other gabapentin products because of differing pharmacokinetic profiles [see Warnings and Precautions (5.3)].
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 [see Adverse Reactions (6.1)].
If the dose is not taken at the recommended time, the next dose should be taken the following day as prescribed.
Postherpetic Neuralgia
The recommended dosage of HORIZANT is 600 mg twice daily. HORIZANT should be initiated at a dose of 600 mg in the morning for 3 days of therapy, then increased to 600 mg twice daily (1,200 mg/day) on day four. In the 12-week principal efficacy study, additional benefit of using doses greater than 1,200 mg a day was not demonstrated, and these higher doses resulted in an increase in adverse reactions [see Adverse Reactions (6.1)].
If the dose is not taken at the recommended time, skip this dose, and the next dose should be taken at the time of the next scheduled dose.
Renal Impairment
Dosing of HORIZANT is adjusted in accordance with renal function, as represented by creatinine clearance [see Clinical Pharmacology (12.3)]. 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 |
|
|
| ≥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 |
In patients with stable renal function, CrCl can be estimated using the equation of Cockcroft and Gault:
-
- for males: CrCl = (140-age)(weight)/[(72)(SCr)]
-
- for females: CrCl = (0.85)(140-age)(weight)/[(72)(SCr)]
where age is in years, weight is in kilograms, and SCr is serum creatinine in mg/dL.
