What is the recommended dosage of gabapentin (Neurontin) for a patient with End-Stage Renal Disease (ESRD)?

Gabapentin Dosing in ESRD Patients

For patients with end-stage renal disease (ESRD), gabapentin should be dosed at 100-300 mg once daily, with a supplemental dose of 125-350 mg administered after each 4-hour hemodialysis session. 1

Initial Dosing Strategy

• For anuric patients or those with creatinine clearance <15 mL/min, start with 100-300 mg once daily 1
• The specific daily dose within this range (100,125,150,200, or 300 mg) should be selected based on the indication and patient tolerance 1
• An alternative approach is to use a loading dose of 300-400 mg initially, followed by maintenance dosing of 200-300 mg after each hemodialysis session 2

Post-Hemodialysis Supplementation

Critically important: A supplemental dose must be given after each dialysis session because approximately 35% of gabapentin is removed during a 4-hour hemodialysis treatment 2

• The post-hemodialysis supplemental dose ranges from 125-350 mg, depending on the baseline daily dose 1
• If the daily dose is 100 mg, give 125 mg post-dialysis 1
• If the daily dose is 300 mg, give 350 mg post-dialysis 1
• Hemodialysis clearance of gabapentin is approximately 142 mL/min, representing about 93% of creatinine clearance through the dialyzer 2

Critical Pharmacokinetic Considerations

The elimination half-life of gabapentin increases dramatically from 5-9 hours in normal renal function to 132 hours in anuric patients 3, 2

• During hemodialysis, the half-life decreases to approximately 4 hours 2
• Plasma gabapentin concentrations increase approximately 30% during the first 2 hours after hemodialysis due to drug redistribution from tissues 2
• For peritoneal dialysis patients, the elimination half-life is approximately 41 hours with intensive continuous cycling, which is faster than without dialysis but still substantially prolonged 4

Peritoneal Dialysis Specific Dosing

• Peritoneal dialysis provides gabapentin clearance at approximately 94% of urea clearance 4
• While less efficient than hemodialysis, intensive peritoneal dialysis (2-L exchanges every 2 hours) can effectively clear gabapentin over 36-48 hours 4
• The same conservative daily dosing (100-300 mg once daily) should be applied to peritoneal dialysis patients 1

Common Pitfalls and Safety Warnings

Failure to adjust gabapentin dosing in ESRD leads to severe neurotoxicity including encephalopathy, altered mental status, dizziness, falls, and fractures 3, 5

• Approximately 19% of dialysis patients in the US receive gabapentin, and its use is associated with increased risk of altered mental status, falls, and fractures when not properly dosed 5
• Symptoms of gabapentin toxicity in dialysis patients include encephalopathy, muscle weakness, extremity pain, and defecation urgency 3, 6
• These neurological symptoms can prompt unnecessary extensive diagnostic workups (including brain CT scans) when the actual cause is simply gabapentin overdose 5
• Symptoms typically resolve within 3 days of drug discontinuation with continued dialysis 3

Monitoring Recommendations

• Drug level monitoring should be considered in dialysis patients on gabapentin to avoid unintended overdose, though it is rarely utilized in practice 5
• Maximum plasma concentrations in ESRD patients receiving 600 mg are approximately 5.6-5.8 μg/mL 6
• Monitor closely for signs of neurotoxicity, particularly during dose initiation or escalation 6

Dose Titration Approach

• Start at the lowest end of the dosing range (100 mg once daily) 1
• Titrate slowly based on clinical response and tolerability 1
• Do not exceed 300 mg once daily as the maintenance dose in anuric patients 1
• Always remember the post-dialysis supplemental dose for hemodialysis patients 1, 2