Trial Outcomes & Findings for Drug Use Investigation Of Gabapentin (NCT NCT00567268)

Last Updated: 2021-02-03

Results Overview

Clinical efficacy rate, which was defined as the percentage of participants who achieved clinical efficacy over the total number of efficacy analysis population, was presented along with the corresponding exact 2-sided 95% CI. For the basis of efficacy evaluation, frequencies of epileptic seizure were recorded for the periods during the previous 4 weeks from the treatment start date, and that from the end date of observation (12 weeks after the treatment start date, or date of which treatment was terminated before reaching 12 weeks). Clinical efficacy was assessed according to the following categories: (1) effective, (2) not effective, or (3) not assessable.

Recruitment status

COMPLETED

Target enrollment

1273 participants

Primary outcome timeframe

12 weeks

Results posted on

2021-02-03

Participant Flow

Participant milestones

Participant milestones
Measure	Gabapentin 200, 300, 400 mg Tablets The usual dosage of gabapentin in adults and children aged 13 or older was as follows: oral gabapentin 600 mg, 3 div., was administered on day 1 and an effective dose of 1200 mg, 3 div., was administered on day 2. From day 3 on, oral gabapentin 1200 mg to 1800 mg, 3 div., was administered as the maintenance dose. Subsequently, the maintenance dose was suitably adjusted depending on the symptoms (up to a maximum daily dose of 2400 mg).
Overall Study STARTED	1194
Overall Study COMPLETED	1144
Overall Study NOT COMPLETED	50

Reasons for withdrawal

Reasons for withdrawal
Measure	Gabapentin 200, 300, 400 mg Tablets The usual dosage of gabapentin in adults and children aged 13 or older was as follows: oral gabapentin 600 mg, 3 div., was administered on day 1 and an effective dose of 1200 mg, 3 div., was administered on day 2. From day 3 on, oral gabapentin 1200 mg to 1800 mg, 3 div., was administered as the maintenance dose. Subsequently, the maintenance dose was suitably adjusted depending on the symptoms (up to a maximum daily dose of 2400 mg).
Overall Study Protocol Violation	7
Overall Study Lost to Follow-up	36
Overall Study No Visit After First Day of Treatment	2
Overall Study No Drug Administration	4
Overall Study Safety Evaluation "Not Assessable"	1

Baseline Characteristics

Drug Use Investigation Of Gabapentin

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Gabapentin 200, 300, 400 mg Tablets n=1144 Participants The usual dosage of gabapentin in adults and children aged 13 or older was as follows: oral gabapentin 600 mg, 3 div., was administered on day 1 and an effective dose of 1200 mg, 3 div., was administered on day 2. From day 3 on, oral gabapentin 1200 mg to 1800 mg, 3 div., was administered as the maintenance dose. Subsequently, the maintenance dose was suitably adjusted depending on the symptoms (up to a maximum daily dose of 2400 mg).
Age, Customized <65 years	1001 participants n=93 Participants
Age, Customized >=65 years	143 participants n=93 Participants
Sex: Female, Male Female	542 Participants n=93 Participants
Sex: Female, Male Male	602 Participants n=93 Participants

PRIMARY outcome

Timeframe: 12 weeks

Population: The safety analysis population comprised of participants who had met the inclusion criteria and had taken gabapentin at least once.

A treatment-related adverse event was any untoward medical occurrence attributed to gabapentin in a participant who received gabapentin. Expectedness of the adverse event was determined according to the Japanese package insert. Relatedness to gabapentin was assessed by the sponsor (Pfizer Japan Inc.).

