generation run 2026-04-28
60 min completedmodel pipeline-v5plan not recordedrun/a58effcd…Selection
Verification
- record
- seen / partial
- working
The model's own caveats
- no_rct_taper_evidence
- bravo_protocol_not_gabapentin_specific
Reproduce
- inputs
- 42 source keys (listed under Sources)
- plan
- not recorded — template version, prompt hash and git SHA are written from 2026-09 onward
- model
- pipeline-v5
- streams
- none — agent transcripts are persisted from 2026-09 onward
20 searches — query, source, results, what was kept and why
| # | source | query | seen | kept | rationale |
|---|---|---|---|---|---|
| 1 | PubMed | gabapentin tolerance analgesic anticonvulsant mechanism cellular | 8 | 1 | Tolerance mechanism paper |
| 2 | PubMed | gabapentin mechanism of action alpha-2-delta calcium channel pharmacology | 10 | 4 | Core pharmacology papers |
| 3 | PubMed | gabapentin pharmacokinetics bioavailability absorption human | 10 | 3 | Key human PK data |
| 4 | PubMed | gabapentin postherpetic neuralgia randomized controlled trial efficacy | 8 | 3 | Systematic review evidence for efficacy |
| 5 | PubMed | gabapentin overdose toxicity death case report | 2 | 1 | Sole case of gabapentin-only fatality |
| 6 | PubMed | gabapentin dependence withdrawal syndrome abuse misuse | 7 | 4 | Dependence and withdrawal evidence |
| 7 | ClinicalTrials.gov | gabapentin pain anxiety epilepsy | 3 | 1 | Selected completed phase 4 trial |
| 8 | PubChem | gabapentin | 1 | 1 | Primary chemical identity verification |
| 9 | OpenAlex | gabapentin mechanism alpha-2-delta calcium channel | 10 | 2 | Highly-cited mechanistic paper |
| 10 | PubMed | gabapentin opioid interaction respiratory depression overdose death | 3 | 3 | Critical interaction/safety data |
| 11 | PubMed | gabapentin Cochrane review postherpetic neuralgia diabetic neuropathy | 8 | 2 | Highest-quality systematic review evidence |
| 12 | PubMed | PMID 7600909 | 1 | 1 | Fundamental PK data |
| 13 | PubMed | gabapentin opioid interaction respiratory depression overdose death | 3 | 3 | Critical safety/interaction papers |
| 14 | WebSearch | gabapentin scheduling Australia Canada legal status | 10 | 1 | Legal status in additional jurisdictions |
| 15 | WebSearch | gabapentin legal status scheduling UK USA controlled substance history | 10 | 2 | Legal status data not in academic databases |
| 16 | PubMed | gabapentin pregabalin comparison pharmacokinetics | 2 | 1 | Definitive PK comparison study |
| 17 | PubMed | PMID 8621444 | 1 | 1 | Seminal pharmacology discovery |
| 18 | PubMed | gabapentin withdrawal symptoms discontinuation syndrome | 2 | 2 | Withdrawal documentation |
| 19 | WebSearch | gabapentin Satzinger discovery synthesis 1975 Parke-Davis FDA approval 1993 | 10 | 1 | Historical data not in modern academic databases |
| 20 | WebSearch | gabapentin LD50 lethal dose animal mouse rat toxicity DrugBank FDA | 10 | 1 | Toxicity data not separately published |
88 claims by section — every cited sentence, checked against its source
safety26 · 20 ok
The first reported fatality attributed to gabapentin alone involved a 62-year-old woman with depression whose postmortem peripheral blood concentration was 88 µg/mL — approximately 4–44× the therapeutic range of 2–20 µg/mLsupported
First reported death due solely to gabapentin toxicity. 62-year-old woman, postmortem peripheral blood gabapentin 88 µg/mL. No other significant toxic drugs. j.1556-4029.2011.01798.x
Claim in safety — inconclusiveinconclusiveworking →
A population-based nested case-control study confirmed this association at a population levelsupported
Population-based nested case-control study: co-prescription of gabapentin with opioids significantly increases risk of opioid-related death. journal.pmed.1002396
Gabapentinoid use by heroin users substantially increases overdose risk.supported
Gabapentinoids potentiate heroin effects and increase overdose risk. add.13843
No adverse fetal effects were observed in mice (up to 3,000 mg/kg) or rats (up to 1,500 mg/kg)supported
No adverse fetal effects in mice (up to 3000 mg/kg) or rats (up to 1500 mg/kg). pmid:7867910
The FDA issued a class-wide warning in December 2008 for all antiepileptic drugs, including gabapentin, regarding increased risk of suicidal ideation and behaviorsupported
