Off-label use exposes patients to adverse effects and generally is not supported by evidence.
The only conditions for which gabapentinoid drugs are FDA-approved to manage pain are postherpetic neuralgia (both gabapentin and pregabalin [Lyrica]) and diabetic neuropathy, spinal cord injury, and fibromyalgia (pregabalin only). Nevertheless, use of these drugs has tripled during the past 15 years. This increase likely reflects gabapentinoid use for managing non–FDA-approved pain conditions, in part to avoid opioid use. In this review, researchers identified 34 placebo-controlled randomized trials (with ≈4200 patients) of gabapentinoids for noncancer, non–FDA-approved pain conditions. Most trials’ durations were 4 to 12 weeks.
Results of the review were as follows:
- Only weak evidence supports use of gabapentin for diabetic neuropathy (only pregabalin is approved for this indication).
- Minimal evidence supports use of gabapentin for nondiabetic painful neuropathies.
- Studies of gabapentinoids for managing low back pain or sciatica have been largely negative.
- Only minimal evidence supports a clinically meaningful benefit of off-label gabapentin use for fibromyalgia (for which pregabalin is approved).
- Both gabapentin and pregabalin are approved for managing postherpetic neuralgia, but both are used often for acute zoster pain, for which studies have shown no benefit.
- A small number of studies of gabapentinoid use for other pain syndromes (e.g., traumatic nerve injury, complex regional pain syndrome, burn injury, sickle cell pain) showed no clinically important benefits.