Gabapentin
Gabapentin, sold under the brand name Neurontin among others, is an anticonvulsant medication primarily used to treat partial seizures and neuropathic pain. It is commonly used medication for the treatment of neuropathic pain caused by diabetic neuropathy, postherpetic neuralgia, and central pain. It is moderately effective: about 30–40% of those given gabapentin for diabetic neuropathy or postherpetic neuralgia have a meaningful benefit. Sleepiness and dizziness are the most common side effects. Serious side effects include an increased risk of suicide, respiratory depression, and allergic reactions. Lower doses are recommended in those with kidney disease. Gabapentin acts by decreasing activity of a subset of calcium channels. Gabapentin was first approved for use in 1993. It has been available as a generic medication in the United States since 2004. In 2020, it was the tenth most commonly prescribed medication in the United States, with more than 49 million prescriptions. During the 1990s, Parke-Davis, a subsidiary of Pfizer, used a number of illegal techniques to encourage physicians in the United States to prescribe gabapentin for unapproved uses. They have paid out millions of dollars to settle lawsuits regarding these activities. Gabapentin is recommended for use in focal seizures and neuropathic pain. Gabapentin is widely prescribed off-label in the US and UK, for example, for the treatment of non-neuropathic pain, anxiety disorders and bipolar disorder. There is concern regarding gabapentin's off-label use due to the lack of strong scientific evidence for its efficacy in multiple conditions and its proven side effects. Gabapentin is approved for the treatment of focal seizures; however, it is not effective for generalized epilepsy. Gabapentin is recommended as a first-line treatment for chronic neuropathic pain by various medical authorities. This is a general recommendation applicable to all neuropathic pain syndromes except for trigeminal neuralgia, where it may be used as a second- or third-line agent.