FDA December 2008 warning: all AEDs associated with increased suicidal ideation/behavior. Gabapentin specifically named. s11916-011-0199-x
Claim in safety — inconclusiveinconclusiveworking →
Tolerance: Animal data demonstrate that repeated gabapentin administration produces α2δ-1 subunit downregulation in thalamus and spinal dorsal horn, directly reducing the drug's own target densitysupported
α2δ-1 down-regulation in thalamus/spinal dorsal horn associated with GBP insensitivity after repeated administration in rat model. s12264-015-0008-3
Physical dependence: Documented with prolonged use, characterized by a withdrawal syndrome on abrupt discontinuationsupported
Three case reports of withdrawal symptoms after abrupt gabapentin discontinuation. Recommends tapering, especially at high doses. pmid:11479399
Physical dependence: Documented with prolonged use, characterized by a withdrawal syndrome on abrupt discontinuationsupported
Review of case reports on gabapentin abuse, dependence, and withdrawal. 1060028015620800
Only 4 published cases of behavioral dependence on gabapentinoids without prior substance use disorder history have been identified — all involving pregabalin, none gabapentinsupported
Found only 4 cases of behavioral dependence without prior SUD; all pregabalin. psyd.2018.142
In populations with opioid use disorder, gabapentin misuse prevalence reaches approximately 26%, compared with 4% in non-OUD populations.supported
26% of patients with OUD reported gabapentin misuse vs 4% without OUD (p<0.0001). pmid:26887855
Gradual taper is recommended; one severe case required an 18-month taper.supported
32-year-old female... developed severe dependence and withdrawal requiring 18-month slow taper using BRAVO Protocol. 10550887.2021.1907502
Population-level data confirm that gabapentin co-prescription with opioids significantly increases opioid-related mortalitysupported
Population-based nested case-control study: co-prescription of gabapentin with opioids significantly increases risk of opioid-related death. journal.pmed.1002396
Among heroin users, gabapentinoid polydrug use substantially increases overdose risksupported
Gabapentinoids potentiate heroin effects and increase overdose risk. add.13843
Claim in safety — inconclusiveinconclusiveworking →
No pharmacokinetic interaction occurs — gabapentin does not affect CYP3A4 (the primary metabolic pathway for most benzodiazepines)supported
Gabapentin, vigabatrin, and levetiracetam are devoid of significant CYP enzyme inducing or inhibiting properties in humans. pmid:11030437
Claim in safety — inconclusiveinconclusiveworking →
Claim in safety — inconclusiveinconclusiveworking →
Claim in safety — inconclusiveinconclusiveworking →
Opioid co-use: Contraindicated or requires strict clinical supervision due to compounded respiratory depression risk.supported
Co-prescription of gabapentin with opioids significantly increases risk of opioid-related death. journal.pmed.1002396
Opioid co-use: Contraindicated or requires strict clinical supervision due to compounded respiratory depression risk.supported
Gabapentinoids potentiate heroin effects and increase overdose risk. add.13843
Renal impairment: Dose reduction is mandatory, as gabapentin clearance is directly proportional to creatinine clearancesupported
Gabapentin cleared via renal excretion proportional to creatinine clearance (CrCL). Dosing adjustments required for renal impairment. j.clinthera.2011.12.004
History of substance use disorder: Elevated misuse risk, particularly in individuals with opioid use disorder (26% misuse prevalence vs 4% in non-OUD populations)supported
26% of patients with OUD reported gabapentin misuse vs 4% without OUD (p<0.0001). pmid:26887855
Suicidal ideation: Per the FDA class-wide antiepileptic drug warning, patients with depression or suicidal ideation require monitoring during gabapentin therapy.supported
FDA December 2008 warning: all AEDs associated with increased suicidal ideation/behavior. Gabapentin specifically named. s11916-011-0199-x
Animal studies show no teratogenicity at moderate doses, but maternal toxicity occurred at high doses in rabbitssupported
No adverse fetal effects in mice (up to 3000 mg/kg) or rats (up to 1500 mg/kg). Rabbits at 1500 mg/kg: maternal toxicity, one death, four aborted. pmid:7867910
pharmacology18 · 13 ok
