By Brett R. Stacey, MD, and Pamela Campbell, MD
Comprehensive Pain Center, Oregon Health & Science University, Portland, Oregon
In addition to neuropathic pain, pregabalin has been shown to be effective in fibromyalgia pain, the pain after spinal cord injury, and anxiety.
Gabapentin and pregabalin have similar side effects. The most common are dizziness and sedation. Patients placed on gabapentin usually experience side effects as they titrate slowly up to an effective dose, which is roughly 1,200 to 3,600 mg per day. Conversely, for patients taking pregabalin the typical starting dose of 150 mg per day can be helpful.. The range of effective doses is 150 to 600mg per day. For both medications, side effects tend to decrease over time. Less common side effects include peripheral edema and weight gain especially when taken in combination with oral hypoglycemics.
Pregabalin is categorized by the FDA as a schedule V drug, the lowest level of surveillance from the FDA. This means it is a controlled substance.
The earliest reports of gabapentin's use in treating pain were case reports of a few patients with CRPS who improved with gabapentin. Unfortunately, there have never been larger, controlled studies that definitively prove the benefits of gabapentin. As of yet, there are no studies in CRPS for pregabalin. CRPS and all other nerve pathology other than PHN and DPN are considered off label since studies in nerve pain have only been done in these specific conditions.