Gabapentin (Neurontin) was developed as an anti-epilepsy drug, but is now more commonly used to treat pain, particularly pain due to nerve damage (neuropathy). It is similar in structure to the brain transmitter gamma-aminobutyric acid (GABA) but its mode of action is unclear. It is manufactured by Parke-Davis, a subsidiary of Pfizer.

Gabapentin is sometimes prescribed as a mood stabiliser for patients with bipolar disorder, although its effectiveness for this condition is uncertain. It may also be effective in treating anxiety disorders, including obsessive-compulsive disorder. However, Pfizer has been criticised for marketing the drug for these disorders, even though it is not approved for these uses.

A double-blind randomised controlled trial has shown that gabapentin is effective in reducing the pain and sleep disturbances caused by HIV-associated neuropathy. After four weeks of treatment, patients taking gabapentin had lower pain levels than patients taking placebo^[1].

Gabapentin has few side-effects, although it can cause dizziness, drowsiness and swelling of the hands and feet. In children, it can cause mood disturbances, concentration problems and hyperactivity.

Gabapentin does not interact with any currently available protease inhibitors or non-nucleoside reverse transcriptase inhibitors (NNRTIs).