Claim in pharmacology — inconclusiveinconclusiveworking →
Claim in pharmacology — inconclusiveinconclusiveworking →
The functional consequence of α2δ-1 binding is inhibition of anterograde trafficking of the subunit to presynaptic terminals, which reduces calcium influx and neurotransmitter release at hyperexcitable synapsessupported
Gabapentinoids inhibit anterograde trafficking of alpha2delta-1 to presynaptic terminals, reducing neurotransmitter release and spinal sensitization. jneurosci.0356-09.2009
In neuropathic pain states, peripheral nerve injury causes >17-fold upregulation of α2δ-1 expression in dorsal root ganglia ipsilateral to injury — an upregulation that precedes the onset of allodyniasupported
>17-fold increase in alpha2delta subunit in DRGs ipsilateral to nerve injury preceding allodynia onset. jneurosci.21-06-01868.2001
Electrophysiological studies in rat dorsal root ganglion neurons demonstrate gabapentin inhibits whole-cell calcium channel current with an IC50 of 167 nMsupported
Gabapentin IC50 167 nM for inhibiting Ca2+ channel current in rat DRG neurons via alpha2delta subunit. pmid:11786502
Effects are neuron-type-specific across spinal cord and higher brain centers, with a number needed to treat (NNT) averaging 3–8 across neuropathic pain indications.supported
Gabapentinoids bind alpha2delta-1 and alpha2delta-2; only alpha2delta-1 implicated in neuropathy. NNT 3-8 across neuropathies. prp2.205
Bioavailability falls from approximately 60% at 900 mg/day to approximately 33% at 3,600 mg/daysupported
Bioavailability drops 60% to 33% as dose increases 900-3600 mg/day. 11536200-000000000-00000
Peak plasma concentration (Tmax) occurs at 3–4 hours after oral administrationsupported
Gabapentin Tmax 3-4 hours (oral). 11536200-000000000-00000
Population pharmacokinetic modeling describes a one-compartment model with lag time of approximately 0.311 hourssupported
One-compartment model; ... lag time 0.311 h. s10928-017-9549-6
Plasma protein binding is less than 3%supported
Plasma protein binding <3%. pmid:7600909
Plasma protein binding is less than 3%supported
Not protein-bound. 11536200-000000000-00000
Volume of distribution is approximately 81 L in healthy subjects.supported
Vd 81.0 L. s10928-017-9549-6
Elimination half-life is 5–7 hours in humanssupported
Half-life ~6 hours. 11536200-000000000-00000
Claim in pharmacology — inconclusiveinconclusiveworking →
Claim in pharmacology — inconclusiveinconclusiveworking →
Gabapentin does not induce or inhibit any major human hepatic CYP isoenzymes (CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP3A4), resulting in an exceptionally clean drug–drug interaction profile from a pharmacokinetic standpoint.supported
Gabapentin, vigabatrin, and levetiracetam are devoid of significant CYP enzyme inducing or inhibiting properties in humans. pmid:11030437
Elimination is directly proportional to creatinine clearance, and dose reduction is mandatory in renal impairment.supported
Gabapentin cleared via renal excretion proportional to creatinine clearance (CrCL). Dosing adjustments required for renal impairment. j.clinthera.2011.12.004
Claim in pharmacology — inconclusiveinconclusiveworking →
pharmacokinetic-detail11 · 9 ok
Genetic polymorphisms in ABCB1 (specifically 2677G>T/A) significantly influence the absorption rate constantsupported
ABCB1 2677G>T/A affects absorption. s10928-017-9549-6
Sources: ; .supported
One-compartment model; bioavailability 68.8% at 300mg... Oral clearance 11.1 L/h, Vd 81.0 L. s10928-017-9549-6
Sources: ; .supported
Gabapentin Tmax 3-4 hours (oral), saturable nonlinear absorption. Bioavailability drops 60% to 33%. 11536200-000000000-00000
Claim in pharmacokinetic-detail — inconclusiveinconclusiveworking →
Minimal protein binding (<3%) eliminates displacement interactions with highly bound drugssupported
Plasma protein binding <3%. pmid:7600909
The large volume of distribution (~81 L) indicates extensive tissue distribution.supported
Vd 81.0 L. s10928-017-9549-6
Claim in pharmacokinetic-detail — inconclusiveinconclusiveworking →
Sources: ; ; .supported
Oral bioavailability: 79% in mice/rats at 50 mg/kg, 80% in dogs, 40% in monkeys. Plasma protein binding <3%. pmid:7600909
Sources: ; ; .supported
One-compartment model; bioavailability 68.8% at 300mg, 62.7% at 400mg, 47.1% at 800mg. s10928-017-9549-6