Outcome measures

Outcome measures
Measure	Gabapentin 200, 300, 400 mg Tablets n=1144 Participants The usual dosage of gabapentin in adults and children aged 13 or older was as follows: oral gabapentin 600 mg, 3 div., was administered on day 1 and an effective dose of 1200 mg, 3 div., was administered on day 2. From day 3 on, oral gabapentin 1200 mg to 1800 mg, 3 div., was administered as the maintenance dose. Subsequently, the maintenance dose was suitably adjusted depending on the symptoms (up to a maximum daily dose of 2400 mg).	Age >=15 and <25 Years Participants \>=15 and \<25 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=25 and <35 Years Participants \>=25 and \<35 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=35 and <45 Years Participants \>=35 and \<45 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=45 and <55 Years Participants \>=45 and \<55 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=55 and <65 Years Participants \>=55 and \<65 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=65 Years Participants \>=65 years years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert
Number of Participants With Treatment-Related Adverse Events Unexpected From Japanese Package Insert	27 participants	—	—	—	—	—	—

PRIMARY outcome

Timeframe: 12 weeks

Population: The safety analysis population comprised of participants who had met the inclusion criteria and had taken gabapentin at least once.

A treatment-related adverse event was any untoward medical occurrence attributed to gabapentin in a participant who received gabapentin. Relatedness to gabapentin was assessed by the sponsor (Pfizer Japan Inc.).

Outcome measures

Outcome measures
Measure	Gabapentin 200, 300, 400 mg Tablets n=1144 Participants The usual dosage of gabapentin in adults and children aged 13 or older was as follows: oral gabapentin 600 mg, 3 div., was administered on day 1 and an effective dose of 1200 mg, 3 div., was administered on day 2. From day 3 on, oral gabapentin 1200 mg to 1800 mg, 3 div., was administered as the maintenance dose. Subsequently, the maintenance dose was suitably adjusted depending on the symptoms (up to a maximum daily dose of 2400 mg).	Age >=15 and <25 Years Participants \>=15 and \<25 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=25 and <35 Years Participants \>=25 and \<35 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=35 and <45 Years Participants \>=35 and \<45 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=45 and <55 Years Participants \>=45 and \<55 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=55 and <65 Years Participants \>=55 and \<65 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=65 Years Participants \>=65 years years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert
Number of Participants With Treatment-Related Adverse Events	231 participants	—	—	—	—	—	—

PRIMARY outcome

Timeframe: 12 weeks

Population: The efficacy analysis population comprised of the participants who had at least one post-baseline efficacy evaluation for the clinical efficacy and seizure frequency within the safety analysis population. Participants who had disease not eligible for the survey were excluded from the efficacy analysis population.

Outcome measures

Outcome measures
Measure	Gabapentin 200, 300, 400 mg Tablets n=1045 Participants The usual dosage of gabapentin in adults and children aged 13 or older was as follows: oral gabapentin 600 mg, 3 div., was administered on day 1 and an effective dose of 1200 mg, 3 div., was administered on day 2. From day 3 on, oral gabapentin 1200 mg to 1800 mg, 3 div., was administered as the maintenance dose. Subsequently, the maintenance dose was suitably adjusted depending on the symptoms (up to a maximum daily dose of 2400 mg).	Age >=15 and <25 Years Participants \>=15 and \<25 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=25 and <35 Years Participants \>=25 and \<35 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=35 and <45 Years Participants \>=35 and \<45 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=45 and <55 Years Participants \>=45 and \<55 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=55 and <65 Years Participants \>=55 and \<65 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=65 Years Participants \>=65 years years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert
Clinical Efficacy Rate	61.1 Percentage of participants Interval 58.1 to 64.1	—	—	—	—	—	—

SECONDARY outcome

Timeframe: 12 weeks

Population: R ratio analysis population comprised of the participants who calculated R ratio at the start of gabapentin treatment and at the end of monitoring period in the efficacy analysis population.

Response Ratio (R Ratio) was calculated by the following formula, where B represented the frequency of epileptic seizures during 4 weeks before gabapentin treatment, whereas T represented the frequency of epileptic seizures during 4 weeks at the end of observation period of gabapentin treatment: R Ratio= (T-B) / (T+B). R Ratio was within the range of -1 to +1, and a negative value represented a reduction in the frequency of seizure.

