What is the Lyrica (pregabalin) equivalent to gabapentin 1200mg daily?

Pregabalin Equivalent to Gabapentin 1200mg Daily

The equivalent dose of Lyrica (pregabalin) to gabapentin 1200mg daily is approximately 150mg daily (75mg twice daily). 1

Conversion Rationale

The conversion between gabapentin and pregabalin is based on their pharmacokinetic and pharmacodynamic properties:

1. Pharmacokinetic Differences:

   • Gabapentin has nonlinear (zero-order) absorption with bioavailability decreasing from 60% to 33% as dosage increases 2
   • Pregabalin has linear (first-order) absorption with consistent ≥90% bioavailability regardless of dose 2
   • Pregabalin reaches maximum plasma concentration within 1 hour, while gabapentin takes 3-4 hours 2

2. Dosing Equivalence:

   • According to clinical guidelines, gabapentin is typically titrated up to 3600mg/day (in 3 divided doses) 1
   • Pregabalin's equivalent maximum dosage is 600mg/day (200mg 3 times daily or 300mg twice daily) 1
   • This creates an approximate 6:1 ratio (3600mg:600mg) between gabapentin and pregabalin

3. Calculation for 1200mg Gabapentin:

   • Using the 6:1 ratio: 1200mg gabapentin ÷ 6 = 200mg pregabalin daily
   • However, the most recent guideline recommends starting pregabalin at 150mg/day (75mg twice daily) when converting from lower gabapentin doses 1

Clinical Considerations

Efficacy Comparison

Recent evidence suggests pregabalin may have superior efficacy compared to gabapentin:

• A 2024 meta-analysis found pregabalin demonstrated superior and faster efficacy in alleviating neuropathic pain than gabapentin 3
• Pregabalin showed better improvements in quality of life measures and resulted in lower opioid consumption 3

Pharmacokinetic Advantages of Pregabalin

• More predictable dose-response relationship due to linear pharmacokinetics 2
• Faster onset of action (peak plasma levels in 1 hour vs. 3-4 hours for gabapentin) 2
• More consistent bioavailability regardless of dose 2

Dosing Considerations

• When switching from gabapentin to pregabalin:
  • Start with pregabalin 150mg/day (75mg twice daily) 1
  • Can be titrated up to 300mg/day after 3-7 days if needed 1
  • Maximum dose is 600mg/day (in divided doses) 1

Adverse Effects

• Both medications have similar adverse effect profiles, primarily neuropsychological reactions (dizziness and drowsiness) 4
• Both can cause weight gain and peripheral edema, especially in elderly patients 4
• Some evidence suggests gabapentin may have a higher incidence of nausea and vomiting compared to pregabalin 3

Common Pitfalls to Avoid

1. Dosing Errors: Don't assume a 1:1 conversion ratio between gabapentin and pregabalin
2. Renal Adjustment: Both medications require dose reduction in patients with renal impairment 1
3. Abrupt Discontinuation: Avoid sudden discontinuation of either medication to prevent withdrawal symptoms
4. Overlooking Drug Interactions: While both have limited drug interactions, be aware of potential additive CNS depression with other medications

Remember that an adequate trial of pregabalin typically requires 4 weeks, compared to 2 months or more for gabapentin 1. This faster titration and onset of action may be advantageous in clinical practice.