What is the recommended conversion dose from gabapentin to Lyrica (pregabalin)?

Gabapentin to Pregabalin (Lyrica) Conversion

When converting from gabapentin to pregabalin, use a ratio of approximately 6:1, meaning 600 mg of gabapentin is equivalent to 100 mg of pregabalin. 1

Conversion Guidelines

The conversion from gabapentin to pregabalin should follow these steps:

1. Calculate equivalent dose: Use the 6:1 ratio (gabapentin:pregabalin)

   • Example: 1800 mg/day of gabapentin ≈ 300 mg/day of pregabalin
   • Example: 3600 mg/day of gabapentin ≈ 600 mg/day of pregabalin

2. Initial dosing and titration:

   • Start with a lower dose of pregabalin (75 mg twice daily) regardless of previous gabapentin dose
   • Titrate up to the target dose over 2-4 weeks based on efficacy and tolerability
   • Maximum recommended pregabalin dose is 600 mg/day divided into two or three doses 1

3. Dose adjustment for renal impairment:

   Creatinine Clearance (mL/min)	Total Daily Dose Range (mg/day)
   ≥60	300-600
   30-59	150-300
   15-29	75-150
   <15	25-75

Clinical Considerations

• Pharmacological differences: While both medications are α2δ calcium channel ligands, pregabalin has higher bioavailability (>90%) and more predictable absorption compared to gabapentin 2

• Efficacy comparison: Pregabalin may provide more consistent pain relief at lower doses compared to gabapentin due to its linear pharmacokinetics and higher potency 3, 2

• Dosing schedule: Pregabalin can be administered twice daily, whereas gabapentin often requires three daily doses for optimal effect 1, 4

• Onset of action: Pregabalin may show earlier onset of efficacy (as early as day 2) compared to gabapentin 2

Common Pitfalls to Avoid

• Abrupt conversion: Don't switch immediately from full-dose gabapentin to full-dose pregabalin. This increases risk of side effects.

• Inadequate dosing: Underdosing pregabalin after conversion may lead to loss of pain control. The 6:1 ratio is a guideline, but individual response varies.

• Overlooking side effects: Monitor for common side effects that occur with both medications:

  • Dizziness
  • Somnolence
  • Peripheral edema
  • Weight gain 1

• Ignoring renal function: Both medications are primarily excreted unchanged by the kidneys, requiring dose adjustment in renal impairment 1, 2

• Discontinuation issues: Both medications should be tapered gradually to avoid withdrawal symptoms 5

Special Considerations

• Pregabalin is classified as a Schedule V controlled substance in the United States due to potential for abuse 1

• Consider monitoring for depression or suicidal thoughts with pregabalin therapy 5

• Elderly patients typically require lower doses and slower titration of both medications 1