Outcome measures

Outcome measures
Measure	Gabapentin 200, 300, 400 mg Tablets n=956 Participants The usual dosage of gabapentin in adults and children aged 13 or older was as follows: oral gabapentin 600 mg, 3 div., was administered on day 1 and an effective dose of 1200 mg, 3 div., was administered on day 2. From day 3 on, oral gabapentin 1200 mg to 1800 mg, 3 div., was administered as the maintenance dose. Subsequently, the maintenance dose was suitably adjusted depending on the symptoms (up to a maximum daily dose of 2400 mg).	Age >=15 and <25 Years Participants \>=15 and \<25 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=25 and <35 Years Participants \>=25 and \<35 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=35 and <45 Years Participants \>=35 and \<45 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=45 and <55 Years Participants \>=45 and \<55 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=55 and <65 Years Participants \>=55 and \<65 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=65 Years Participants \>=65 years years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert
Response Ratio (R Ratio)	-0.410 Ratio Standard Deviation 0.4855	—	—	—	—	—	—

SECONDARY outcome

Timeframe: 12 weeks

Population: Responder rate analysis population comprised of the participants who calculated R ratio at the start of gabapentin treatment and at the end of monitoring period in the efficacy analysis population.

Responder rate, which was defined as the percentage of participants whose R ratio was -0.333 or less, was presented along with the corresponding exact 2-sided 95% CI. R ratio of -0.333 or less corresponded to the decrease of epileptic seizure frequency by 50% or more.

Outcome measures

Outcome measures
Measure	Gabapentin 200, 300, 400 mg Tablets n=956 Participants The usual dosage of gabapentin in adults and children aged 13 or older was as follows: oral gabapentin 600 mg, 3 div., was administered on day 1 and an effective dose of 1200 mg, 3 div., was administered on day 2. From day 3 on, oral gabapentin 1200 mg to 1800 mg, 3 div., was administered as the maintenance dose. Subsequently, the maintenance dose was suitably adjusted depending on the symptoms (up to a maximum daily dose of 2400 mg).	Age >=15 and <25 Years Participants \>=15 and \<25 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=25 and <35 Years Participants \>=25 and \<35 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=35 and <45 Years Participants \>=35 and \<45 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=45 and <55 Years Participants \>=45 and \<55 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=55 and <65 Years Participants \>=55 and \<65 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=65 Years Participants \>=65 years years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert
Responder Rate	55.0 Percentage of participants Interval 51.8 to 58.2	—	—	—	—	—	—

SECONDARY outcome

Timeframe: 12 weeks

Population: The analysis population comprised of the participants whose frequency of epileptic seizures during 4 weeks before gabapentin treatment (represented by B) was at least once within the R ratio analysis population.

Percent reduction from the baseline in epileptic seizure frequency, was calculated by the following formula, where B represented the frequency of epileptic seizures during 4 weeks before gabapentin treatment, whereas T represented the frequency of epileptic seizures during 4 weeks at the end of observation period of gabapentin treatment: Reduction from the baseline in epileptic seizure frequency (%) = \[(T-B)/B\] X 100.

Outcome measures

Outcome measures
Measure	Gabapentin 200, 300, 400 mg Tablets n=950 Participants The usual dosage of gabapentin in adults and children aged 13 or older was as follows: oral gabapentin 600 mg, 3 div., was administered on day 1 and an effective dose of 1200 mg, 3 div., was administered on day 2. From day 3 on, oral gabapentin 1200 mg to 1800 mg, 3 div., was administered as the maintenance dose. Subsequently, the maintenance dose was suitably adjusted depending on the symptoms (up to a maximum daily dose of 2400 mg).	Age >=15 and <25 Years Participants \>=15 and \<25 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=25 and <35 Years Participants \>=25 and \<35 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=35 and <45 Years Participants \>=35 and \<45 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=45 and <55 Years Participants \>=45 and \<55 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=55 and <65 Years Participants \>=55 and \<65 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=65 Years Participants \>=65 years years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert
Percent Reduction From Baseline in Epileptic Seizure Frequency	-34.0 Percentage Standard Deviation 103.70	—	—	—	—	—	—

OTHER_PRE_SPECIFIED outcome

Timeframe: 12 weeks

Population: The safety analysis population comprised of participants who had met the inclusion criteria and had taken gabapentin at least once.

