Pregabalin Dosing for Shingles in Patients Who Cannot Tolerate Gabapentin
For patients with shingles who cannot tolerate gabapentin, the recommended dosing of pregabalin is 75 to 150 mg twice daily, or 50 to 100 mg three times daily (150-300 mg/day total). 1
Initial Dosing and Titration
- Start pregabalin at 75 mg twice daily or 50 mg three times daily (150 mg/day) 2, 1
- Increase to 300 mg/day after 3-7 days based on efficacy and tolerability 2, 1
- For patients who do not experience sufficient pain relief after 2-4 weeks at 300 mg/day, and who tolerate the medication well, the dose may be increased up to 600 mg/day (300 mg twice daily or 200 mg three times daily) 1
Maximum Dosing Considerations
- Although pregabalin has been studied at 600 mg/day for postherpetic neuralgia, doses higher than 300 mg/day are not consistently more effective and are associated with more adverse effects 2, 1
- Reserve dosing above 300 mg/day only for patients with ongoing pain who are tolerating 300 mg/day well 1
Administration Guidelines
- Pregabalin can be given with or without food 1
- When discontinuing pregabalin, taper gradually over a minimum of 1 week to avoid withdrawal symptoms 1
Renal Dosing Adjustments
- Since pregabalin is eliminated primarily by renal excretion, dose adjustment is required in patients with reduced renal function 2, 1
- For patients with creatinine clearance below 60 mL/min, reduce the dose accordingly 1
Advantages of Pregabalin over Gabapentin
- Pregabalin has linear pharmacokinetics, making dosing more straightforward than gabapentin's nonlinear kinetics 2, 3
- Pregabalin may provide analgesia more quickly than gabapentin due to more efficient gastrointestinal absorption 3, 4
- An adequate trial of pregabalin requires approximately 4 weeks, compared to 2 months or more for gabapentin 2, 3, 4
Efficacy in Postherpetic Neuralgia
- Studies show that pregabalin can provide at least a 50% reduction in pain scores for one-third to one-half of patients with postherpetic neuralgia at a dose of 600 mg/day 5
- In patients with inadequate response to gabapentin, pregabalin might be considered as an alternative treatment 2
- Some comparative studies suggest pregabalin may have better efficacy compared to other treatments like amitriptyline in postherpetic neuralgia 6
Common Side Effects and Monitoring
- Most common adverse effects include dizziness, somnolence, peripheral edema, and weight gain 2, 5
- Neuropsychological reactions (dizziness and drowsiness) are the most frequently reported side effects 5
- Monitor for visual field restrictions, which have been reported in clinical trials 5
- Side effects are typically dose-dependent; starting with lower doses and titrating slowly can improve tolerability 2