Drug Use Investigation Of Gabapentin

• Sponsor: Pfizer's Upjohn has merged with Mylan to form Viatris Inc. (Industry)
• Overall Status: Completed
• CT.gov ID: NCT00567268
• Collaborator: (none)
• Enrollment: 1,273
• Duration (Months): 81

Study Details

Study Description

Brief Summary

The objective of the this surveillance is to collect information about 1)adverse drug reactions not expected from the LPD (unknown adverse drug reactions), 2) the incidence of adverse drug reactions in this surveillance, and 3) factors considered to affect the safety and/or efficacy of this drug.

Condition or Disease	Intervention/Treatment	Phase
Epilepsies, Partial	Drug: Gabapentin

Detailed Description

All the patients whom an investigator prescribes the first Gabapentin should be registered consecutively until the number of subjects reaches target number in order to extract patients enrolled into the investigation at random.

Study Design

• Study Type: Observational
• Actual Enrollment: 1273 participants
• Observational Model: Case-Only
• Time Perspective: Prospective
• Official Title: Drug Use Investigation Of Gabapen
• Study Start Date: Aug 1, 2007
• Actual Primary Completion Date: May 1, 2014
• Actual Study Completion Date: May 1, 2014

Arms and Interventions

Arm

Intervention/Treatment

Gabapentin Patients taking Gabapentin

Drug: Gabapentin; GABAPEN Tablets 200mg, GABAPEN Tablets 300mg, GABAPEN Tablets 400mg. GABAPEN is Brand name in Japan. Dosage, frequency: According to Japanese LPD, "Normally, oral gabapentin 600 mg, 3 div., should be given on the first day of administration and an effective dose of 1200mg, 3 div, should be given on day 2. From day 3 on, adults should be maintained on oral gabapentin 1200 mg to 1800 mg, 3 div. Subsequently, the maintenance dose should be suitably adjusted depending on the symptoms (up to a maximum daily dose of 2400 mg)". Duration: According to the protocol of A9451163, the duration of the investigation for findings regarding safety and efficacy of a patient is from the first drug administration to the 12 weeks after the first administration.

Outcome Measures

Primary Outcome Measures

1. Number of Participants With Treatment-Related Adverse Events Unexpected From Japanese Package Insert [12 weeks]

   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.).

2. Number of Participants With Treatment-Related Adverse Events [12 weeks]

   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.).

3. Clinical Efficacy Rate [12 weeks]

   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.

Secondary Outcome Measures

1. Response Ratio (R Ratio) [12 weeks]

   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.

2. Responder Rate [12 weeks]

   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.

3. Percent Reduction From Baseline in Epileptic Seizure Frequency [12 weeks]

   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.

Other Outcome Measures

1. Number of Participants With Treatment-Related Adverse Events by Age Across 7 Categories [12 weeks]

   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.

2. Number of Participants With Treatment-Related Adverse Events by Number of Concomitant Antiepileptic Drugs at Baseline [12 weeks]

   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.

3. Number of Participants Who Responded to Treatment With Gabapentin by Age (<65 Versus >=65 Years) [12 weeks]

   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.

4. Number of Participants Who Responded to Treatment With Gabapentin by Age Across 7 Categories [12 weeks]

   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.

5. Number of Participants Who Responded to Treatment With Gabapentin by Severity of Partial Epileptic Seizure [12 weeks]

   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.

6. Number of Participants Who Responded to Treatment With Gabapentin by Baseline Frequency of Epileptic Seizure [12 weeks]

   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.

7. Number of Participants Who Responded to Treatment With Gabapentin by Number of Concomitant Antiepileptic Drugs at Baseline [12 weeks]

   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.

8. Number of Participants Who Responded to Treatment With Gabapentin by Baseline Creatinine Clearance [12 weeks]

   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.

9. Number of Participants Who Responded to Treatment With Gabapentin by Presence or Absence of Non-Drug Therapy [12 weeks]

   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.

Eligibility Criteria

Criteria

• Ages Eligible for Study: N/A and Older
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: No

Inclusion Criteria:

Patients need to be taking Gabapentin in order to be enrolled in the surveillance

Exclusion Criteria:

Patients not taking Gabapentin

Contacts and Locations

Locations

No locations specified.

Sponsors and Collaborators

• Pfizer's Upjohn has merged with Mylan to form Viatris Inc.

