Neuropathic pain is pain coming from damaged nerves. It is different from pain messages carried along healthy nerves from damaged tissue (for example from a fall, a cut, or arthritic knee). Neuropathic pain is treated by different medicines than pain from damaged tissue. Medicines like paracetamol or ibuprofen are not effective in treating neuropathic pain, while medicines that are sometimes used to treat depression or epilepsy can be very effective in some people with neuropathic pain. Our knowledge about fibromyalgia is even less advanced, but fibromyalgia can respond to the same medicines as neuropathic pain.
Topiramate is a medicine used to treat epilepsy, and so it might be a useful medicine for neuropathic pain or fibromyalgia.
On 8 May 2013, we performed searches to look for clinical trials on the use of topiramate to treat neuropathic pain or fibromyalgia. We found four studies of reasonable quality that tested topiramate against placebo for a number of weeks. Almost all of the 1684 people in the studies had painful limbs because of damaged nerves caused by diabetes.
Topiramate did not help the pain and was no different from placebo except in causing more side-effects, which made many more people withdraw from the studies early. About 3 people in 10 withdrew because of side-effects with topiramate compared with 1 in 10 with placebo.
Topiramate has not been shown to work as a pain medicine in diabetic neuropathy.