Effect of Weight and/or Obesity on Sulfamethoxazole and Trimethoprim Concentrations
Condition: Obesity; Pharmacokinetics; MRSA; Tuberculosis; PCP
MeSH terms: Tuberculosis; Obesity
Intervention: Sulfamethoxazole/trimethoprim
Intervention description: 2 DS tablets of trimethoprim/sulfamethoxazole x 1 dose
Intervention MeSH terms: Trimethoprim; Trimethoprim, Sulfamethoxazole Drug Combination; Sulfamethoxazole
Phase: Phase 4
Study type: Interventional
Primary purpose: Treatment
Intervention model: Single Group Assignment
Masking: None (Open Label)
Enrollment: 36.0
Sex: All
Minimum age: 18 Years
Healthy volunteers: Accepts Healthy Volunteers
Keywords: Obesity; Pharmacokinetics; MRSA; Tuberculosis; PCP

Summary:

      This study will find how weight affects the dosing of a drug called sulfamethoxazole and
      trimethoprim. Currently, the amount of sulfamethoxazole and trimethoprim a patient receives
      is the same regardless of the patient's weight. The entire cohort was analyzed for the study
      outcomes. BMI groups were for recruitment purposes only and were not used for ordinal data
      analysis.

      All sulfamethoxazole and trimethoprim (Trade name is Bactrim or Septra) medication that you
      will receive in this study will be referred to as study medication within this informed
      consent form. This drug is a combination of two antibiotics, sulfamethoxazole and
      trimethoprim, which belongs to a class of medication known as "sulfones" and is approved by
      the US Food and Drug Administration (FDA) for the treatment of a wide variety of bacterial
      infections such as ear infections, urinary tract infections, bronchitis, traveler's diarrhea,
      and Pneumocystis carinii pneumonia. Sulfamethoxazole and trimethoprim is given orally.
    

Eligibility criteria:

        Inclusion Criteria:

          -  Male and female subjects, age >18 years, of all racial and ethnic origins.

          -  We are recruiting 12 normal or underweight (BMI <25kg/m2), 12 overweight or obese (BMI
             25-40 kg/m2), and 12 extremely obese (BMI > 40 kg/m2) for this study. This index is
             calculated using the volunteer's height and weight (Formula: weight (lb) / [height
             (in)]2 x 703). Half of each group will be male; the other half will be female.

        Exclusion Criteria:

          -  Pregnant or nursing or unwilling to use a reliable contraception method during the
             study. The effects of sulfamethoxazole and trimethoprim on pregnancy are unknown. In
             addition, the metabolic changes that accompany pregnancy may alter the
             concentration-time profile of sulfamethoxazole and trimethoprim, so that the pregnancy
             and post-partum state would be a confounding variable.

          -  Abnormal liver function tests: transaminases>10 times upper limit of normal, Alkaline
             phosphatase>5 times upper limit of normal, total bilirubin>5 times upper limit of
             normal.

          -  History of allergies to sulfones, sulfonamides or trimethoprim.

          -  Sulfones, sulfonamides or trimethoprim are contraindicated for any reason.

          -  Volunteers unwilling to comply with study procedures.

          -  Current suspected or documented ear infection, urinary tract infection, bronchitis,
             traveler's diarrhea, Pneumocystis carinii pneumonia, or any other bacterial infection.

          -  Volunteers with colon resection, gastric bypass, lap band, or any other conditions
             inhibiting gastric absorption of drug.

          -  Current or previous participation within 28 days of enrollment in another research
             study that involves the use of medication, contrast, or any other compound that may
             alter blood count and/or blood chemistry (liver function, kidney function or
             electrolyte balance), unless waved by PI.

          -  Donation of 450mL (one unit) of blood or more within 8 weeks (56 days) prior to study
             enrollment, unless waved by PI.

          -  Current use of medications contraindication with sulfamethoxazole/trimethoprim use:
             Bepridil, Cisapride, Dofetilide, Levomethadyl, Mesoridazine, Pimozide, Terfenadine,
             and Thioridazine. Other medications will be screened by study investigators to ensure
             the safety of research participants and maintain the quality of the study.