Duration of Pregabalin Therapy for Fibromyalgia
Pregabalin should be continued long-term (at least 6 months) in patients who achieve meaningful pain relief (≥30% reduction), as discontinuation leads to rapid loss of therapeutic response within 3 weeks. 1
Evidence for Long-Term Continuation
The strongest evidence comes from the FREEDOM trial, which demonstrated that patients who initially responded to pregabalin and continued treatment maintained their response significantly longer than those switched to placebo 1. Specifically:
- Half of patients switched to placebo lost therapeutic response by Day 19, while half of those continuing pregabalin still maintained response at the end of the 26-week study period 1
- At 6 months, only 32% of pregabalin-treated patients lost therapeutic response compared to 61% on placebo 1
- A second randomized withdrawal study confirmed these findings, showing median time to loss of response was 58 days on pregabalin versus 22 days on placebo 2
Practical Duration Recommendations
Initial trial period:
- Titrate pregabalin over 3 weeks to the optimal dose (300-450 mg/day divided twice daily) 3, 1
- Assess response at 6 weeks using ≥30% pain reduction as the threshold for meaningful benefit 1
Long-term continuation:
- Continue indefinitely in responders, as fibromyalgia is a chronic condition requiring ongoing management 4
- Durability of effect has been demonstrated for at least 6 months in clinical trials 1, 5
- Regular reassessment every 4-8 weeks is essential to evaluate ongoing efficacy using pain scores and functional status 4
Important Caveats
- Most patients (approximately 50%) will not achieve adequate response to pregabalin monotherapy, even at optimal doses 5
- During the initial 6-week open-label phase, 17% of patients discontinued due to treatment-related adverse events, primarily dizziness and somnolence 1
- The number needed to harm (NNH) for withdrawal due to adverse events is 12 at therapeutic doses 3
- Pregabalin must be discontinued gradually to avoid withdrawal symptoms 6
When to Discontinue
- If no or inadequate pain relief (<30% reduction) occurs after 6 weeks at target dosage, switch to an alternative first-line medication such as duloxetine or amitriptyline 4
- If partial relief is achieved, consider adding another first-line medication from a different class rather than discontinuing 4
- Strong opioids should never be added for fibromyalgia, as they are not recommended and have not demonstrated benefits 7, 4