Drug Use Investigation Of Gabapentin

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
Pfizer
ClinicalTrials.gov Identifier:
NCT00567268
First received: November 16, 2007
Last updated: April 23, 2015
Last verified: April 2015
  Purpose

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 Intervention Phase
Epilepsies, Partial
Drug: Gabapentin
Phase 4

Study Type: Observational
Study Design: Observational Model: Case-Only
Time Perspective: Prospective
Official Title: Drug Use Investigation Of Gabapen

Resource links provided by NLM:


Further study details as provided by Pfizer:

Primary Outcome Measures:
  • Number of Participants With Treatment-Related Adverse Events Unexpected From Japanese Package Insert [ Time Frame: 12 weeks ] [ Designated as safety issue: Yes ]
    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.).

  • Number of Participants With Treatment-Related Adverse Events [ Time Frame: 12 weeks ] [ Designated as safety issue: Yes ]
    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.).

  • Clinical Efficacy Rate [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]
    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:
  • Response Ratio (R Ratio) [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]
    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.

  • Responder Rate [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]
    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.

  • Percent Reduction From Baseline in Epileptic Seizure Frequency [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]
    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:
  • Number of Participants With Treatment-Related Adverse Events by Age Across 7 Categories [ Time Frame: 12 weeks ] [ Designated as safety issue: Yes ]
    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.

  • Number of Participants With Treatment-Related Adverse Events by Number of Concomitant Antiepileptic Drugs at Baseline [ Time Frame: 12 weeks ] [ Designated as safety issue: Yes ]
    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.

  • Number of Participants Who Responded to Treatment With Gabapentin by Age (<65 Versus >=65 Years) [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]
    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.

  • Number of Participants Who Responded to Treatment With Gabapentin by Age Across 7 Categories [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]
    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.

  • Number of Participants Who Responded to Treatment With Gabapentin by Severity of Partial Epileptic Seizure [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]
    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.

  • Number of Participants Who Responded to Treatment With Gabapentin by Baseline Frequency of Epileptic Seizure [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]
    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.

  • Number of Participants Who Responded to Treatment With Gabapentin by Number of Concomitant Antiepileptic Drugs at Baseline [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]
    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.

  • Number of Participants Who Responded to Treatment With Gabapentin by Baseline Creatinine Clearance [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]
    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.

  • Number of Participants Who Responded to Treatment With Gabapentin by Presence or Absence of Non-Drug Therapy [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]
    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.


Enrollment: 1273
Study Start Date: August 2007
Study Completion Date: May 2014
Primary Completion Date: May 2014 (Final data collection date for primary outcome measure)
Groups/Cohorts Assigned Interventions
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.


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.

  Eligibility

Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population

The patients whom an investigator involving A9451163 prescribes the Gabapentin

Criteria

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
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00567268

Sponsors and Collaborators
Pfizer
Investigators
Study Director: Pfizer CT.gov Call Center Pfizer
  More Information

Additional Information:
No publications provided

Responsible Party: Pfizer
ClinicalTrials.gov Identifier: NCT00567268     History of Changes
Other Study ID Numbers: A9451163
Study First Received: November 16, 2007
Results First Received: April 23, 2015
Last Updated: April 23, 2015
Health Authority: Japan: Institutional Review Board

Keywords provided by Pfizer:
Post-Marketing surveillance

Additional relevant MeSH terms:
Epilepsies, Partial
Brain Diseases
Central Nervous System Diseases
Epilepsy
Nervous System Diseases
Gabapentin
Analgesics
Anti-Anxiety Agents
Anti-Dyskinesia Agents
Anticonvulsants
Antimanic Agents
Antiparkinson Agents
Calcium Channel Blockers
Cardiovascular Agents
Central Nervous System Agents
Central Nervous System Depressants
Excitatory Amino Acid Agents
Excitatory Amino Acid Antagonists
Membrane Transport Modulators
Molecular Mechanisms of Pharmacological Action
Neurotransmitter Agents
Peripheral Nervous System Agents
Pharmacologic Actions
Physiological Effects of Drugs
Psychotropic Drugs
Sensory System Agents
Therapeutic Uses
Tranquilizing Agents

ClinicalTrials.gov processed this record on May 21, 2015