Neuropathic Pain Assessment Comparing Pregabalin and Paroxetine in Management of MS-induced Neuropathic Pain
Condition: Neuropathic Pain; Multiple Sclerosis
MeSH terms: Multiple Sclerosis; Neuralgia; Sclerosis
Study type: Interventional
Phase: Phase 3

Summary: 
      This is a comparative drug trial involving patients with clinically definite Multiple
      Sclerosis and documented neuropathic pain. Patients will be randomized to receive treatment
      with either paroxetine or pregabalin. After dose titration, participants will complete
      various pain scale assessments at several points during the study in order to determine the
      effectiveness of their assigned pain medication.
    

Detailed description: 
      General Objective:

      To determine the effectiveness of drug treatment in the management of MS-induced neuropathic
      pain.

      Specific Objectives:

        -  Comparatively assess the effectiveness and safety profile of pregabalin (Lyrica) and
           paroxetine (Paxil) in managing MS-induced neuropathic pain.

        -  Comparatively assess the effectiveness of pregabalin (Lyrica) and paroxetine (Paxil) in
           improving the quality-of-life associated with MS-induced neuropathic pain.

      Study Design:

      A comparative single center, randomized, open-label study involving patients with multiple
      sclerosis (MS) - induced neuropathic pain receiving treatment with either pregabalin
      (Lyrica®) or paroxetine (Paxil®).

      The study will run for approximately one year, requiring individual participants' involvement
      for 8 weeks.

      Participant Selection:

      Individuals with clinically definite MS presenting with symptoms of neuropathic pain (as
      determined by clinician) that express interest in the study will be screened for eligibility.

      Inclusion Criteria:

        -  Patients presenting with symptoms of neuropathic pain as determined by clinician, with a
           minimum VAS pain score of 40mm as determined by a baseline score (0mm = no pain, 100mm =
           worst pain).

        -  Male and female patients between the ages of 18 and 65 years old.

        -  Clinically definite multiple sclerosis as defined by clinical history review,
           neurological examination and positive MRI.

        -  EDSS scores of < 6.0.

        -  No known hypersensitivity to the study medications.

        -  Negative serum pregnancy test for all female patients of childbearing age; not currently
           breastfeeding.

        -  Not currently treated with pregabalin, gabapentin, paroxetine or another SSRI.

        -  No previous treatment failures with pregabalin or paroxetine.

        -  Baseline creatinine clearance (Clcr) of > 50mL/min.

        -  No significant hepatic insufficiency.

        -  If on other pain medications, must be on stable dose for at least 6 months and other
           medications must not elicit significant drug-drug interactions with study medications.

      Study Procedures:

      After obtaining informed consent (Visit 1), participants undergo various assessments,
      including pain/quality-of-life analyses (SF-MPQ, SF-36, VAS), physical/neurological exam and
      a standard blood test. Based on above inclusion criteria, participants will be randomized to
      either Group A (paroxetine) or Group B (pregabalin). Participants will be provided with
      prescriptions for assigned study medications as well as dosing instructions. A pain diary
      consisting of a single VAS scale will be provided to the participants, which are to be
      completed daily upon waking and should be used to rate the individual's average pain over the
      last 24 hours. Dosages of study medications will be titrated slowly over 3 weeks to lower
      likelihood of adverse events. After the three week titration phase, participants will return
      to the clinic (Visit 2) for a follow-up. Pain/quality-of-life assessments (as at Visit 1)
      will be completed again at this visit. In addition, average pain scores will be determined
      from daily pain diaries. Adverse events will be discussed and individual tolerability will be
      assessed. At this point, it will be determined if the patient will be maintained at the
      target dosage or if the dosage will be lowered to accommodate patient tolerability.
      Participants will be maintained at determined maintenance dose for 5 weeks, after which they
      will return to the clinic (Visit 3) for a final follow-up assessment. Participants will
      complete final pain/quality-of-life assessments, as well as the "Patient-rated Global
      Impression of Change". Adverse events and average pain scores will be reviewed. At the
      conclusion of the 8-week treatment phase, participants will have the option of remaining on
      their current study medication or be tapered off.
    

Intervention name(s): paroxetine; pregabalin
Intervention type(s): Drug; Drug
Intervention MeSH terms: Pregabalin; Paroxetine
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Neuropathic pain; Multiple Sclerosis; pregabalin; paroxetine