Study of New Antibiotic Regimen for the Treatment of Uncomplicated Cellulitis in Emergency Department Patients

Study Overview
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Brief Summary
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The primary aim of this study is to quantify the effectiveness of Bactrim as additional therapy for the treatment of uncomplicated cellulitis in adults, by comparing: standard therapy plus Bactrim, versus standard therapy plus placebo. The primary hypothesis of this study is that, in light of increasing CA-MRSA prevalence, subjects treated with standard therapy plus Bactrim will have higher cure rates than those treated with standard therapy plus placebo.

Official Title
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Randomized Trial of Trimethoprim-Sulfamethoxazole Versus Placebo Added to Standard Treatment of Uncomplicated Cellulitis in Emergency Department Patients

Conditions
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Cellulitis

Intervention / Treatment
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* Drug: trimethoprim-sulfamethoxazole
* Drug: Cephalexin


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria Must have cellulitis as defined here: Definition A (preferred definition): Recent onset of soft tissue erythema, considered by the treating clinician to be bacterial in origin, and associated with signs of infection that include at least two of the following: pain, swelling, warmth, fever, lymphangitis, induration, or ulceration. Definition B (ONLY for darkly-pigmented subjects who cannot use Definition A): Recent onset of soft tissue color change, pain, or swelling, considered by the treating clinician to be bacterial in origin, and at least one of the following: warmth, fever, induration, or ulceration Clinical (non-research) attending physician agrees with treatment with cephalexin until 3 days after all symptoms gone, using our weight-based dosing Responsible clinical attending physician comfortable with adding trimethoprim-sulfamethoxazole vs. placebo to the above Subject understands the study and signs written informed consent. Subject agrees to drink at least 1 liter of fluid per day. Subject will commit to all follow-up appointments Exclusion Criteria: Age < 12 months or weight <15 kg Current skin infection has already been treated Allergy to sulfa drugs History of severe allergic reaction to penicillin (defined as anaphylactoid reaction, angioedema, bronchospasm) Current use of any antibiotic (other than topicals) Diabetes mellitus Cellulitis complicated by underlying peripheral vascular disease Renal insufficiency, defined as patient report, clinical suspicion, or creatinine>1.3 or EGFR<60 on the last-available set of chemistry results in our computer system Hospital admission required Presence of > 1 cc of purulent discharge at any time Cellulitis involving an indwelling vascular, enteric, or urinary catheter Immunocompromise of any etiology Pregnancy Breast feeding Facial cellulitis (infection is above the clavicles) Cellulitis associated with marine or freshwater injury, or animal or human bite. (Insect bites not excluded.) History of glucose-6-phosphate dehydrogenase deficiency Taking coumadin (warfarin), methotrexate, cisapride, phenytoin (dilantin), digoxin, or dofetilide Known megaloblastic anemia due to folate deficiency.

Ages Eligible for Study
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Minimum Age: 12 Months

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Standard therapy<br>cephalexin plus placebo | Drug: Cephalexin<br>* Weight-based dosing in capsule or suspension form according to the following scale: 15-19 kg (33-42 lbs): Cephalexin 300 mg four times daily 20-24 kg (42-53 lbs): Cephalexin 400 mg four times daily 25-29 kg (53-64 lbs): Cephalexin 500 mg four times daily 29-60 kg (64-132 lbs): Cephalexin 500 mg four times daily 60-80 kg (132-176 lbs): Cephalexin 1000 mg three times daily > 80 kg (176 lbs): Cephalexin 1000 mg four times daily<br>* Other names: Keflex;|
| Experimental: Standard plus anti-CA-MRSA<br>cephalexin plus trimethoprim-sulfamethoxazole | Drug: trimethoprim-sulfamethoxazole<br>* Weight-based dosing in capsule or suspension form according to the following scale: 15-19 kg (33-42 lbs): trimethoprim-sulfamethoxazole 40/200 mg four times daily 20-24 kg (42-53 lbs): trimethoprim-sulfamethoxazole 60/300 mg four times daily 25-29 kg (53-64 lbs): trimethoprim-sulfamethoxazole 72/360 mg four times daily 29-60 kg (64-132 lbs): trimethoprim-sulfamethoxazole 80/400 mg four times daily 60 kg (132 lbs): trimethoprim-sulfamethoxazole 80/400 mg four times daily 60-80 kg (132-176 lbs): trimethoprim-sulfamethoxazole 160/800 mg three times daily > 80 kg (176 lbs): trimethoprim-sulfamethoxazole 160/800 mg four times daily<br>* Other names: Septra;Drug: Cephalexin<br>* Weight-based dosing in capsule or suspension form according to the following scale: 15-19 kg (33-42 lbs): Cephalexin 300 mg four times daily 20-24 kg (42-53 lbs): Cephalexin 400 mg four times daily 25-29 kg (53-64 lbs): Cephalexin 500 mg four times daily 29-60 kg (64-132 lbs): Cephalexin 500 mg four times daily 60-80 kg (132-176 lbs): Cephalexin 1000 mg three times daily > 80 kg (176 lbs): Cephalexin 1000 mg four times daily<br>* Other names: Keflex;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Relative Efficacy | Proportion of subjects in each arm with successful treatment. Treatment success was assessed by physician examination at 12 +/- 2 days. Non-success was defined as subsequent hospitalization, change in antibiotics, surgical or needle drainage of an abscess, or recurrence of infection within 30 days. Cure was defined as resolution of all symptoms other than mild residual erythema or edema. We confirmed the determination of cure by telephone interview and medical record review at 30 +/- 2 days. | 12 +/- 2 days; 30 +/- 2 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Progression to Abscess | Proportion of subjects in each arm with progression from cellulitis to abscess. | 12 +/- 2 days, 30 days +/- 2 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Cellulitis, Bactrim, Trimethoprim Sulfamethoxazole, MRSA, Methicillin-resistant Staphylococcus aureus