Gabapentin Dosing for ESRD Pruritus from Hyperphosphatemia
Recommended Post-Hemodialysis Dosing Regimen
Administer gabapentin 100-300 mg after each hemodialysis session (three times weekly) for uremic pruritus in ESRD patients, starting at 100 mg and titrating upward based on response. 1, 2
Starting Dose and Titration Strategy
Begin with 100 mg administered immediately after each hemodialysis session (three times weekly) to minimize adverse events in this population. 3
Titrate up to 200 mg three times weekly after dialysis if inadequate response after 3-4 weeks. 4
Maximum dose is 300 mg three times weekly if needed, though most patients respond to lower doses. 1, 4
These doses are markedly lower than non-ESRD populations due to reduced renal clearance and accumulation risk. 1, 4
Timing of Administration
Always administer gabapentin after hemodialysis sessions, not before, to avoid premature drug removal during dialysis. 1
Hemodialysis removes approximately 35% of gabapentin dose with a dialysis clearance of 142 mL/min. 5
Gabapentin elimination half-life is approximately 4 hours during hemodialysis but extends to 132 hours on non-dialysis days in anuric patients. 5
Expected Efficacy Timeline
Significant reductions in pruritus severity (VAS score reductions >50%) typically occur by 3-8 weeks of treatment. 3
In clinical trials, mean pruritus scores decreased from 81.11 to 6.44 points on a visual analog scale with gabapentin treatment. 6
Pre-Treatment Optimization Required
Before initiating gabapentin, ensure the following are optimized, as these address the underlying hyperphosphatemia and uremic pruritus: 1, 2
Ensure adequate dialysis with target Kt/V of approximately 1.6. 1, 2
Normalize calcium-phosphate balance and control parathyroid hormone levels to accepted ranges. 1, 2
Provide emollients liberally for xerosis (dry skin), which lowers the threshold for itch. 1, 2
Safety Monitoring and Common Adverse Effects
Gabapentin is associated with dose-dependent risks of altered mental status (31-50% increased hazard), falls (26-55% increased hazard), and fractures (38% increased hazard) in hemodialysis patients. 7
Common side effects include mild drowsiness, dizziness, and fatigue, occurring in at least 26% of patients. 1, 3
Approximately 2-3% of patients discontinue gabapentin due to intolerability. 3
Monitor closely for sedation, especially if patient is on concurrent beta-blockers for heart failure, which compounds sedation risk. 1
Critical Pitfalls to Avoid
Do not use standard dosing recommendations for non-ESRD patients—the FDA label recommends 100-300 mg daily for CrCl <15 mL/min, but post-dialysis dosing (100-300 mg three times weekly) is more appropriate for hemodialysis patients. 8, 1
Avoid cetirizine and other antihistamines as they are ineffective specifically for uremic pruritus despite efficacy in other conditions. 1, 2, 4
Avoid long-term sedating antihistamines (diphenhydramine, hydroxyzine) except in palliative care due to increased dementia risk. 1, 2
Do not abruptly discontinue gabapentin—taper gradually over minimum 1 week if discontinuation is needed. 8
Alternative Treatments if Gabapentin Fails or Is Not Tolerated
Topical capsaicin 0.025% cream applied four times daily to affected areas provides marked relief in 82% of patients (14 of 17 in trials). 1, 2
Broad-band UVB phototherapy is effective for many patients with uremic pruritus. 1, 2
Topical doxepin may be considered for severe cases but must be limited to 8 days, 10% body surface area, and maximum 12 g daily. 2