I am taking both gabapentin and pregabalin for neuropathic pain; should I continue both, how should I taper them, and what adjunct therapies such as NSAIDs or physical therapy should I use?

Do Not Use Gabapentin and Pregabalin Together

You should not routinely combine gabapentin and pregabalin for neuropathic pain, as both are calcium channel α2δ ligands with the same mechanism of action, and there is no high-quality evidence supporting superior efficacy or safety of this combination over optimized monotherapy. 1, 2

Why This Combination Is Problematic

Both medications bind to the same α2δ subunit of voltage-gated calcium channels and inhibit the same excitatory neurotransmitter release pathways 1. Using them together:

• Increases side effects without proven additional benefit: The dose-dependent adverse effects (dizziness, sedation, peripheral edema, weight gain) will compound 1, 3
• Lacks guideline support: The 2010 Mayo Clinic neuropathic pain guidelines explicitly state that "the efficacy of adjunctive pregabalin in patients taking gabapentin has not been evaluated in controlled trials. Consequently, dosing recommendations for the use of pregabalin with gabapentin cannot be offered" 1
• No FDA approval for combination use: The pregabalin FDA label does not support concurrent gabapentin use 2

What You Should Do Instead

Step 1: Optimize Monotherapy First

Choose pregabalin over gabapentin if you're going to use only one:

• Pregabalin has linear pharmacokinetics and more straightforward dosing 1
• It may provide analgesia more quickly (effective at 150 mg/day initial dose) 1
• Maximum dose: 600 mg/day, though 300 mg/day is often sufficient 1, 2
• Allow 4 weeks for adequate trial 1

If already on gabapentin:

• Ensure you've reached adequate doses (up to 3600 mg/day in divided doses) 1
• Allow 3-8 weeks for titration plus 2 weeks at maximum tolerated dose 1

Step 2: Add a Different Mechanism Drug

If monotherapy fails, combine with a medication that works through a different pathway 4, 5:

Best-supported combinations:

• Gabapentinoid + Duloxetine (SNRI): Different mechanism, good evidence for neuropathic pain, fewer drug interactions 4, 6, 5

  • Start duloxetine 30 mg daily × 1 week, then 60 mg daily 1

• Gabapentinoid + Tricyclic antidepressant (nortriptyline/desipramine): Useful for sleep disturbance and insufficient pain relief 4

  • Start 25 mg at bedtime, titrate by 25 mg every 3-7 days 1
  • Get screening ECG if patient >40 years old 1

• Gabapentinoid + Topical lidocaine 5% patches: For well-localized neuropathic pain with allodynia 1

  • Maximum 3 patches daily for 12-18 hours 1

Step 3: Consider Tramadol for Breakthrough Pain

Tramadol can be added for mixed neuropathic/nociceptive pain 7:

• Start 50 mg once or twice daily
• Titrate by 50-100 mg every 3-7 days
• Maximum 400 mg/day (300 mg/day if >75 years) 1
• Provides dual mechanism (weak opioid + SNRI effects)

Step 4: Add Adjunctive Non-Pharmacologic Therapies

Physical therapy and self-management strategies should run parallel to medication adjustments 6:

• Structured exercise programs
• Cognitive-behavioral therapy for pain
• Sleep hygiene optimization

If You're Already Taking Both

Tapering Strategy

Discontinue one medication (preferably gabapentin) while optimizing the other:

1. Keep pregabalin stable at current dose
2. Taper gabapentin by 300 mg every 3-7 days to avoid withdrawal symptoms
3. Once off gabapentin, optimize pregabalin to therapeutic dose (300-600 mg/day) 2
4. Monitor for 4 weeks at optimized dose before declaring treatment failure 1

Critical Caveats

• Renal impairment: Both drugs require dose adjustment based on creatinine clearance 1, 2
• Elderly patients: Start lower, titrate slower, watch for falls risk from dizziness/sedation 1, 8
• Avoid abrupt discontinuation: Taper gradually to prevent withdrawal symptoms
• The recent meta-analysis showing benefit of gabapentinoid combinations 5 primarily studied combinations with OTHER drug classes (antidepressants, opioids), not gabapentin + pregabalin together

Bottom Line Algorithm

1. Optimize single gabapentinoid (preferably pregabalin) to maximum tolerated dose
2. If inadequate response after 4 weeks, add duloxetine or nortriptyline (different mechanism)
3. If still inadequate, consider tramadol for breakthrough pain
4. Add topical lidocaine if pain is well-localized
5. Reserve opioids for refractory cases only after comprehensive risk-benefit assessment 6

The case reports suggesting synergy between gabapentin and pregabalin 9, 10 are low-quality evidence (case series only) and should not override the lack of controlled trial data and guideline recommendations against this combination.