Dose reduction is mandatory in patients with reduced renal functionsupported
Dosing adjustments required for renal impairment. j.clinthera.2011.12.004
Dose reduction is mandatory in patients with reduced renal functionsupported
CL 2.93 L/h in elderly NH patients (lower than general population, reflecting reduced renal function). s12248-016-0022-z
summary10 · 7 ok
Claim in summary — inconclusiveinconclusiveworking →
Absorption is saturable and dose-dependent: bioavailability falls from approximately 60% at 900 mg/day to approximately 33% at 3,600 mg/day.supported
Bioavailability drops 60% to 33% as dose increases 900-3600 mg/day. 11536200-000000000-00000
Its molecular target — the α2δ-1 subunit of voltage-gated calcium channels — was not identified until 1996, two decades after synthesis.supported
First identification of alpha2delta subunit as the gabapentin binding site. pmid:8621444
Gabapentin binds the α2δ-1 subunit of high-voltage-activated calcium channels, inhibiting whole-cell calcium current with an IC50 of 167 nM in dorsal root ganglion neuronssupported
Gabapentin IC50 167 nM for inhibiting Ca2+ channel current in rat DRG neurons via alpha2delta subunit. pmid:11786502
Cryo-EM structures reveal a binding pocket in the dCache1 domain of CaVα2δ-1 that completely encapsulates the moleculesupported
Cryo-EM structure of the gabapentin-bound CaV1.2/CaVβ3/CaVα2δ-1 channel reveals a binding pocket in the dCache1 domain that completely encapsulates gabapentin. s41594-023-00951-7
The drug inhibits anterograde trafficking of α2δ-1 to presynaptic terminals, reducing neurotransmitter release in sensitized pain pathways.supported
Gabapentinoids inhibit anterograde trafficking of alpha2delta-1 to presynaptic terminals, reducing neurotransmitter release and spinal sensitization. jneurosci.0356-09.2009
Claim in summary — inconclusiveinconclusiveworking →
The principal mortality risk is pharmacodynamic: co-use with opioids significantly increases opioid-related deathsupported
Co-prescription of gabapentin with opioids significantly increases risk of opioid-related death. journal.pmed.1002396
Claim in summary — inconclusiveinconclusiveworking →
Tolerance involves α2δ-1 subunit downregulation in thalamus and spinal cord, though no controlled human study has quantified the reset timelinesupported
α2δ-1 down-regulation in thalamus/spinal dorsal horn associated with GBP insensitivity after repeated administration in rat model. s12264-015-0008-3
neuroscience7 · 3 ok
Claim in neuroscience — inconclusiveinconclusiveworking →
By binding α2δ-1 subunits and preventing their trafficking to the presynaptic membrane, gabapentin reduces high-voltage-activated calcium channel density at synapses that have undergone pathological sensitizationsupported
Gabapentinoids inhibit anterograde trafficking of alpha2delta-1 to presynaptic terminals, reducing neurotransmitter release and spinal sensitization. jneurosci.0356-09.2009
In neuropathic pain models, peripheral nerve injury triggers >17-fold upregulation of α2δ-1 in ipsilateral dorsal root ganglion neurons, creating a pathological excess of presynaptic calcium channelssupported
>17-fold increase in alpha2delta subunit in DRGs ipsilateral to nerve injury preceding allodynia onset. jneurosci.21-06-01868.2001
Claim in neuroscience — inconclusiveinconclusiveworking →
Claim in neuroscience — inconclusiveinconclusiveworking →
Tolerance mechanisms in humans: Animal data demonstrate α2δ-1 downregulation with chronic gabapentin use, but no controlled human study has quantified the timeline or extent of clinical tolerance development.supported
α2δ-1 down-regulation in thalamus/spinal dorsal horn associated with GBP insensitivity after repeated administration in rat model. s12264-015-0008-3
Claim in neuroscience — inconclusiveinconclusiveworking →
clinical-evidence6 · 6 ok
A meta-analysis of 6 randomized controlled trials (769 patients) demonstrated that gabapentin reduces visual analog scale (VAS) pain scores at 24 and 48 hours after total knee arthroplasty and reduces morphine consumption (mean difference −8.28 mg at 24 hours)supported
Meta-analysis of 6 studies (769 patients): gabapentin superior pain relief at 24h and 48h; reduced cumulative morphine consumption at 24h (MD -8.28 mg). md.0000000000003673
