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Antibiotic

Doxycycline vs TMP-SMX for Skin Infections (TODOS Trial)

Phase 2
Waitlist Available
Led By Loren G Miller, MD
Research Sponsored by Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center
Eligibility Criteria Checklist
Specific guidelines that determine who can or cannot participate in a clinical trial
Must have
Age 9 years to 85 years
Diagnosis of uSSTI, either purulent cellulitis (defined as an inflammation of skin and associated skin structures) or abscess (defined as a circumscribed collection of pus), evidenced by at least 2 of the following localized signs or symptoms on the skin for at least 24 hours: Erythema, Swelling or induration, Local warmth, Purulent drainage, Tenderness to palpation or pain, Pus or drainage from wound that can be sent for clinical culture
Must not have
Hospitalization within the prior 14 days
Oral temperature (or equivalent rectal, tympanic membrane, axillary defined in Table 2) greater than age-specific critical value: Age 9 to 17 years: > 38.5° C (101.3° F), Age ≥ 18 years: > 38.5° C (101.3° F)
Timeline
Screening 3 weeks
Treatment Varies
Follow Up day 2-3 (48-72 hours)
Awards & highlights
All Individual Drugs Already Approved
Approved for 60 Other Conditions
No Placebo-Only Group

Summary

This trial will compare DOXY to TMP/SMX in terms of safety and efficacy for the treatment of uSSTI.

Who is the study for?
This trial is for people aged 9 to 85 with uncomplicated skin and soft tissue infections like boils or cellulitis. Participants must be able to take oral antibiotics, follow the study plan, and not have been hospitalized recently. Women who can get pregnant should use birth control during and after the study. Those with severe health issues or on certain medications cannot join.
What is being tested?
The trial compares two antibiotics: doxycycline (DOXY) and trimethoprim-sulfamethoxazole (TMP/SMX), to see which one better treats simple skin infections that show signs like redness, swelling, warmth, pus drainage, or pain.
What are the potential side effects?
Possible side effects of DOXY include sun sensitivity, stomach upset, teeth discoloration in children; TMP/SMX may cause rash, nausea, blood disorders or kidney issues. Allergic reactions are also a risk with both drugs.

Eligibility Criteria

Inclusion Criteria

You may be eligible if you check “Yes” for the criteria below
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I am between 9 and 85 years old.
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I have a skin infection with redness, swelling, warmth, or pus.

Exclusion Criteria

You may be eligible for the trial if you check “No” for criteria below:
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I have not been hospitalized in the last 2 weeks.
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My temperature is above 101.3°F.
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I am not taking any medications like warfarin, phenytoin, or methotrexate.
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I have or might have a severe infection caused by S. aureus or GAS.
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I have a serious infection that needs special treatment or antibiotics.
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I have a history of G6PD deficiency.
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I have a severe immune system condition or have had significant treatments affecting my immune system.
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I am currently admitted to a hospital.
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My heart rate is over 120 beats per minute.
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I have cellulitis without any pus or drainage.
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My blood pressure is below 90 mm Hg.
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I only have a minor skin infection that can be treated with creams or minor surgery.
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I have been hospitalized for a skin infection or another condition.

Timeline

Screening ~ 3 weeks
Treatment ~ Varies
Follow Up ~day 2-3 (48-72 hours)
This trial's timeline: 3 weeks for screening, Varies for treatment, and day 2-3 (48-72 hours) for reporting.

Treatment Details

Study Objectives

Study objectives can provide a clearer picture of what you can expect from a treatment.
Primary study objectives
Clinical cure at Early Clinical Response (ECR) visit
Secondary study objectives
Adverse events
Adverse events that are treatment limiting
Clinical cure at the End of Treatment (EOT) visit
+4 more

Awards & Highlights

All Individual Drugs Already Approved
Therapies where all constituent drugs have already been approved are likely to have better-understood side effect profiles.
Approved for 60 Other Conditions
This treatment demonstrated efficacy for 60 other conditions.
No Placebo-Only Group
All patients enrolled in this study will receive some form of active treatment.

Trial Design

2Treatment groups
Experimental Treatment
Group I: Trimethoprim/sulfamethoxazole (TMP-SMX)Experimental Treatment1 Intervention
TMP-SMX will be dosed as follows: for adults, 160/800 mg administered as two single strength (SS) over-encapsulated tablets (equivalent to one double strength (DS) tablet) twice daily. As dosages of these medications may be lower in children with lower body weight (\<40 kg), we will use weight based liquid medications for children \< 40 kg (TMP/SMX dosed based on 8-10 mg/kg of TMP daily, divided into two daily doses) for those children who are under 40 kg in weight. As dosages of these medications are higher in persons with high body weight (\>100 kg), we will use TMP/SMX 160/800 mg administered as four single strength (SS) over-encapsulated tablets (equivalent to two double strength (DS) tablet) twice daily.
Group II: Doxycycline (DOXY)Experimental Treatment1 Intervention
DOXY will be dosed as follows: for adults, two 50 mg tabs (100 mg total) given twice daily. As dosages of these medications may be lower in children with lower body weight (\<40 kg), we will use weight based liquid medications for children \< 40 kg (DOXY 2.2 mg/kg twice daily) for those children who are under 40 kg in weight. The doxycycline dose will remain the same for persons with high body weight (\>100 kg) and four additional placebo tabs will be given to subjects \> 100 kg randomized to doxycycline.

Find a Location

Who is running the clinical trial?

Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical CenterLead Sponsor
104 Previous Clinical Trials
46,121 Total Patients Enrolled
National Institute of Allergy and Infectious Diseases (NIAID)NIH
3,326 Previous Clinical Trials
5,365,415 Total Patients Enrolled
Washington University School of MedicineOTHER
1,995 Previous Clinical Trials
2,296,259 Total Patients Enrolled

Media Library

Skin Infections Research Study Groups: Trimethoprim/sulfamethoxazole (TMP-SMX), Doxycycline (DOXY)
~66 spots leftby Dec 2025