Investigators

• Study Director: Pfizer CT.gov Call Center, Pfizer

Study Documents (Full-Text)

None provided.

More Information

Additional Information:

• To obtain contact information for a study center near you, click here.

Publications

None provided.

• Responsible Party: Pfizer's Upjohn has merged with Mylan to form Viatris Inc.
• ClinicalTrials.gov Identifier: NCT00567268
• Other Study ID Numbers: A9451163
• First Posted: Dec 4, 2007
• Last Update Posted: Feb 3, 2021
• Last Verified: Sep 1, 2015

• Keywords provided by Pfizer's Upjohn has merged with Mylan to form Viatris Inc.: Post-Marketing surveillance
• Additional relevant MeSH terms: Epilepsies, Partial; Gabapentin

Study Results

Participant Flow

Arm/Group Title	Gabapentin 200, 300, 400 mg Tablets
Arm/Group Description	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).
Period Title: Overall Study
STARTED	1194
COMPLETED	1144
NOT COMPLETED	50

Baseline Characteristics

Arm/Group Title	Gabapentin 200, 300, 400 mg Tablets
Arm/Group Description	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 Participants	1144
Age, Customized (participants) [Number]
<65 years	1001 87.5%
>=65 years	143 12.5%
Sex: Female, Male (Count of Participants)
Female	542 47.4%
Male	602 52.6%

Outcome Measures

1. Primary Outcome

Title	Number of Participants With Treatment-Related Adverse Events Unexpected From Japanese Package Insert
Description	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.).
Time Frame	12 weeks

Outcome Measure Data

Analysis Population Description

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

Arm/Group Title	Gabapentin 200, 300, 400 mg Tablets
Arm/Group Description	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).
Measure Participants	1144
Number [participants]	27 2.4%

2. Primary Outcome

Title	Number of Participants With Treatment-Related Adverse Events
Description	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.).
Time Frame	12 weeks

Outcome Measure Data

Analysis Population Description

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

Arm/Group Title	Gabapentin 200, 300, 400 mg Tablets
Arm/Group Description	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).
Measure Participants	1144
Number [participants]	231 20.2%

3. Primary Outcome

Title	Clinical Efficacy Rate
Description	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.
Time Frame	12 weeks

Outcome Measure Data

Analysis Population Description

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.

Arm/Group Title	Gabapentin 200, 300, 400 mg Tablets
Arm/Group Description	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).
Measure Participants	1045
Number (95% Confidence Interval) [Percentage of participants]	61.1 5.3%

4. Secondary Outcome

Title	Response Ratio (R Ratio)
Description	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.
Time Frame	12 weeks

Outcome Measure Data

Analysis Population Description

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.

Arm/Group Title	Gabapentin 200, 300, 400 mg Tablets
Arm/Group Description	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).
Measure Participants	956
Mean (Standard Deviation) [Ratio]	-0.410 (0.4855)

5. Secondary Outcome

Title	Responder Rate
Description	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.
Time Frame	12 weeks

Outcome Measure Data

Analysis Population Description

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.

Arm/Group Title	Gabapentin 200, 300, 400 mg Tablets
Arm/Group Description	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).
Measure Participants	956
Number (95% Confidence Interval) [Percentage of participants]	55.0 4.8%

6. Secondary Outcome

Title	Percent Reduction From Baseline in Epileptic Seizure Frequency
Description	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.
Time Frame	12 weeks

Outcome Measure Data

Analysis Population Description

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.

Arm/Group Title	Gabapentin 200, 300, 400 mg Tablets
Arm/Group Description	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).
Measure Participants	950
Mean (Standard Deviation) [Percentage]	-34.0 (103.70)

7. Other Pre-specified Outcome

Title	Number of Participants With Treatment-Related Adverse Events by Age Across 7 Categories
Description	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.
Time Frame	12 weeks

Outcome Measure Data

Analysis Population Description

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

Arm/Group Title	Age <15 Years	Age >=15 and <25 Years	Age >=25 and <35 Years	Age >=35 and <45 Years	Age >=45 and <55 Years	Age >=55 and <65 Years	Age >=65 Years
Arm/Group Description	Participants <15 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Participants >=15 and <25 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Participants >=25 and <35 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Participants >=35 and <45 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Participants >=45 and <55 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Participants >=55 and <65 years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert	Participants >=65 years years of age taking gabapentin oral tablets 200, 300, or 400 mg according to the Japanese package insert
Measure Participants	168	189	204	207	106	127	143
Number [participants]	27 2.4%	31 NaN	52 NaN	58 NaN	15 NaN	26 NaN	22 NaN