A treatment-related adverse event was any untoward medical occurrence attributed to gabapentin in a participant who received gabapentin. Participants with treatment-related adverse events were counted by age across 7 categories to assess whether the age was a risk factor for the treatment-related adverse events.

Outcome measures

Outcome measures
Measure	Gabapentin 200, 300, 400 mg Tablets n=168 Participants The usual dosage of gabapentin in adults and children aged 13 or older was as follows: oral gabapentin 600 mg, 3 div., was administered on day 1 and an effective dose of 1200 mg, 3 div., was administered on day 2. From day 3 on, oral gabapentin 1200 mg to 1800 mg, 3 div., was administered as the maintenance dose. Subsequently, the maintenance dose was suitably adjusted depending on the symptoms (up to a maximum daily dose of 2400 mg).	Age >=15 and <25 Years n=189 Participants Participants \>=15 and \<25 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=25 and <35 Years n=204 Participants Participants \>=25 and \<35 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=35 and <45 Years n=207 Participants Participants \>=35 and \<45 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=45 and <55 Years n=106 Participants Participants \>=45 and \<55 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=55 and <65 Years n=127 Participants Participants \>=55 and \<65 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=65 Years n=143 Participants Participants \>=65 years years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert
Number of Participants With Treatment-Related Adverse Events by Age Across 7 Categories	27 participants	31 participants	52 participants	58 participants	15 participants	26 participants	22 participants

OTHER_PRE_SPECIFIED outcome

Timeframe: 12 weeks

Population: The safety analysis population comprised of participants who had met the inclusion criteria and had taken gabapentin at least once.

A treatment-related adverse event was any untoward medical occurrence attributed to gabapentin in a participant who received gabapentin. Participants with treatment-related adverse events were counted by the number of concomitant antiepileptic drugs at baseline across 5 categories to assess whether the number of concomitant antiepileptic drugs at baseline was a risk factor for the treatment-related adverse events.

Outcome measures

Outcome measures
Measure	Gabapentin 200, 300, 400 mg Tablets n=67 Participants The usual dosage of gabapentin in adults and children aged 13 or older was as follows: oral gabapentin 600 mg, 3 div., was administered on day 1 and an effective dose of 1200 mg, 3 div., was administered on day 2. From day 3 on, oral gabapentin 1200 mg to 1800 mg, 3 div., was administered as the maintenance dose. Subsequently, the maintenance dose was suitably adjusted depending on the symptoms (up to a maximum daily dose of 2400 mg).	Age >=15 and <25 Years n=453 Participants Participants \>=15 and \<25 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=25 and <35 Years n=373 Participants Participants \>=25 and \<35 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=35 and <45 Years n=202 Participants Participants \>=35 and \<45 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=45 and <55 Years n=49 Participants Participants \>=45 and \<55 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=55 and <65 Years Participants \>=55 and \<65 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=65 Years Participants \>=65 years years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert
Number of Participants With Treatment-Related Adverse Events by Number of Concomitant Antiepileptic Drugs at Baseline	12 participants	70 participants	91 participants	41 participants	17 participants	—	—

OTHER_PRE_SPECIFIED outcome

Timeframe: 12 weeks

Population: The efficacy analysis population comprised of the participants who had at least one post-baseline efficacy evaluation for the clinical efficacy and seizure frequency in the safety analysis population. Participants who had diseases not eligible for the survey were excluded from the efficacy analysis population.

Participants who responded to the treatment with gabapentin were counted by age (\<65 vs. \>=65 years) to assess whether the age was a factor affecting the treatment efficacy.

