Does pregabalin (lyrica) cause less dizziness than gabapentin (neurontin)?

Pregabalin vs Gabapentin: Dizziness as a Side Effect

Pregabalin does not cause less dizziness than gabapentin; both medications have similar rates of dizziness as a side effect. 1, 2

Side Effect Profiles

• Both pregabalin and gabapentin commonly cause dizziness, with pregabalin causing dizziness in 23-46% of patients 2
• The most common side effects for both medications include dizziness, somnolence, dry mouth, and constipation 1
• Dizziness is dose-dependent for both medications and can be managed by dose reduction or slower titration 3
• Both medications can also cause peripheral edema and weight gain, particularly in elderly patients 1, 4

Pharmacokinetic Differences

• While the side effect profiles are similar, pregabalin has more predictable absorption and linear pharmacokinetics compared to gabapentin 2, 5
• Pregabalin is absorbed more rapidly (peak plasma concentration within 1 hour) compared to gabapentin (3-4 hours) 5
• Gabapentin exhibits saturable absorption (nonlinear), making its pharmacokinetics less predictable, while pregabalin has linear absorption with plasma concentrations increasing proportionately with dose 5
• The absolute bioavailability of gabapentin drops from 60% to 33% as dosage increases from 900 to 3600 mg/day, while pregabalin maintains ≥90% bioavailability regardless of dose 5

Dosing Considerations

• Pregabalin's starting dose is typically 50 mg three times daily or 75 mg twice daily, with maximum dose of 600 mg/day 1, 2
• Gabapentin is usually started at 100-300 mg at bedtime or 100-300 mg three times daily, with maximum dose of 3600 mg/day 1
• Both medications require dosage reduction in patients with renal impairment 1, 2
• For elderly patients, lower starting doses and slower titration are recommended for both medications to minimize side effects, particularly dizziness 1, 2

Clinical Implications

• When switching between these medications, consider that the side effect profiles are similar, particularly regarding dizziness 2, 5
• To minimize dizziness with either medication:
  • Start with lower doses (pregabalin: 25-50 mg/day; gabapentin: 100-200 mg/day) 1
  • Implement slow dose escalation with adequate intervals to monitor effects 1
  • Consider divided dosing to minimize peak-related side effects 1
• For patients experiencing intolerable dizziness with one medication, switching to the other may not necessarily reduce this side effect 1, 2, 3

Monitoring Recommendations

• Monitor all patients for dizziness, somnolence, and other neurological side effects, especially during dose titration 1
• Be particularly cautious in elderly patients who may be more susceptible to falls due to dizziness 1, 2
• Consider dose reduction rather than discontinuation if dizziness occurs, as these side effects are typically dose-dependent 3