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	Gabapentin 200, 300, 400 mg Tablets, Age >=15 and <25 Years, Age >=25 and <35 Years, Age >=35 and <45 Years, Age >=45 and <55 Years, Age >=55 and <65 Years, Age >=65 Years
	Comments	The risk factor tested was "age". The null hypothesis was that there was no association between the age and the number of responders to the treatment with gabapentin.
	Type of Statistical Test	Superiority or Other (legacy)
	Comments
Statistical Test of Hypothesis	p-Value	=0.004
	Comments
	Method	Fisher Exact
	Comments

8. Other Pre-specified Outcome

Title	Number of Participants With Treatment-Related Adverse Events by Number of Concomitant Antiepileptic Drugs at Baseline
Description	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.
Time Frame	12 weeks

Outcome Measure Data

Analysis Population Description

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

Arm/Group Title	No Concomitant Antiepileptic Drug	One Concomitant Antiepileptic Drug	Two Concomitant Antiepileptic Drugs	Three Concomitant Antiepileptic Drugs	Four or More Concomitant Antiepileptic Drugs
Arm/Group Description	Participants taking no concomitant antiepileptic drug at baseline	Participants taking one concomitant antiepileptic drug at baseline	Participants taking two concomitant antiepileptic drugs at baseline	Participants taking three concomitant antiepileptic drugs at baseline	Participants taking four or more concomitant antiepileptic drugs at baseline
Measure Participants	67	453	373	202	49
Number [participants]	12 1%	70 NaN	91 NaN	41 NaN	17 NaN

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	Gabapentin 200, 300, 400 mg Tablets, Age >=15 and <25 Years, Age >=25 and <35 Years, Age >=35 and <45 Years, Age >=45 and <55 Years
	Comments	The risk factor tested was "number of concomitant antiepileptic drugs at baseline". The null hypothesis was that there was no linear trend in the number of responders to the treatment with gabapentin across increasing levels of the number of concomitant antiepileptic drugs at baseline.
	Type of Statistical Test	Superiority or Other (legacy)
	Comments
Statistical Test of Hypothesis	p-Value	=0.003
	Comments
	Method	Fisher Exact
	Comments

Statistical Analysis 2

Statistical Analysis Overview	Comparison Group Selection	Gabapentin 200, 300, 400 mg Tablets, Age >=15 and <25 Years, Age >=25 and <35 Years, Age >=35 and <45 Years, Age >=45 and <55 Years
	Comments	The risk factor tested was "number of concomitant antiepileptic drugs at baseline". The null hypothesis was that there was no linear trend in the number of responders to the treatment with gabapentin across increasing levels of the number of concomitant antiepileptic drugs at baseline.
	Type of Statistical Test	Superiority or Other (legacy)
	Comments
Statistical Test of Hypothesis	p-Value	=0.003
	Comments
	Method	Cochran-Armitage
	Comments

9. Other Pre-specified Outcome

Title	Number of Participants Who Responded to Treatment With Gabapentin by Age (<65 Versus >=65 Years)
Description	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.
Time Frame	12 weeks

Outcome Measure Data

Analysis Population Description

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.

Arm/Group Title	Age <65 Years	Age >=65 Years
Arm/Group Description	Participants <65 years of age who responded to the treatment with gabapentin	Participants >=65 years of age who responded to the treatment with gabapentin
Measure Participants	933	112
Number [participants]	545 47.6%	94 NaN

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	Gabapentin 200, 300, 400 mg Tablets, Age >=15 and <25 Years
	Comments	The factor tested was "age". The null hypothesis was that there was no difference between <65 years and >=65 years in the number of participants who responded to the treatment with gabapentin.
	Type of Statistical Test	Superiority or Other (legacy)
	Comments
Statistical Test of Hypothesis	p-Value	<0.001
	Comments
	Method	Chi-squared
	Comments

10. Other Pre-specified Outcome

Title	Number of Participants Who Responded to Treatment With Gabapentin by Age Across 7 Categories
Description	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.
Time Frame	12 weeks

Outcome Measure Data

Analysis Population Description

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.

