Only one high-quality clinical trial has looked at gabapentin (Neurontin, others) as a fibromyalgia treatment. In that study, the drug reduced participants' reported pain, fatigue and sleep disruption more effectively than did a placebo.
Gabapentin has not been approved by the Food and Drug Administration (FDA) for the treatment of fibromyalgia, although some doctors may prescribe it off-label for such use. The FDA has, however, approved a similar drug — pregabalin (Lyrica) — for fibromyalgia treatment.
Gabapentin and pregabalin were originally approved to treat certain types of epilepsy and nerve pain. Both drugs work by limiting the release of pain-communicating chemicals by nerve cells in the brain and spinal cord.
Because gabapentin is available in generic form, it may be less expensive than pregabalin. But you have to take gabapentin three or four times a day, which makes it less convenient than pregabalin, taken in two daily doses. The most common side effects of both drugs are dizziness and drowsiness.