Diabetic Peripheral Neuropathic Pain (DPNP)

Allocation: Randomized Stratified; Intervention Model: Cross-over Versus Comparator +
Placebo

Inclusion Criteria:

- Type I or Type II diabetes with painful, distal, symmetrical, sensory-motor
neuropathy attributed to diabetes, of at least 6 months duration.

- Score of ≥3 on Michigan Neuropathy Screening Instrument

- The patient is able to satisfactorily complete, in the Investigator's judgment, the
Cognitive Battery.

- Based on patient diary information collected during the Screening/Baseline period,
the patient has completed at least 5 of 7 daily diary entries and has an average
weekly pain rating of at least 4 on the 11-point pain rating scale, in the week
immediately prior to randomization (Baseline Visit).

- Male or female, 18-85 years of age.

Exclusion Criteria:

- History of complete lack of response to Pregabalin (at least 300 mg qd for 4 weeks)
or Gabapentin (at least 1800 mg qd for 4 weeks).

- Other severe pain that may potentially confound pain assessment.

- Hemoglobin A1c > 9%

- Hemoglobin ≤ 9 g/dL

- Estimated glomerular filtration rate (eGFR) according to the re-expressed abbreviated
(four-variable) Modification of Diet in Renal Disease (MDRD) Study equation ≤
50ml/min/1.73m2

- Patients who have been on a stable dose of anticonvulsant, anticholinergic, diabetic
meds, nicotine replacements, or any other smoking cessation meds for <4 weeks prior
to randomization. Patients who are on stable doses for ≥ 4 weeks prior to
randomization are allowed, however, there should be no adjustments to the dose of
these medications during study.

- Patients currently on more than one drug for treatment of neuropathic pain (low dose
opioids or antidepressants). Patients are allowed to participate if on a stable dose
of for at least 4 weeks prior to randomization (Day1) and should remain stable during
study.