Arm/Group Title	Age <15 Years	Age >=15 and <25 Years	Age >=25 and <35 Years	Age >=35 and <45 Years	Age >=45 and <55 Years	Age >=55 and <65 Years	Age >=65 Years
Arm/Group Description	Participants <15 years of age who responded to the treatment with gabapentin	Participants >=15 and <25 years of age who responded to the treatment with gabapentin	Participants >=25 and <35 years of age who responded to the treatment with gabapentin	Participants >=35 and <45 years of age who responded to the treatment with gabapentin	Participants >=45 and <55 years of age who responded to the treatment with gabapentin	Participants >=55 and <65 years of age who responded to the treatment with gabapentin	Participants >=65 years of age who responded to the treatment with gabapentin
Measure Participants	161	182	188	196	96	110	112
Number [participants]	93 8.1%	91 NaN	102 NaN	113 NaN	64 NaN	82 NaN	94 NaN

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	Gabapentin 200, 300, 400 mg Tablets, Age >=15 and <25 Years, Age >=25 and <35 Years, Age >=35 and <45 Years, Age >=45 and <55 Years, Age >=55 and <65 Years, Age >=65 Years
	Comments	The factor tested was "age". The null hypothesis was that there was no association between the age and the number of participants who responded to the treatment with gabapentin.
	Type of Statistical Test	Superiority or Other (legacy)
	Comments
Statistical Test of Hypothesis	p-Value	<0.001
	Comments
	Method	Chi-squared
	Comments

Statistical Analysis 2

Statistical Analysis Overview	Comparison Group Selection	Gabapentin 200, 300, 400 mg Tablets, Age >=15 and <25 Years, Age >=25 and <35 Years, Age >=35 and <45 Years, Age >=45 and <55 Years, Age >=55 and <65 Years, Age >=65 Years
	Comments	The factor tested was "age". The null hypothesis was that there was no linear trend in the number of responders to the treatment with gabapentin across increasing levels of age categories.
	Type of Statistical Test	Superiority or Other (legacy)
	Comments
Statistical Test of Hypothesis	p-Value	<0.001
	Comments
	Method	Cochran-Armitage
	Comments

11. Other Pre-specified Outcome

Title	Number of Participants Who Responded to Treatment With Gabapentin by Severity of Partial Epileptic Seizure
Description	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.
Time Frame	12 weeks

Outcome Measure Data

Analysis Population Description

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.

Arm/Group Title	Mild	Moderate	Severe
Arm/Group Description	Participants with mild epilepsy who responded to the treatment with gabapentin	Participants with moderate epilepsy who responded to the treatment with gabapentin	Participants with severe epilepsy who responded to the treatment with gabapentin
Measure Participants	220	595	220
Number [participants]	150 13.1%	363 NaN	118 NaN

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	Gabapentin 200, 300, 400 mg Tablets, Age >=15 and <25 Years, Age >=25 and <35 Years
	Comments	The factor tested was "severity of partial epileptic seizure ". The null hypothesis was that there was no association between the degree of severity of partial epileptic seizure (mild, moderate, and severe) and the number of participants who responded to the treatment with gabapentin.
	Type of Statistical Test	Superiority or Other (legacy)
	Comments
Statistical Test of Hypothesis	p-Value	=0.008
	Comments
	Method	Chi-squared
	Comments

Statistical Analysis 2

Statistical Analysis Overview	Comparison Group Selection	Gabapentin 200, 300, 400 mg Tablets, Age >=15 and <25 Years, Age >=25 and <35 Years
	Comments	The factor tested was "severity of partial epileptic seizure". The null hypothesis was that there was no linear trend in the number of responders to the treatment with gabapentin across the degree of severity of partial epileptic seizure (mild, moderate, and severe).
	Type of Statistical Test	Superiority or Other (legacy)
	Comments
Statistical Test of Hypothesis	p-Value	=0.002
	Comments
	Method	Cochran-Armitage
	Comments

12. Other Pre-specified Outcome

Title	Number of Participants Who Responded to Treatment With Gabapentin by Baseline Frequency of Epileptic Seizure
Description	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.
Time Frame	12 weeks

Outcome Measure Data

Analysis Population Description

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.

