Source-backed half-life profile
Gabapentin half-life calculator
Gabapentin is a clean-looking curve that still depends heavily on renal-clearance context.
Every curve begins at 100%. No dose or measured body concentration is assumed.
X-axis: elapsed time. Y-axis: modeled percentage of the relative starting point remaining. The shaded band shows the reported half-life range. This is a mathematical visualization, not a personal concentration estimate.
What a careful reader should notice first
The representative half-life is helpful for a basic model, but patient factors can matter more here than the neatness of the equation suggests.
Source angle
Labels are especially useful when they describe renal function and dosing-population context.
Do not use it for
Do not use the page for medication adjustment, sedation, withdrawal, or combination-risk decisions.
Best next step
Compare with pregabalin and read clearance-versus-distribution.
Gabapentin: evidence and interpretation notes
Six hours describes normal renal clearance
Gabapentin labeling reports an elimination half-life of 5 to 7 hours in adults and notes that the value is not materially changed by dose or repeated administration when renal function is otherwise comparable. HalfLifeDB uses the midpoint, six hours, because the label provides a clear supported interval rather than a universal observation.
Gabapentin is not appreciably metabolized in humans and is excreted through the kidneys as unchanged drug. This makes renal clearance, rather than hepatic metabolism, the central variable behind the page’s uncertainty.
| Evidence source | What it contributes | Important limit |
|---|---|---|
| DailyMed capsule labeling | The 5-to-7-hour range, unchanged renal excretion, and special-population context | A label cannot estimate an individual visitor’s renal function |
| Blum renal-function study | Direct measurements in 60 people across a broad range of renal function | It was a controlled single-exposure study, not a model for every circumstance |
| PubChem identity record | Compound identity | It does not establish the six-hour curve |
The renal-function study shows how far the number can move
Blum and colleagues studied 60 participants with varying renal function, collecting plasma and urine measurements for an extended period. Apparent oral and renal clearance decreased as renal function diminished, while peak timing and half-life increased. Gabapentin clearance was linearly related to creatinine clearance.
The labeling summarizes the size of that difference: mean half-life was about 6.5 hours in participants with creatinine clearance above 60 mL/min and approximately 52 hours in those below 30 mL/min. That is too large a shift to represent with a narrow generic uncertainty band.
Why the calculator stops at a normal-function midpoint
Entering kidney measurements or dialysis status would make this look like a dose-adjustment tool, which it is not. The six-hour curve is a reference profile for the normal-function range described by labeling. It should not be applied to a person with known or suspected renal impairment.
The chart also does not predict sedation, withdrawal, accumulation, or combination effects. Its useful lesson is that a clean-looking half-life can still depend on one dominant physiological pathway, and gabapentin’s pathway is renal clearance.
Reading this curve
HalfLifeDB uses 6 h as a representative input for Gabapentin. In the simplified model, about 6.3% remains after 24 hours and about 3% remains after five half-lives, or roughly 30 h.
This sits in the same-day range. The chart is useful for seeing the bend of the curve across a day or two, but it should not be treated as a personal clock. The curve is relative: it does not estimate a person's measured concentration, effects, impairment, or time to clearance.
gabapentinoid context
Gabapentinoid half-life estimates often look straightforward, but renal clearance, formulation, and repeated dosing can strongly affect practical interpretation.
- The curve is not a sedation, withdrawal, or dose-adjustment guide.
- Renal function can be central to source interpretation.
- Repeated-use accumulation is not modeled by the single-dose chart.
Gabapentin timeline checkpoints
| Elapsed time | Modeled remaining | Reading note |
|---|---|---|
| 12 h | 25.0% | Long-tail portion of the model |
| 24 h | 6.25% | Low modeled remainder, not a clearance guarantee |
| 2.0 days | 0.39% | Low modeled remainder, not a clearance guarantee |
| 3.0 days | 0.02% | Low modeled remainder, not a clearance guarantee |
| 5.0 days | 0.00% | Low modeled remainder, not a clearance guarantee |
Nearby profiles by half-life
These entries sit near Gabapentin within the gabapentinoid group when sorted by representative half-life. That makes them curve comparisons, not statements about equal potency, effects, or risk.
No nearby published profiles are available in this category.
Pharmacokinetics at a glance
| Representative half-life | 6 h |
|---|---|
| Reported range | 5 h to 7 h |
| Curve type | Normalized, first-order decline |
Selection note: Product labeling reports a 5-to-7-hour elimination half-life in adults and much longer values as renal function declines; the curve uses the midpoint.
Sources and evidence context
A linked record is not automatically proof of the displayed value. Study, labeling, review, and compound identity sources serve different purposes; notes below identify limitations when they are known.
- Official labeling DailyMed label: Gabapentin capsule.Official labeling supporting the 5-to-7-hour range, unchanged renal excretion, and the strong effect of reduced renal function.
- Research abstract Blum RA et al. Pharmacokinetics of gabapentin in subjects with various degrees of renal function (1994).Three-center study of 60 subjects directly examining how diminished renal function changes clearance and half-life.
- Identity record PubChem Compound Summary: Gabapentin.Compound identity record; background only.
What this page does not answer
- It does not estimate impairment, intoxication, or fitness to drive.
- It does not predict urine, blood, saliva, or hair test results.
- It does not model repeated exposure, tolerance, withdrawal, or interactions.
- It does not replace clinician, pharmacist, toxicologist, or emergency guidance.
Continue with context
- All substance profiles
- Browse the gabapentinoid group
- Compare this curve
- Clearance and volume of distribution
- Bioavailability, route, and formulation
- Active metabolites and parent compounds
- First-order vs nonlinear kinetics
- Detection windows vs half-life
- Reading labels and source quality
Read the medical disclaimer, methodology, and profile review log before using the model for comparison.