Please select the eligibility criteria that correspond to the clinical trial below.
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
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 a day, is safe and effective for the treatment of postherpetic neuralgia.


Options:
A: Inclusion Criteria:

1. Men or women 18 years or older who have experienced pain for at least 6 months, but not more than 5 years after the healing of a herpes zoster skin rash(typically about 4 months after the rash first appears).
2. Patient has a pain intensity score of at least 4 on the 11-point Numerical Rating Scale (NRS). Patients should never be informed of the pain intensity criterion prior to screening or randomization.
3. Patients of child-bearing potential must have a negative serum pregnancy test at screening and a negative follow-up urine pregnancy test at randomization.
4. Patient has a mean baseline week pain intensity score of at least 4 on the 11-point NRS scale at the end of a 1-week baseline period and has completed at least 4 days of daily pain diary entries during the baseline week.
5. Patients must have a minimum washout period of greater than 5 times the half-life of the drug of several medications.
6. Patients currently treated with gabapentin pr 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 5 days followed by a two day washout prior to the Baseline Week.

Exclusion Criteria:

1. Patients who have previously not responded to treatment for PHN with gabapentin or pregabalin.
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 less than 50 ml/min.
11. Patient has had malignancy within 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.
18. Patient has any other clinically significant medical or psychological condition that, in the opinion of the Investigator would jeopardize the safety of the patient or affect the validity of the study results.
19. Continuing use of any concomitant medication excluded by Inclusion Criterion 5.
20. Patient has participated in a clinical trial of an investigational drug or device within 30 days of the screening visit.
B: Inclusion Criteria:

* Confirmed diagnosis of acute HZ
* Pain intensity \> 30 mm visual analog scale

Exclusion Criteria:

* Patients with insulin-dependent diabetes mellitus or other diseases influencing the peripheral sensibility (e.g., polyneuropathia, chronic pain syndromes, cutaneous irritations i.e. burns)
* Patients under age
* Uncompliance
* Pregnancy or lactation
* Surgery within the last 3 month
* Severe heart/lung/kidney disease
* Diseases influencing the quality of life
* Psychiatric diseases (e.g., depression, schizophrenia, dementia)
* Chronic intake of analgesics, neuroleptics, antidepressants, corticoids, alpha-agonists
* Acupuncture, transdermal electric neurostimulation or other Complementary and Alternative Medicine treatment within the last 4 weeks
* Contraindications according to the summary of product informations against analgesic treatment (i.e., metamizol, paracetamol, tramadol, morphine) or the investigational medicinal products (gabapentine, acupuncture needles)
C: Inclusion Criteria:

* You must have been diagnosed with Diabetic Neuropathic Pain
* Patient has an average daily pain score greater than or equal to 4 on an 11-point Likert scale, and patient or provider feel that a change from the current gabapentin therapy for pain management is warranted
* Patient is currently treated with gabapentin greater than or equal to 900 milligram/day, has been prescribed the current dose for at least 4 weeks, and has been at least 80% compliant with dosing, according to patient report
* Patient must agree not to change dose of gabapentin between Visits 1 and 2
* You must have stable glycemic control

Exclusion Criteria:

* Are judged prior to randomization to be at suicidal risk as defined by a score of 2 or greater on question 9 of the Beck Depression Inventory-II (BDI-II)
* Current diagnosis or history of hemangiosarcoma
* Patients with New York Heart Association Class III or IV symptoms of congestive heart failure
* Patients with uncontrolled narrow-angle glaucoma
* Presence of a current seizure disorder
D: DISEASE CHARACTERISTICS:

* Has received or is currently receiving neurotoxic chemotherapy, including taxanes (e.g., paclitaxel or docetaxel), platinum-based compounds (e.g., carboplatin, cisplatin, or oxaliplatin), or vinca alkaloids (e.g., vincristine or vinblastine)
* Pain or symptoms of peripheral neuropathy of at least 1 month duration attributed to chemotherapy-induced peripheral neuropathy

  * Average daily pain rating of at least 4 out of 10 using the pain numerical rating scale (where 0 is no pain and 10 is the worst pain possible) OR
  * Evidence of peripheral neuropathy of at least grade 1 out of 3 by ECOG Common

    * Toxicity Criteria for sensory neuropathy
* No other identified causes of painful paresthesia existing prior to chemotherapy

  * No radiotherapy-induced or malignant plexopathy
  * No lumbar or cervical radiculopathy
  * No pre-existing peripheral neuropathy of another etiology, including:

    * B12 deficiency
    * AIDS
    * Monoclonal gammopathy
    * Diabetes
    * Heavy metal poisoning
    * Amyloidosis
    * Syphilis
    * Hyperthyroidism or hypothyroidism
    * Inherited neuropathy

PATIENT CHARACTERISTICS:

Age:

* 18 and over

Life expectancy:

* At least 6 months

Renal:

* Creatinine no greater than 1.5 times upper limit of normal

Other:

* No prior allergic reaction or intolerance to gabapentin
* No significant psychiatric illness (e.g., mania, psychosis, or schizophrenia) that would preclude study compliance
* No extreme difficulty swallowing pills
* Not pregnant or nursing
* Negative pregnancy test
* Fertile patients must use effective contraception

Other:

* More than 30 days since prior investigational agent for pain control
* Concurrent selective serotonin reuptake inhibitors allowed
* Concurrent nonsteroidal anti-inflammatory drugs allowed
* No concurrent tricyclic antidepressant (e.g., amitriptyline, nortriptyline, or desipramine)\*
* No concurrent monoamine oxidase inhibitor\*
* No concurrent opioid analgesic\*
* No other concurrent adjuvant analgesic (e.g., anticonvulsant, clonazepam, or mexiletine)\*
* No concurrent topical analgesics (e.g., lidocaine gel or lidocaine patch)\*
* No concurrent amifostine
* No concurrent investigational agent for pain control NOTE: \* For pain or symptoms due to chemotherapy-induced peripheral neuropathy

Answer: A