Arm/Group Title	<=8 Episodes	>8 Episodes	Unknown
Arm/Group Description	Participants with baseline episodes of epileptic seizure below 8 who responded to the treatment with gabapentin	Participants with baseline episodes of epileptic seizure more than 8 who responded to the treatment with gabapentin	Participants with unknown frequency of baseline episodes who responded to the treatment with gabapentin
Measure Participants	688	303	54
Number [participants]	432 37.8%	166 NaN	41 NaN

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	Gabapentin 200, 300, 400 mg Tablets, Age >=15 and <25 Years
	Comments	The factor tested was "baseline frequency of epileptic seizure". The null hypothesis was that there was no difference between the baseline frequency of epileptic seizure and the number of participants who responded to the treatment with gabapentin.
	Type of Statistical Test	Superiority or Other (legacy)
	Comments
Statistical Test of Hypothesis	p-Value	=0.018
	Comments
	Method	Chi-squared
	Comments

13. Other Pre-specified Outcome

Title	Number of Participants Who Responded to Treatment With Gabapentin by Number of Concomitant Antiepileptic Drugs at Baseline
Description	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.
Time Frame	12 weeks

Outcome Measure Data

Analysis Population Description

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.

Arm/Group Title	No Concomitant Antiepileptic Drug	One Concomitant Antiepileptic Drug	Two Concomitant Antiepileptic Drugs	Three Concomitant Antiepileptic Drugs	Four or More Concomitant Antiepileptic Drugs
Arm/Group Description	Participants taking no concomitant antiepileptic drug at baseline	Participants taking one concomitant antiepileptic drug at baseline	Participants taking two concomitant antiepileptic drugs at baseline	Participants taking three concomitant antiepileptic drugs at baseline	Participants taking four or more concomitant antiepileptic drugs at baseline
Measure Participants	41	413	357	190	44
Number [participants]	32 2.8%	295 NaN	190 NaN	98 NaN	24 NaN

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	Gabapentin 200, 300, 400 mg Tablets, Age >=15 and <25 Years, Age >=25 and <35 Years, Age >=35 and <45 Years, Age >=45 and <55 Years
	Comments	The factor tested was "number of concomitant antiepileptic drugs at baseline". The null hypothesis was that there was no association between the number of concomitant antiepileptic drugs at baseline and the number of participants who responded to the treatment with gabapentin.
	Type of Statistical Test	Superiority or Other (legacy)
	Comments
Statistical Test of Hypothesis	p-Value	<0.001
	Comments
	Method	Chi-squared
	Comments

Statistical Analysis 2

Statistical Analysis Overview	Comparison Group Selection	Gabapentin 200, 300, 400 mg Tablets, Age >=15 and <25 Years, Age >=25 and <35 Years, Age >=35 and <45 Years, Age >=45 and <55 Years
	Comments	The factor tested was "number of concomitant antiepileptic drugs at baseline". The null hypothesis was that there was no linear trend in the number of responders to the treatment with gabapentin across increasing levels of the number of concomitant antiepileptic drugs at baseline.
	Type of Statistical Test	Superiority or Other (legacy)
	Comments
Statistical Test of Hypothesis	p-Value	<0.001
	Comments
	Method	Cochran-Armitage
	Comments

14. Other Pre-specified Outcome

Title	Number of Participants Who Responded to Treatment With Gabapentin by Baseline Creatinine Clearance
Description	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.
Time Frame	12 weeks

Outcome Measure Data

Analysis Population Description

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.

Arm/Group Title	CLcr >=60 mL/Min	CLcr >=30 and <60 mL/Min	CLcr >=15 and <30 mL/Min	CLcr >=5 and <15 mL/Min	CLcr <5 mL/Min	Unkown
Arm/Group Description	Participants with baseline creatinine clearance >=60 mL/min	Participants with baseline creatinine clearance >=30 and <60 mL/min	Participants with baseline creatinine clearance >=15 and <30 mL/min	Participants with baseline creatinine clearance >=5 and <15 mL/min	Participants with baseline creatinine clearance <5 mL/min	Participants with unkown baseline creatinine clearance
Measure Participants	439	36	4	1	0	565
Number [participants]	284 24.8%	28 NaN	4 NaN	1 NaN	322 NaN

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	Gabapentin 200, 300, 400 mg Tablets, Age >=15 and <25 Years, Age >=25 and <35 Years, Age >=35 and <45 Years, Age >=45 and <55 Years
	Comments	The factor tested was "baseline creatinine clearance". The null hypothesis was that there was no linear trend in the number of responders to the treatment with gabapentin across increasing levels of the baseline creatinine clearance.
	Type of Statistical Test	Superiority or Other (legacy)
	Comments
Statistical Test of Hypothesis	p-Value	=0.025
	Comments
	Method	Cochran-Armitage
	Comments

15. Other Pre-specified Outcome

Title	Number of Participants Who Responded to Treatment With Gabapentin by Presence or Absence of Non-Drug Therapy
Description	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.
Time Frame	12 weeks

Outcome Measure Data

Analysis Population Description

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.