Meta-analyses show a small but significant reduction in alcohol withdrawal severity with gabapentinsupported
Meta-analyses of RCTs: gabapentin reduces alcohol withdrawal severity and percentage of heavy drinking days, but small effect. jcp.20f13775
The Cochrane systematic review (2017) provides the highest-quality evidence for gabapentin efficacy in chronic neuropathic painsupported
Cochrane systematic review: gabapentin ≥1200mg/day provides substantial benefit (≥50% pain relief) vs placebo in postherpetic neuralgia (RR 1.8) and painful diabetic neuropathy (RR 1.9). 14651858.cd007938.pub4
An umbrella review of gabapentinoid meta-analyses found that 14 of 16 reviews rated "critically low" quality by AMSTAR 2 criteria; the Cochrane review was the exception.supported
Umbrella review of 16 meta-analyses: 14 'critically low' quality by AMSTAR 2. Best evidence: Cochrane review. fcp.70052
Current evidence supports gabapentin only as a second-line agent for alcohol-related disorders.supported
Recommend as second-line after standard therapies. ccjm.86a.18128
Gabapentin demonstrates anxiolytic effects in clinical populations and is used off-label for generalized anxiety disorder and social phobiasupported
Controlled trial evidence for gabapentin in social phobia. Gabapentin shows potential as anxiolytic in off-label use. pmid:15456335
receptor-pharmacology6 · 5 ok
Gee and colleagues first isolated and characterized the [³H]gabapentin-binding protein in 1996 from pig cerebral cortex, purifying it 1,022-foldsupported
Binding protein isolated from pig cerebral cortex, purified 1022-fold. [3H]gabapentin is the first pharmacological agent described interacting with an alpha2delta subunit. pmid:8621444
Brown and colleagues subsequently developed a refined radioligand binding assay using [³H]leucine that confirmed the high-affinity interaction with the purified α2δ subunit from porcine brain.supported
Purification of alpha2delta Ca2+ channel subunit from porcine brain. Novel binding assay using L-[3H]leucine/L-isoleucine validated. Confirms gabapentin binds alpha2delta with high affinity. pmid:9451509
Chen, Mondal, and Minor published the cryo-EM structure of gabapentin bound to the brain/cardiac CaV1.2/CaVβ3/CaVα2δ-1 channel complex in 2023supported
Cryo-EM structure of the gabapentin-bound CaV1.2/CaVβ3/CaVα2δ-1 channel reveals a binding pocket in the dCache1 domain. s41594-023-00951-7
Claim in receptor-pharmacology — inconclusiveinconclusiveworking →
Beyond acute channel modulation, gabapentin exerts a distinct chronic mechanism: inhibition of α2δ-1 anterograde trafficking from neuronal cell bodies to presynaptic terminalssupported
Gabapentinoids inhibit anterograde trafficking of alpha2delta-1 to presynaptic terminals, reducing neurotransmitter release and spinal sensitization. jneurosci.0356-09.2009
In neuropathic pain states, α2δ-1 is pathologically upregulated (>17-fold in spinal nerve-ligation models), leading to excessive presynaptic calcium channel expression, increased neurotransmitter release, and spinal sensitizationsupported
>17-fold increase in alpha2delta subunit in DRGs ipsilateral to nerve injury preceding allodynia onset. jneurosci.21-06-01868.2001
comparative-pharmacology2 · 2 ok
Only 4 published cases of behavioral dependence on gabapentinoids without prior substance use disorder history have been identified — all involving pregabalin, none gabapentinsupported
Found only 4 cases of behavioral dependence without prior SUD; all pregabalin. psyd.2018.142
Source: .supported
A comparison of the pharmacokinetics and pharmacodynamics of pregabalin and gabapentin. 11536200-000000000-00000
history1 · 1 ok
The landmark identification of the α2δ subunit of voltage-gated calcium channels as the binding target came only in 1996, when Gee and colleagues isolated and characterized the [³H]gabapentin-binding protein from pig cerebral cortex.supported
First identification of alpha2delta subunit as the gabapentin binding site. Binding protein isolated from pig cerebral cortex, purified 1022-fold. pmid:8621444
legal-status1 · 1 ok
This patchwork reflects an ongoing tension between gabapentin's clinical utility as a non-opioid analgesic and mounting pharmacovigilance signals of misuse-related harm.supported
Pharmacovigilance analysis using FDA AERS for gabapentin misuse signals. j.drugalcdep.2019.107709