What is the renal dosing adjustment for Gabapentin (Gabapentin) in patients with Impaired renal function?

From the Guidelines

Gabapentin dosing in patients with renal impairment should be adjusted based on creatinine clearance (CrCl) to minimize the risk of toxicity and optimize efficacy. The dosing recommendations for gabapentin in patients with renal impairment are as follows:

• For patients with a CrCl of 60 mL/min or greater, the standard dosing of 300-1200 mg three times daily can be used.
• For CrCl between 30-59 mL/min, reduce the dose to 200-700 mg twice daily.
• For CrCl between 15-29 mL/min, administer 200-700 mg once daily.
• For CrCl less than 15 mL/min, give 100-300 mg once daily.
• Patients on hemodialysis should receive a maintenance dose of 100-300 mg after each 4-hour hemodialysis session, with a supplemental dose based on their pre-dialysis level 1. Dose adjustment is necessary because gabapentin is primarily eliminated unchanged through the kidneys, and reduced renal function leads to decreased drug clearance and potential toxicity. Symptoms of gabapentin toxicity include dizziness, somnolence, ataxia, and confusion. Regular monitoring of renal function is important when using gabapentin in patients with kidney disease, and doses should be adjusted accordingly if renal function changes. Key considerations in renal dosing of gabapentin include:
• Nonlinear pharmacokinetics due to saturable absorption, requiring careful titration 1
• Dose-dependent dizziness and sedation, which can be reduced by starting with lower dosages and titrating cautiously 1
• Importance of regular monitoring of renal function to adjust doses accordingly and minimize the risk of toxicity.

From the FDA Drug Label

1. 3 Dosage Adjustment in Patients with Renal Impairment Dosage adjustment in patients 12 years of age and older with compromised renal function or undergoing hemodialysis is recommended, as follows TABLE 1 Gabapentin Tablets Dosage Based on Renal Function Renal Function Creatinine Clearance (mL/min) Total Daily Dose Range (mg/day) Dose Regimen (mg) ≥60 900-3600 300 TID 400 TID 600 TID 800 TID 1200 TID

   30-59 400-1400 200 BID 300 BID 400 BID 500 BID 700 BID 15-29 200-700 200 QD 300 QD 400 QD 500 QD 700 QD 15a 100-300 100 QD 125 QD 150 QD 200 QD 300 QD Post-Hemodialysis Supplemental Dose (mg)b Hemodialysis 125b 150b 200b 250b 350b TID = Three times a day; BID = Two times a day; QD = Single daily dose a For patients with creatinine clearance <15 mL/min, reduce daily dose in proportion to creatinine clearance (e.g., patients with a creatinine clearance of 7. 5 mL/min should receive one-half the daily dose that patients with a creatinine clearance of 15 mL/min receive). b Patients on hemodialysis should receive maintenance doses based on estimates of creatinine clearance as indicated in the upper portion of the table and a supplemental post-hemodialysis dose administered after each 4 hours of hemodialysis as indicated in the lower portion of the table

The recommended renal dosing for gabapentin is as follows:

• For patients with creatinine clearance ≥60 mL/min, the total daily dose range is 900-3600 mg/day, with a dose regimen of 300-1200 mg three times a day.
• For patients with creatinine clearance >30-59 mL/min, the total daily dose range is 400-1400 mg/day, with a dose regimen of 200-700 mg two times a day.
• For patients with creatinine clearance >15-29 mL/min, the total daily dose range is 200-700 mg/day, with a dose regimen of 200-700 mg once daily.
• For patients with creatinine clearance <15 mL/min, the daily dose should be reduced in proportion to creatinine clearance.
• For patients on hemodialysis, a supplemental post-hemodialysis dose should be administered after each 4 hours of hemodialysis, as indicated in the table 2.

From the Research

Renal Dosing for Gabapentin

• The provided studies do not directly address the renal dosing of gabapentin, but rather focus on pregabalin and gabapentin use in patients with decreased kidney function 3, 4, 5, 6, 7.
• However, it can be inferred that gabapentin, like pregabalin, requires dosage adjustment in patients with decreased renal function, as both medications are primarily cleared by the kidney 4, 5.
• A study comparing the efficacy and safety of pregabalin and gabapentin in uremic pruritus found that gabapentin was associated with a higher incidence of adverse effects, such as sedation, nausea, and blurred vision, compared to pregabalin 6.
• Another study found that gabapentin produced a significant reduction in itching intensity, but was associated with a higher incidence of fatigue, dizziness, and somnolence compared to pregabalin 7.
• The exact renal dosing for gabapentin is not specified in the provided studies, but it is recommended to use gabapentin judiciously in patients with decreased kidney function and to consider dosage adjustments based on the patient's creatinine clearance (CrCl) 4, 5.
• Patients with a CrCl <60 mL/min may require a reduced dose of gabapentin, and those with a CrCl <30 mL/min may require further reductions in dosage 4.
• However, more research is needed to determine the optimal dosing of gabapentin in patients with decreased renal function 5.