Neurontin is typically eliminated from the system within 30 to 42 hours after administration. The anti-convulsant medication has a half-life of five to seven hours, with just 1.5 percent of the medication remaining in the system after six half-lives, according to RxList.
Neurontin is eliminated exclusively via the kidneys; the process is often slower in elderly patients and those with renal impairment. Hemodialysis may also be used to remove the substance and other fluid and waste products from the blood.
In avoiding withdrawal symptoms, patients are encouraged to taper off usage over a minimum of one week; magnesium supplements are also effective.