Outcome measures

Outcome measures
Measure	Gabapentin 200, 300, 400 mg Tablets n=933 Participants The usual dosage of gabapentin in adults and children aged 13 or older was as follows: oral gabapentin 600 mg, 3 div., was administered on day 1 and an effective dose of 1200 mg, 3 div., was administered on day 2. From day 3 on, oral gabapentin 1200 mg to 1800 mg, 3 div., was administered as the maintenance dose. Subsequently, the maintenance dose was suitably adjusted depending on the symptoms (up to a maximum daily dose of 2400 mg).	Age >=15 and <25 Years n=112 Participants Participants \>=15 and \<25 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=25 and <35 Years Participants \>=25 and \<35 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=35 and <45 Years Participants \>=35 and \<45 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=45 and <55 Years Participants \>=45 and \<55 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=55 and <65 Years Participants \>=55 and \<65 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=65 Years Participants \>=65 years years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert
Number of Participants Who Responded to Treatment With Gabapentin by Age (<65 Versus >=65 Years)	545 participants	94 participants	—	—	—	—	—

OTHER_PRE_SPECIFIED outcome

Timeframe: 12 weeks

Population: The efficacy analysis population comprised of the participants who had at least one post-baseline efficacy evaluation for the clinical efficacy and seizure frequency in the safety analysis population. Participants who had diseases not eligible for the survey were excluded from the efficacy analysis population.

Participants who responded to the treatment with gabapentin were counted by age across 7 categories to assess whether the age was a factor affecting the treatment efficacy.

Outcome measures

Outcome measures
Measure	Gabapentin 200, 300, 400 mg Tablets n=161 Participants The usual dosage of gabapentin in adults and children aged 13 or older was as follows: oral gabapentin 600 mg, 3 div., was administered on day 1 and an effective dose of 1200 mg, 3 div., was administered on day 2. From day 3 on, oral gabapentin 1200 mg to 1800 mg, 3 div., was administered as the maintenance dose. Subsequently, the maintenance dose was suitably adjusted depending on the symptoms (up to a maximum daily dose of 2400 mg).	Age >=15 and <25 Years n=182 Participants Participants \>=15 and \<25 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=25 and <35 Years n=188 Participants Participants \>=25 and \<35 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=35 and <45 Years n=196 Participants Participants \>=35 and \<45 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=45 and <55 Years n=96 Participants Participants \>=45 and \<55 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=55 and <65 Years n=110 Participants Participants \>=55 and \<65 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=65 Years n=112 Participants Participants \>=65 years years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert
Number of Participants Who Responded to Treatment With Gabapentin by Age Across 7 Categories	93 participants	91 participants	102 participants	113 participants	64 participants	82 participants	94 participants

OTHER_PRE_SPECIFIED outcome

Timeframe: 12 weeks

Population: The efficacy analysis population comprised of the participants who had at least one post-baseline efficacy evaluation for the clinical efficacy and seizure frequency in the safety analysis population. Participants who who had diseases not eligible for the survey were excluded from the efficacy analysis population.

Participants who responded to the treatment with gabapentin were counted by the severity of partial epileptic seizure (mild, moderate and severe) to assess whether the severity of partial epileptic seizure was a factor affecting the treatment efficacy.

Outcome measures

Outcome measures
Measure	Gabapentin 200, 300, 400 mg Tablets n=220 Participants The usual dosage of gabapentin in adults and children aged 13 or older was as follows: oral gabapentin 600 mg, 3 div., was administered on day 1 and an effective dose of 1200 mg, 3 div., was administered on day 2. From day 3 on, oral gabapentin 1200 mg to 1800 mg, 3 div., was administered as the maintenance dose. Subsequently, the maintenance dose was suitably adjusted depending on the symptoms (up to a maximum daily dose of 2400 mg).	Age >=15 and <25 Years n=595 Participants Participants \>=15 and \<25 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=25 and <35 Years n=220 Participants Participants \>=25 and \<35 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=35 and <45 Years Participants \>=35 and \<45 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=45 and <55 Years Participants \>=45 and \<55 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=55 and <65 Years Participants \>=55 and \<65 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=65 Years Participants \>=65 years years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert
Number of Participants Who Responded to Treatment With Gabapentin by Severity of Partial Epileptic Seizure	150 participants	363 participants	118 participants	—	—	—	—

