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Safety and Efficacy of Gabapentin in Postherpetic Neuralgia

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00335933
Recruitment Status : Completed
First Posted : June 12, 2006
Last Update Posted : August 2, 2007
Information provided by:

Brief Summary:
Gabapentin and pregabalin are treatments for some types of neuropathic pain, including postherpetic neuralgia (PHN). However, these treatments usually need to be taken 3 times a day for effective pain control. The purpose of this study is to determine whether a new gabapentin tablet, which only needs to be taken once or twice a day, is safe and effective for the treatment of postherpetic neuralgia.

Condition or disease Intervention/treatment Phase
Neuralgia, Postherpetic Drug: Gabapentin extended-release tablets Phase 3

Detailed Description:

The primary study objective is to assess the relative efficacy of G-ER dosed once daily (1800 mg following the evening meal) or twice daily (600 mg AM/1200 mg PM), versus placebo in reducing the mean daily pain score from the baseline week to the end of the efficacy treatment period (Treatment Week 10) in patients with PHN.

Secondary efficacy measures will include changes from baseline in mean weekly sleep interference scores, Short-Form McGill Pain Questionnaire (SF-MPQ), the Neuropathic Pain Scale (NPS), Brief Pain Inventory (BPI), Patient Global Impression of Change (PGIC), and Investigator-Rated Clinical Global Impression of Change (CGIC).

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 378 participants
Allocation: Randomized
Intervention Model: Factorial Assignment
Masking: Double
Primary Purpose: Treatment
Official Title: A Phase 3 Multicenter, Randomized, Double-Blind, Placebo-Controlled Study of the Safety and Efficacy of Gabapentin Extended Release (G-ER) Tablets in the Treatment of Patients With Postherpetic Neuralgia
Study Start Date : May 2006
Actual Study Completion Date : July 2007

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Shingles

Primary Outcome Measures :
  1. The primary study objective is to assess the relative efficacy of G-ER versus placebo in reducing the average daily pain score from the baseline week to the final week of the efficacy treatment period (Treatment Week 10) in patients with PHN
  2. Daily pain scores will be measured using an electronic diary.

Secondary Outcome Measures :
  1. Secondary objectives include assessment of changes from baseline in average daily sleep interference scores.

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  1. Men or women 18 years or older who have experienced pain for at least 3 months after the healing of a herpes zoster skin rash (typically about 4 months after the rash first appears).
  2. Patient has pain intensity score of at least 4 on the 11-point Likert numerical rating scale at screening. Potential patients should not be informed of the pain intensity eligibility criterion prior to screening or randomization.
  3. Patients of childbearing potential must have a negative urine pregnancy test at screening/randomization, and must use medically acceptable methods of birth control. Acceptable methods of birth control include oral or transdermal contraceptives, condom, spermicidal foam, intrauterine device (IUD), progestin implant or injection, abstinence, vaginal ring, or sterilization of partner. The reason for non-childbearing potential, such as bilateral tubal ligation, bilateral oophorectomy, hysterectomy, or postmenopausal for ≥ 1 year, must be specified in the patient's case report form (CRF).
  4. Patient has a mean baseline week pain intensity score of at least 4 on the 11-point Likert scale at the end of a 1-week pre-treatment period and has completed at least 4 days of daily pain diary entries during the baseline week.
  5. Patient must have a minimum washout period of greater than 5 times the half-life of the drug of any of the following medications: benzodiazepines, skeletal muscle relaxants, orally administered steroids, capsaicin, mexiletene, centrally acting analgesics (dextromethorphan, tramadol), opiates, topical lidocaine, anticonvulsants and serotonin and norepinephrine reuptake inhibitors (SNRIs). Anticonvulsants, SNRIs, opiates and benzodiazepines should be tapered appropriately, using product label instructions as a guide.
  6. Patients currently treated with gabapentin or pregabalin at screening may be eligible for the study, but must have a tapering period wherein the dose of gabapentin or pregabalin is reduced gradually over a period of at least 7 days plus a 2-day or 3-day washout of gabapentin or pregabalin, respectively, prior to start of the baseline week.

Exclusion Criteria:

  1. Patients who have previously not responded to treatment for PHN with gabapentin at doses of ≥ 1200 mg/day or pregabalin at doses ≥ 300 mg/day.
  2. Patients who previously experienced dose-limiting adverse effects that prevented titration of gabapentin to an effective dose.
  3. Patient is a nursing mother.
  4. Patient has hypersensitivity to gabapentin.
  5. Patient has had neurolytic or neurosurgical treatment for PHN.
  6. Patient has severe pain from causes other than PHN.
  7. Patient has used injected anesthetics or steroids within 30 days of baseline.
  8. Patient has skin conditions in the area affected by the neuropathy that could alter sensation.
  9. Patient is in an immunocompromised state.
  10. Patient has an estimated creatinine clearance of < 60 ml/min calculated using the Cockroft Gault method. If the patient fails this criterion, the Investigator may decide to conduct a 24-hour creatinine clearance test. The patient would be allowed to enroll in the study if the 24-hour test result is < 60 ml/min.
  11. Patient has had a malignancy within the past 2 years other than basal cell carcinoma.
  12. Patient has had gastric reduction surgery.
  13. Patient has severe chronic diarrhea, chronic constipation [unless attributed to drugs that will be washed out], uncontrolled irritable bowel syndrome (IBS) or unexplained weight loss.
  14. Patient has any abnormal chemistry or hematology results that are deemed by the Investigator to be clinically significant.
  15. Patient has a history of substance abuse within the past year.
  16. Patient has a history of seizure (except for infantile febrile seizure) or is at risk of seizure due to head trauma.
  17. Patient has a history of chronic hepatitis B or C, hepatitis within the past 3 months, or HIV infection.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00335933

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United States, Texas
PPD Development
Austin, Texas, United States, 78704
Sponsors and Collaborators
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Study Director: Bret Berner, Ph.D. Sponsor/Depomed, Inc.
Publications automatically indexed to this study by Identifier (NCT Number):
Layout table for additonal information Identifier: NCT00335933    
Other Study ID Numbers: 81-0045
First Posted: June 12, 2006    Key Record Dates
Last Update Posted: August 2, 2007
Last Verified: June 2006
Keywords provided by Depomed:
Postherpetic Neuralgia (PHN)
Additional relevant MeSH terms:
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Neuralgia, Postherpetic
Peripheral Nervous System Diseases
Neuromuscular Diseases
Nervous System Diseases
Neurologic Manifestations
Sensory System Agents
Peripheral Nervous System Agents
Physiological Effects of Drugs
Anti-Anxiety Agents
Tranquilizing Agents
Central Nervous System Depressants
Psychotropic Drugs
Excitatory Amino Acid Antagonists
Excitatory Amino Acid Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Antimanic Agents