Gabapentin and Visual Problems

Dr Charles Shephard (ME Association)

Gabapentin (Neurontin) has become established as a useful drug in the treatment of moderate to severe neuropathic pain. This is a term that refers to pain that often has a burning, searing or stabbing quality to it rather than pain this is primarily felt in the muscles or joints.
Anecdotal reports from a significant number of people with ME/CFS who have moderate to severe neuropathic pain indicate that Gabapentin can be very helpful in some cases and is generally well tolerated.

As with any drug that is genuinely effective, Gabapentin does sometimes have side-effects. Minor effects that are fairly frequently reported include dizziness, somnolence, headache, weight gain and diarrhoea. However, serious side-effects are more unusual. This weeks issue of the British Medical Journal reports on a case of visual field defect associated with the use of Gabapentin in a 52 year old woman who had been taking between 400mg twice daily and 800mg three times daily over a period of several months. She then started to complain about short episodes of disturbed vision and dizziness. The drug was reduced and stopped.

The authors speculate that the explanation could be due to the fact that drugs such as Gabapentin, which increase the activity of a chemical called GABA (gamma aminobutyric acid) in the brain may lead to toxic reactions in the retina at the back of the eye. As a result, caution be exercised in the use of Gabapentin in anyone with a past or current history of eye disease, especially if this involves retinal disease or loss of vision.