OTHER_PRE_SPECIFIED outcome

Timeframe: 12 weeks

Population: The efficacy analysis population comprised of the participants who had at least one post-baseline efficacy evaluation for the clinical efficacy and seizure frequency in the safety analysis population. Participants who had diseases not eligible for the survey were excluded from the efficacy analysis population.

Participants who responded to the treatment with gabapentin were counted by the baseline frequency of epileptic seizure (\<=8 vs. \>8 episodes) to assess whether the baseline frequency of epileptic seizure was a factor affecting the treatment efficacy.

Outcome measures

Outcome measures
Measure	Gabapentin 200, 300, 400 mg Tablets n=688 Participants The usual dosage of gabapentin in adults and children aged 13 or older was as follows: oral gabapentin 600 mg, 3 div., was administered on day 1 and an effective dose of 1200 mg, 3 div., was administered on day 2. From day 3 on, oral gabapentin 1200 mg to 1800 mg, 3 div., was administered as the maintenance dose. Subsequently, the maintenance dose was suitably adjusted depending on the symptoms (up to a maximum daily dose of 2400 mg).	Age >=15 and <25 Years n=303 Participants Participants \>=15 and \<25 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=25 and <35 Years n=54 Participants Participants \>=25 and \<35 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=35 and <45 Years Participants \>=35 and \<45 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=45 and <55 Years Participants \>=45 and \<55 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=55 and <65 Years Participants \>=55 and \<65 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=65 Years Participants \>=65 years years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert
Number of Participants Who Responded to Treatment With Gabapentin by Baseline Frequency of Epileptic Seizure	432 participants	166 participants	41 participants	—	—	—	—

OTHER_PRE_SPECIFIED outcome

Timeframe: 12 weeks

Population: The efficacy analysis population comprised of the participants who had at least one post-baseline efficacy evaluation for the clinical efficacy and seizure frequency in the safety analysis population. Participants who had diseases not eligible for the survey were excluded from the efficacy analysis population.

Participants who responded to the treatment with gabapentin were counted by the number of concomitant epileptic drugs at baseline across 5 categories to assess whether the number of concomitant epileptic drugs at baseline was a factor affecting the treatment efficacy.

Outcome measures

Outcome measures
Measure	Gabapentin 200, 300, 400 mg Tablets n=41 Participants The usual dosage of gabapentin in adults and children aged 13 or older was as follows: oral gabapentin 600 mg, 3 div., was administered on day 1 and an effective dose of 1200 mg, 3 div., was administered on day 2. From day 3 on, oral gabapentin 1200 mg to 1800 mg, 3 div., was administered as the maintenance dose. Subsequently, the maintenance dose was suitably adjusted depending on the symptoms (up to a maximum daily dose of 2400 mg).	Age >=15 and <25 Years n=413 Participants Participants \>=15 and \<25 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=25 and <35 Years n=357 Participants Participants \>=25 and \<35 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=35 and <45 Years n=190 Participants Participants \>=35 and \<45 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=45 and <55 Years n=44 Participants Participants \>=45 and \<55 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=55 and <65 Years Participants \>=55 and \<65 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=65 Years Participants \>=65 years years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert
Number of Participants Who Responded to Treatment With Gabapentin by Number of Concomitant Antiepileptic Drugs at Baseline	32 participants	295 participants	190 participants	98 participants	24 participants	—	—

OTHER_PRE_SPECIFIED outcome

Timeframe: 12 weeks

Population: The efficacy analysis population comprised of the participants who had at least one post-baseline efficacy evaluation for the clinical efficacy and seizure frequency in the safety analysis population. Participants who had diseases not eligible for the survey were excluded from the efficacy analysis population.

