From the FDA Drug Label
Gabapentin elimination half-life is 5 to 7 hours and is unaltered by dose or following multiple dosing. The half-life of gabapentin is 5 to 7 hours 1.
- In adults with normal renal function, the elimination half-life of gabapentin is approximately 5 to 7 hours.
- The half-life may be longer in patients with renal impairment, with a mean half-life ranging from about 6.5 hours to 52 hours in patients with creatinine clearance <30 mL/min 1.
From the Research
The half-life of gabapentin is approximately 6-8 hours in patients with normal renal function, as reported in the study published in 1995 2. This means it takes about 6-8 hours for the concentration of gabapentin in the bloodstream to decrease by half after it has been absorbed. For patients with impaired kidney function, the half-life can be significantly longer, potentially extending to more than the normal range in those with severe renal impairment, as the kidneys are the primary route of gabapentin elimination. Some key points to consider about gabapentin half-life include:
- The half-life determines the dosing frequency, which is typically three times daily for most patients.
- Due to this relatively short half-life in patients with normal kidney function, gabapentin needs to be taken consistently at regular intervals to maintain therapeutic blood levels.
- Missing doses can lead to decreased effectiveness or withdrawal symptoms.
- When discontinuing gabapentin, it should be tapered gradually over at least one week rather than stopped abruptly to avoid withdrawal effects, which is a consideration directly related to its half-life properties. It's also worth noting that more recent studies, such as the one published in 2024 3, have focused on the evaluation of gabapentin and pregabalin use in hospitalized patients with decreased kidney function, but the fundamental pharmacokinetic properties of gabapentin, including its half-life, remain consistent with earlier findings 2, 4.