Arm/Group Title	Presence of Non-Drug Therapy	Absence of Non-Drug Therapy
Arm/Group Description	Participants with non-drug therapy who responded to treatment with gabapentin	Participants without non-drug therapy who responded to treatment with gabapentin
Measure Participants	45	1000
Number [participants]	34 3%	605 NaN

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	Gabapentin 200, 300, 400 mg Tablets, Age >=15 and <25 Years
	Comments	The factor tested was "non-drug therapy". The null hypothesis was that there was no difference between the non-drug therapy and the number of participants who responded to the treatment with gabapentin.
	Type of Statistical Test	Superiority or Other (legacy)
	Comments
Statistical Test of Hypothesis	p-Value	=0.043
	Comments
	Method	Chi-squared
	Comments

Adverse Events

Time Frame	12 weeks
Adverse Event Reporting Description	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.
Arm/Group Title	Gabapentin 200, 300, 400 mg Tablets
Arm/Group Description	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).
All Cause Mortality
	Gabapentin 200, 300, 400 mg Tablets
	Affected / at Risk (%)	# Events
Total	/ (NaN)
Serious Adverse Events
	Gabapentin 200, 300, 400 mg Tablets
	Affected / at Risk (%)	# Events
Total	29/1144 (2.5%)
Blood and lymphatic system disorders
Anaemia	2/1144 (0.2%)	2
Pancytopenia	1/1144 (0.1%)	1
Eye disorders
Vogt-Koyanagi-Harada syndrome	1/1144 (0.1%)	1
General disorders
Sudden death	1/1144 (0.1%)	1
Infections and infestations
Sepsis	2/1144 (0.2%)	2
Pneumonia	2/1144 (0.2%)	2
Injury, poisoning and procedural complications
Subdural haematoma	1/1144 (0.1%)	1
Femoral neck fracture	1/1144 (0.1%)	1
Investigations
Haemoglobin decreased	1/1144 (0.1%)	1
Metabolism and nutrition disorders
Hypophagia	1/1144 (0.1%)	1
Neoplasms benign, malignant and unspecified (incl cysts and polyps)
Neoplasm	1/1144 (0.1%)	1
Brain neoplasm	4/1144 (0.3%)	4
Lung neoplasm malignant	1/1144 (0.1%)	1
Nasal sinus cancer	1/1144 (0.1%)	1
Nervous system disorders
Epilepsy	1/1144 (0.1%)	1
Status epilepticus	1/1144 (0.1%)	1
Altered state of consciousness	1/1144 (0.1%)	1
Convulsion	2/1144 (0.2%)	2
Psychiatric disorders
Restlessness	1/1144 (0.1%)	1
Delirium	1/1144 (0.1%)	1
Renal and urinary disorders
Renal failure acute	1/1144 (0.1%)	1
Respiratory, thoracic and mediastinal disorders
Dyspnoea	1/1144 (0.1%)	1
Pneumonia aspiration	4/1144 (0.3%)	4
Skin and subcutaneous tissue disorders
Drug eruption	1/1144 (0.1%)	1
Other (Not Including Serious) Adverse Events
	Gabapentin 200, 300, 400 mg Tablets
	Affected / at Risk (%)	# Events
Total	248/1144 (21.7%)
Gastrointestinal disorders
Nausea	6/1144 (0.5%)	6
General disorders
Malaise	8/1144 (0.7%)	8
Hepatobiliary disorders
Hepatic function abnormal	6/1144 (0.5%)	6
Investigations
Gamma-glutamyltransferase increased	11/1144 (1%)	11
White blood cell count decreased	7/1144 (0.6%)	7
Nervous system disorders
Ataxia	6/1144 (0.5%)	6
Somnolence	137/1144 (12%)	137
Headache	6/1144 (0.5%)	6
Dizziness	40/1144 (3.5%)	40
Convulsion	13/1144 (1.1%)	13
Psychiatric disorders
Decreased activity	8/1144 (0.7%)	8

Limitations/Caveats

[Not Specified]

More Information

Certain Agreements

Principal Investigators are NOT employed by the organization sponsoring the study.

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.