Participants who responded to the treatment with gabapentin were counted by the baseline creatinine clearance (CLcr) across 6 categories to assess whether the baseline CLcr was a factor affecting the treatment efficacy.

Outcome measures

Outcome measures
Measure	Gabapentin 200, 300, 400 mg Tablets n=439 Participants The usual dosage of gabapentin in adults and children aged 13 or older was as follows: oral gabapentin 600 mg, 3 div., was administered on day 1 and an effective dose of 1200 mg, 3 div., was administered on day 2. From day 3 on, oral gabapentin 1200 mg to 1800 mg, 3 div., was administered as the maintenance dose. Subsequently, the maintenance dose was suitably adjusted depending on the symptoms (up to a maximum daily dose of 2400 mg).	Age >=15 and <25 Years n=36 Participants Participants \>=15 and \<25 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=25 and <35 Years n=4 Participants Participants \>=25 and \<35 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=35 and <45 Years n=1 Participants Participants \>=35 and \<45 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=45 and <55 Years Participants \>=45 and \<55 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=55 and <65 Years n=565 Participants Participants \>=55 and \<65 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=65 Years Participants \>=65 years years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert
Number of Participants Who Responded to Treatment With Gabapentin by Baseline Creatinine Clearance	284 participants	28 participants	4 participants	1 participants	—	322 participants	—

OTHER_PRE_SPECIFIED outcome

Timeframe: 12 weeks

Population: The efficacy analysis population comprised of the participants who had at least one post-baseline efficacy evaluation for the clinical efficacy and seizure frequency in the safety analysis population. Participants who had diseases not eligible for the survey were excluded from the efficacy analysis population.

Participants who responded to the treatment with gabapentin were counted by the presence or absence of non-drug therapy to assess whether the non-drug therapy was a factor affecting the treatment efficacy.

Outcome measures

Outcome measures
Measure	Gabapentin 200, 300, 400 mg Tablets n=45 Participants The usual dosage of gabapentin in adults and children aged 13 or older was as follows: oral gabapentin 600 mg, 3 div., was administered on day 1 and an effective dose of 1200 mg, 3 div., was administered on day 2. From day 3 on, oral gabapentin 1200 mg to 1800 mg, 3 div., was administered as the maintenance dose. Subsequently, the maintenance dose was suitably adjusted depending on the symptoms (up to a maximum daily dose of 2400 mg).	Age >=15 and <25 Years n=1000 Participants Participants \>=15 and \<25 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=25 and <35 Years Participants \>=25 and \<35 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=35 and <45 Years Participants \>=35 and \<45 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=45 and <55 Years Participants \>=45 and \<55 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=55 and <65 Years Participants \>=55 and \<65 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Age >=65 Years Participants \>=65 years years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert
Number of Participants Who Responded to Treatment With Gabapentin by Presence or Absence of Non-Drug Therapy	34 participants	605 participants	—	—	—	—	—

