Gabapentin (sold under the brand name Neurontin, among others) is a medication which is used to treat partial seizures, neuropathic pain, hot flashes, and restless legs syndrome. It is recommended as one of a number of first-line medications for the treatment of neuropathic pain caused by diabetic neuropathy, postherpetic neuralgia, and central neuropathic pain. About 15% of those given gabapentin for diabetic neuropathy or postherpetic neuralgia have a measurable benefit. Gabapentin is taken by mouth.
Common side effects of gabapentin include sleepiness and dizziness. Serious side effects include an increased risk of suicide, aggressive behavior, and drug reaction with eosinophilia and systemic symptoms. It is unclear if it is safe during pregnancy or breastfeeding. Lower doses are recommended in those with kidney disease associated with a low glomerular filtration rate. Gabapentin is a gabapentinoid: it has a structure similar to that of the neurotransmitter γ-aminobutyric acid (GABA) and acts by inhibiting certain calcium channels.
Gabapentin was first approved for use in 1993. It has been available as a generic medication in the United States since 2004. The wholesale price in the developing world as of 2015 was about US$10.80 per month; in the United States, it was US$100 to US$200. In 2016 it was the 11th most prescribed medication in the United States with more than 44 million prescriptions. During the 1990s, Parke-Davis, a subsidiary of Pfizer, began using a number of illegal techniques to encourage physicians in the United States to use gabapentin for off-label (unapproved) uses. They have paid out millions of dollars to settle lawsuits regarding these activities.