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Evaluation Phenobarbital as Adjunctive Therapy in Participants With Partial Onset Seizures

This study has been completed.
Information provided by (Responsible Party):
West-Ward Pharmaceutical Identifier:
First received: January 20, 2011
Last updated: April 14, 2017
Last verified: April 2017


- to evaluate the efficacy of phenobarbital in reducing seizure frequency.


  • to confirm dose response relationship,
  • to assess the effects on Type I seizures,
  • to assess the safety of phenobarbital
  • to assess the drug tolerability.

Condition Intervention Phase
Drug: Phenobarbital
Drug: Placebo tablet
Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Participant, Care Provider, Investigator, Outcomes Assessor
Primary Purpose: Treatment
Official Title: An International, Double-blind, Parallel-group, Placebo-controlled, Randomized Study: Evaluation of the Efficacy and Safety of Phenobarbital as Adjunctive Therapy in Participants (> or = 17 to 70 Years Old) With Partial Onset Seizures

Resource links provided by NLM:

Further study details as provided by West-Ward Pharmaceutical:

Primary Outcome Measures:
  • Evaluate the efficacy of OD administration of 60 mg and 100 mg phenobarbital in reduction of seizure frequency [ Time Frame: 34 weeks with maximum 22-week exposure to phenobarbital ]
    • determination of partial onset seizure frequency per week over the treatment period
    • comparison of average change in weekly seizure rate from baseline and maintenance period

Secondary Outcome Measures:
  • Confirm the dose response relationship of 60 mg and 100 mg phenobarbital doses [ Time Frame: 34 weeks with a maximum 22-week exposure to phenobarbital ]
  • Assess the effects of phenobarbital on Type I seizures [ Time Frame: 34 weeks with a maximum 22-week exposure to phenobarbital ]
    • seizure freedom rate
    • percent reduction for partial onset seizure
    • responder rate
    • reduction of seizure frequency

  • Assess the safety of phenobarbital [ Time Frame: 34 weeks with a maximum 22-week exposure to phenobarbital ]
    • overview of adverse events in study
    • summary of adverse events in study by severity, seriousness, relationship to study drug, action taken, outcome, treatment
    • summary of serious adverse events

  • Assess the tolerability of phenobarbital [ Time Frame: 34 weeks with maximum 22-week exposure to phenobarbital ]

Enrollment: 314
Study Start Date: November 2010
Study Completion Date: April 2016
Primary Completion Date: January 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Placebo Comparator: Placebo
placebo tablets
Drug: Placebo tablet
Experimental: 60 mg group
Patients titrated to 60mg phenobarbital for maintenance period, then titrated down.
Drug: Phenobarbital
Experimental: 100 mg group
Patients titrated to 100mg phenobarbital maintenance period, then titrated down
Drug: Phenobarbital

Detailed Description:


-to evaluate the efficacy of once daily (OD) administration of 60 mg and 100 mg phenobarbital, in reducing seizure frequency in participants with partial onset seizures (Type I seizures; complex or simple with motor symptoms only) not fully controlled despite treatment with 1 to 3 concomitant anti-epileptic drugs (AEDs) or AEDs with Vagus Nerve Stimulator (VNS)


  • to confirm dose response relationship of 60 and 100 mg phenobarbital doses,
  • to assess the effects of phenobarbital on Type I seizures,
  • to assess the safety of phenobarbital
  • to assess the tolerability of phenobarbital

Ages Eligible for Study:   17 Years to 70 Years   (Child, Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • participants from 17 to 70 years old;
  • history of Type I partial onset seizures (complex or simple with motor symptoms only);
  • participants must have had electroencephalogram (EEG), magnetic resonance imaging (MRI) or computed tomography (CT) with results consistent with diagnosis of partial-onset seizures;
  • participants having at least eight Type I partial onset seizures during 8-week baseline period;
  • participants being uncontrolled while treated by 1 to 3 permitted concomitant anti-epileptic drug (AED) and/or Vagus Nerve Stimulation (VNS);
  • participant has been on a stable dose of their current anti-epileptic treatment regime

Exclusion Criteria:

  • currently taking phenobarbital or primidone;
  • currently taking felbamate or vigabatrin;
  • history of prior allergic reaction to phenobarbital;
  • history of psychogenic seizures;
  • history or presence of status epilepticus;
  • history or presence of seizures occurring only in clusters;
  • participant taking any drug with possible Central Nervous System (CNS) effects except if stable from 1 month prior Visit 1;
  • history of cerebrovascular accident (CVA) or transient ischemic attack (TIA);
  • presence of any sign suggesting rapidly progressing brain disorder or brain tumor;
  • presence of unstable arteriovenous malformations, meningiomas or other benign tumors;
  • history of porphyria;
  • presence of clinically significant findings on physical exam, vital signs, electrocardiogram (ECG) or safety lab assessments, including renal or hepatic insufficiency;
  • history of alcohol or drug abuse within the year prior to screening;
  • participant who is known to be non-compliant;
  • participant who is male or female who refuses to use an acceptable form of contraception;
  • female who is pregnant or lactating or intends to become pregnant;
  • participant who has taken part in any investigational device or product within 2 months prior to the screening visit
  Contacts and Locations
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Please refer to this study by its identifier: NCT01284556

United States, Kentucky
Bluegrass Epilepsy Research
Lexington, Kentucky, United States, 40504
United States, Oklahoma
Lynn Health Science Institute
Oklahoma City, Oklahoma, United States, 73112
Puerto Rico
Hospital Del Maestro
Hato Rey, Puerto Rico, 00918
Centro Neurodiagnostico
Rio Piedras, Puerto Rico, 00924
Sponsors and Collaborators
West-Ward Pharmaceutical
  More Information

Responsible Party: West-Ward Pharmaceutical Identifier: NCT01284556     History of Changes
Other Study ID Numbers: AGG-901
2010-020871-22 ( EudraCT Number )
Study First Received: January 20, 2011
Last Updated: April 14, 2017

Keywords provided by West-Ward Pharmaceutical:
partial onset seizures

Additional relevant MeSH terms:
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Neurologic Manifestations
Signs and Symptoms
Hypnotics and Sedatives
Central Nervous System Depressants
Physiological Effects of Drugs
Excitatory Amino Acid Antagonists
Excitatory Amino Acid Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
GABA Modulators
GABA Agents
Cytochrome P-450 CYP2B6 Inducers
Cytochrome P-450 Enzyme Inducers
Cytochrome P-450 CYP3A Inducers processed this record on April 26, 2017