Adverse Events

Gabapentin 200, 300, 400 mg Tablets

Serious events: 29 serious events

Other events: 248 other events

Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure	Gabapentin 200, 300, 400 mg Tablets n=1144 participants at risk The usual dosage of gabapentin in adults and children aged 13 or older was as follows: oral gabapentin 600 mg, 3 div., was administered on day 1 and an effective dose of 1200 mg, 3 div., was administered on day 2. From day 3 on, oral gabapentin 1200 mg to 1800 mg, 3 div., was administered as the maintenance dose. Subsequently, the maintenance dose was suitably adjusted depending on the symptoms (up to a maximum daily dose of 2400 mg).
Blood and lymphatic system disorders Anaemia	0.17% 2/1144 • Number of events 2 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Blood and lymphatic system disorders Pancytopenia	0.09% 1/1144 • Number of events 1 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Infections and infestations Sepsis	0.17% 2/1144 • Number of events 2 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Infections and infestations Pneumonia	0.17% 2/1144 • Number of events 2 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Neoplasm	0.09% 1/1144 • Number of events 1 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Brain neoplasm	0.35% 4/1144 • Number of events 4 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Lung neoplasm malignant	0.09% 1/1144 • Number of events 1 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Nasal sinus cancer	0.09% 1/1144 • Number of events 1 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Metabolism and nutrition disorders Hypophagia	0.09% 1/1144 • Number of events 1 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Psychiatric disorders Restlessness	0.09% 1/1144 • Number of events 1 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Psychiatric disorders Delirium	0.09% 1/1144 • Number of events 1 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Nervous system disorders Epilepsy	0.09% 1/1144 • Number of events 1 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Nervous system disorders Status epilepticus	0.09% 1/1144 • Number of events 1 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Nervous system disorders Altered state of consciousness	0.09% 1/1144 • Number of events 1 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Nervous system disorders Convulsion	0.17% 2/1144 • Number of events 2 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Eye disorders Vogt-Koyanagi-Harada syndrome	0.09% 1/1144 • Number of events 1 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Respiratory, thoracic and mediastinal disorders Dyspnoea	0.09% 1/1144 • Number of events 1 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Respiratory, thoracic and mediastinal disorders Pneumonia aspiration	0.35% 4/1144 • Number of events 4 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Skin and subcutaneous tissue disorders Drug eruption	0.09% 1/1144 • Number of events 1 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Renal and urinary disorders Renal failure acute	0.09% 1/1144 • Number of events 1 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
General disorders Sudden death	0.09% 1/1144 • Number of events 1 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Investigations Haemoglobin decreased	0.09% 1/1144 • Number of events 1 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Injury, poisoning and procedural complications Subdural haematoma	0.09% 1/1144 • Number of events 1 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Injury, poisoning and procedural complications Femoral neck fracture	0.09% 1/1144 • Number of events 1 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.

Other adverse events

Other adverse events
Measure	Gabapentin 200, 300, 400 mg Tablets n=1144 participants at risk The usual dosage of gabapentin in adults and children aged 13 or older was as follows: oral gabapentin 600 mg, 3 div., was administered on day 1 and an effective dose of 1200 mg, 3 div., was administered on day 2. From day 3 on, oral gabapentin 1200 mg to 1800 mg, 3 div., was administered as the maintenance dose. Subsequently, the maintenance dose was suitably adjusted depending on the symptoms (up to a maximum daily dose of 2400 mg).
Psychiatric disorders Decreased activity	0.70% 8/1144 • Number of events 8 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Nervous system disorders Ataxia	0.52% 6/1144 • Number of events 6 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Nervous system disorders Somnolence	12.0% 137/1144 • Number of events 137 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Nervous system disorders Headache	0.52% 6/1144 • Number of events 6 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Nervous system disorders Dizziness	3.5% 40/1144 • Number of events 40 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Hepatobiliary disorders Hepatic function abnormal	0.52% 6/1144 • Number of events 6 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
General disorders Malaise	0.70% 8/1144 • Number of events 8 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Investigations Gamma-glutamyltransferase increased	0.96% 11/1144 • Number of events 11 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Investigations White blood cell count decreased	0.61% 7/1144 • Number of events 7 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Gastrointestinal disorders Nausea	0.52% 6/1144 • Number of events 6 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.
Nervous system disorders Convulsion	1.1% 13/1144 • Number of events 13 • 12 weeks The frequency of adverse events. The same event may appear as both an AE and a SAE. However, what is presented are distinct events. An event may be categorized as serious in one subject and as nonserious in another subject, or one subject may have experienced both a serious and nonserious event during the study.

Additional Information

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Results disclosure agreements

Principal investigator is a sponsor employee Pfizer has the right to review disclosures, requesting a delay of less than 60 days. Investigator will postpone single center publications until after disclosure of pooled data (all sites), less than 12 months from study completion/termination at all participating sites. Investigator may not disclose previously undisclosed confidential information other than study results.
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Restriction type: OTHER