Gabapentin is a powerful medicine



We found moderate-quality evidence that gabapentin 1200 mg or more daily, taken by mouth, had a significant effect on the pain of some people with moderate or severe post-herpes zoster (shingles) or diabetic neuropathic pain.


Neuropathic pain is attributed to damage to nerves. They are different from the messages of pain carried along healthy nerves by damaged tissue (for example, from a fall, cut, or arthritic knee). Neuropathic pain is often treated with different drugs than pain caused by damaged tissue and treated with pain relievers. Medications, sometimes used for depression or epilepsy, may be effective in some people with neuropathic pain. One of them is gabapentin. Our definition of a good result was a person who experienced high levels of pain relief and was able to continue taking the drug without any side effects causing them to stop taking the treatment.

Study characteristics

We searched for clinical trials using gabapentin to treat neuropathic pain in adults in January 2017. We found 37 studies that met the inclusion criteria. They randomized 5,914 participants to treatment with gabapentin, placebo, or other drugs. The studies lasted 4 to 12 weeks. Most studies reported beneficial outcomes that people with neuropathic pain consider important. Results were mainly available for pain after shingles and pain due to nerve damage in diabetes.

Main results

Post-shingles pain was reduced by half or more in 3 out of 10 people with gabapentin and in 2 out of 10 people with placebo. The pain was reduced by a third or more in 5 out of 10 people with gabapentin and in 3 out of 10 with placebo. Pain caused by diabetes was reduced by half or more in 4 out of 10 people with gabapentin and 2 in 10 with placebo. The pain was reduced by a third or more in 5 out of 10 with gabapentin and 4 out of 10 with placebo. There was no reliable evidence for other types of neuropathic pain.

Side effects were more common with gabapentin (6 out of 10) than with placebo (5 out of 10). Dizziness, sleepiness, water retention, and problems walking were each about 1 in 10 people who took gabapentin. Serious side effects were rare and did not differ between gabapentin and placebo. Slightly more people stopped taking gabapentin because of the side effects.

Gabapentin is helpful for some people with chronic neuropathic pain. However, it is not possible to predict who the drug will help and who will not. To find out, based on current knowledge, it is best to carry out a short attempt at therapy.

Quality of the evidence

Most of the evidence was of moderate quality. This means that the research gives a good indication of the likely effect. The likelihood that the effect will be significantly different is moderate.