Drug Use Investigation Of Gabapentin

Study Overview
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Brief Summary
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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.

Detailed Description
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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.

Official Title
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Drug Use Investigation Of Gabapen

Conditions
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Epilepsies, Partial

Intervention / Treatment
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* Drug: Gabapentin


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients need to be taking Gabapentin in order to be enrolled in the surveillance Exclusion Criteria: Patients not taking Gabapentin
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Gabapentin<br>Patients taking Gabapentin | Drug: Gabapentin<br>* 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.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Participants With Treatment-Related Adverse Events Unexpected From Japanese Package Insert | 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.). | 12 weeks | 
| Number of Participants With Treatment-Related Adverse Events | 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.). | 12 weeks | 
| Clinical Efficacy Rate | 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. | 12 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Response Ratio (R Ratio) | 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. | 12 weeks | 
| Responder Rate | 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. | 12 weeks | 
| Percent Reduction From Baseline in Epileptic Seizure Frequency | 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. | 12 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Post-Marketing surveillance