Magnesium Supplements In The Treatment Of Pseudoxanthoma Elasticum (PXE)
Condition: Pseudoxanthoma Elasticum
MeSH terms: Pseudoxanthoma Elasticum
Intervention: Magnesium Oxide; Placebo
Intervention description: Part 1: 1000 mg elemental magnesium (given as one 800 mg capsule of magnesium oxide two times daily).
Part 2: 1500 mg elemental magnesium (given as two 500 mg capsules of magnesium oxide in the morning and three 500 mg capsules of magnesium oxide in the evening).; 1000 mg (one 500 mg capsule two times daily) of placebo.
Intervention MeSH terms: Magnesium Oxide
Phase: Phase 2
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Enrollment: 44.0
Sex: All
Minimum age: 18 Years
Healthy volunteers: No
Keywords: pseudoxanthoma elasticum; calcification

Summary:

      The purpose of this study is to evaluate the effectiveness of magnesium oxide supplements on
      the reversal of calcium deposits in the skin, and the yellow bumps and folds of skin in
      subjects with pseudoxanthoma elasticum (PXE). Magnesium oxide is a dietary supplement that
      has been shown in some research to reduce these calcium deposits. This study consists of two
      parts. The first part is a year-long, double-blind, placebo-controlled study. Part two is an
      open-label, year-long study. In Part 1, qualified subjects will be randomized to receive
      either magnesium oxide supplements or placebo, in a 1:1 ratio for the first 12 months. The
      starting dose will be 1000 mg daily, and depending on tolerability, doses may be decreased.
      Baseline evaluations will be comprised of: blood tests; clinical evaluations; skin biopsy;
      eye examination; bone density test; and photography of skin lesions. Subjects will be
      evaluated at week 2, week 6, month 3, and then every 3 months during the first year. Upon
      completion of the first year, barring any safety concerns, all subjects will be administered
      magnesium oxide supplements for up to one additional year. Subjects will undergo the same
      evaluations/ procedures every 3 months. We hypothesize that the magnesium oxide will cause a
      reduction in calcifications in the subject's soft tissue/skin. Funding Source - FDA OOPD.
    

Eligibility criteria:

        Inclusion Criteria:

          -  Male or female subject at least 18 years of age

          -  If female, the subject is not pregnant or nursing

          -  If female of child bearing potential, the subject has a negative urine pregnancy test
             at the first visit, and agrees to use an approved method of contraception (hormonal
             contraceptives [birth control pills, implants [Norplant] or injections [DepoProvera]);
             intrauterine device (IUD); two forms of barrier methods [condoms and diaphragm]; or
             abstinence (no sexual activity) throughout the entire study

          -  Biopsy confirmed diagnosis of pseudoxanthoma elasticum (documenting some calcification
             of elastic fibers)

          -  Subject has a clinical disease severity grade of at least "1" (Poorly defined, barely
             visible macules) at screening.

          -  Normal kidney function tests

        Exclusion Criteria:

          -  Any subject who is pregnant or becomes pregnant during the study

          -  Subjects with a serum creatinine greater than 1.6 mg/dL

          -  Subjects with hypermagnesemia, hypokalemia, or idiopathic hypercalciuria

          -  Subjects with kidney disease or renal tubular defects (eg. Fanconi's syndrome), or on
             dialysis

          -  Subjects with hypothyroidism or hypoparathyroidism or primary hyperparathyroidism

          -  Subjects with acute gout

          -  Subjects with malabsorption, or osteomalacia

          -  Subjects on diuretics, magnesium containing antacids, or anabolic steroids

          -  Subjects with Cushing's syndrome

          -  Subjects receiving lithium and those with significant psychiatric disorders that would
             likely interfere with participation in this study

          -  Subjects taking anti-seizures medications and anti-arrhythmics medications

          -  Subjects on tetracycline or metronidazole and ace inhibitors

          -  Subjects taking cyclosporine or calcineurin inhibitors