Completed

TODOSDoxycycline vs Trimethoprim-Sulfamethoxazole for Skin and Soft Tissue Infections in Areas with High CA-MRSA Prevalence

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Study Aim

This study aims to compare the effectiveness of Doxycycline and Trimethoprim-Sulfamethoxazole in treating skin and soft tissue infections in people living in areas with high prevalence of community-acquired Methicillin-resistant Staphylococcus aureus, by evaluating clinical cure at an early clinical response visit.

What is being tested

TMP-SMX

+ DOXY

Drug
Who is being recruted

Cellulitis+6

+ Connective Tissue Diseases

+ Infections

From 9 to 85 Years
+41 Eligibility Criteria
See all eligibility criteria
How is the trial designed

Treatment Study

Phase 2
Interventional
Study Start: November 2018
See protocol details

Summary

Principal SponsorLundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center
Last updated: January 28, 2026
Sourced from a government-validated database.Claim as a partner

Study start date: November 26, 2018

Actual date on which the first participant was enrolled.

This study focuses on understanding the best treatment for uncomplicated skin and soft tissue infections, like abscesses and cellulitis, particularly in areas with a high presence of a resistant bacteria known as CA-MRSA. The trial involves both children and adults from Los Angeles and St. Louis. These locations have a high number of cases caused by CA-MRSA, which makes it crucial to find effective treatments. The study compares two antibiotics, Doxycycline (DOXY) and Trimethoprim-Sulfamethoxazole (TMP-SMX), which are not well-studied for these infections but are frequently used. The goal is to see which medication is more effective in curing infections and has fewer side effects, thereby helping doctors choose the best option for treating patients with these common skin infections. Participants in this trial will be randomly assigned to receive either Doxycycline or TMP-SMX, in a setting that ensures neither they nor the doctors know which treatment is given, to maintain objectivity. The study measures success by checking if the infection is cured without any complications like fever, lesion spreading, or needing additional antibiotics or surgeries. The trial also looks at how often the infection comes back or doesn't respond to treatment, especially in those who have Staphylococcus aureus bacteria in their nose or throat. This research will help determine the safest and most effective treatment options for dealing with these challenging skin infections.

Official TitleShort and Long Term Outcomes of Doxycycline Versus Trimethoprim-Sulfamethoxazole for Treatment of Uncomplicated Skin and Soft Tissue Infections
Principal SponsorLundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center
Last updated: January 28, 2026
Sourced from a government-validated database.Claim as a partner

Protocol

This section provides details of the study plan, including how the study is designed and what the study is measuring.
Design Details

269 patients to be enrolled

Total number of participants that the clinical trial aims to recruit.

Treatment Study

These studies test new ways to treat a disease, condition, or health issue. The goal is to see if a new drug, therapy, or approach works better or has fewer side effects than existing options.



Eligibility

Researchers look for people who fit a certain description, called eligibility criteria: person's general health condition or prior treatments.
Conditions
Criteria

Any sex

Biological sex of participants that are eligible to enroll.

From 9 to 85 Years

Range of ages for which participants are eligible to join.

Healthy volunteers not allowed

If individuals who are healthy and do not have the condition being studied can participate.

Conditions

Pathology

CellulitisConnective Tissue DiseasesInfectionsInflammationPathologic ProcessesSkin Diseases, InfectiousSuppurationPathological Conditions, Signs and SymptomsSkin and Connective Tissue Diseases

Criteria

10 inclusion criteria required to participate
For women of childbearing potential, the participant agrees to use birth control for the 7 days on the study medication and 7 days after completion of study medication

Received prior systemic antibacterial therapy with anti-staphylococcal activity for a skin infection and are not on it currently, and have relapse/recurrence of skin infection.

Age 9 years to 85 years

Able to complete the informed consent process or, if a minor, a parent or guardian who is able to complete the informed consent process; an assent form also will be completed for children age 9 and older

Show More Criteria

31 exclusion criteria prevent from participating
Heart rate less than 45 beats per minute (BPM)

Previous enrollment in this protocol

Participation in another clinical trial within the previous 30 days

Severe or morbid obesity with a body mass index (BMI) >45 kg/m2; patients above BMI >45 can be enrolled if their weight is < 100 kg kg/m2.

Show More Criteria

Study Plan

Find out more about all the medication administered in this study, their detailed description and what they involve.
Treatment Groups
Study Objectives

2 intervention groups are designated in this study

This study does not include a placebo group 

Treatment Groups

Group I

Experimental
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

Experimental
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.

Study Objectives

Primary Objectives

Secondary Objectives

Study Centers

These are the hospitals, clinics, or research facilities where the trial is being conducted. You can find the location closest to you and its status.

This study has 3 locations

Suspended

Olive View-UCLA Medical Center

Sylmar, United StatesOpen Olive View-UCLA Medical Center in Google Maps
Suspended

Harbor-UCLA Medical Center

Torrance, United States
Suspended

Washington University

St Louis, United States
Completed3 Study Centers