Program Schedule

A Randomized, Double-Blind, Placebo-Controlled Trial of Trimethoprim-sulfamethoxazole vs. Placebo for Patients with an Incised and Drained Cutaneous Abscess

Session: Oral Abstract Session: Clinical Trials
Saturday, October 11, 2014: 10:45 AM
Room: The Pennsylvania Convention Center: 109-AB



U.S. emergency department (ED) visits for cutaneous abscess have increased corresponding with the emergence of methicillin-resistant Staphylococcus aureus (MRSA). The role of antibiotics for patients with a drained abscess is unclear.


We conducted a randomized double-blind, trial at 5 U.S. EDs to determine whether 7 days of trimethoprim-sulfamethoxazole (TMP/SMX 160 mg/800 mg BID) is superior to placebo for treatment of patients >12 years old with an acute uncomplicated skin abscess receiving drainage and treated as an outpatient. The primary outcome was clinical cure of the abscess at the test-of-cure visit (TOC, 7-14 days after the end of treatment) in the per-protocol (PP) population.


Of 1,265 patients enrolled, 1,247 (98.6%) were randomized to TMP/SMX or placebo and received ≥1 dose. Subjects were median age 35 years (range, 14-73). Median maximal dimension of the abscess cavity and associated erythema were 2.5 cm and 6.5 cm, respectively; 44.3% grew MRSA. In the PP population, clinical cure occurred in 487/ 524 (92.9%) TMP/SMX-treated compared to 457/533 (85.7%) placebo-treated subjects (difference 7.2%; 95% CI 3.2%-11.2%). Similar differences were found for abscess cure in the intention-to-treat populations. Compared to the placebo group, the TMP/SMX group had lower rates of subsequent hospitalization (19/524 [3.6%] vs. 34/533 [6.4%]; difference -2.8%; 95% CI -5.6%-0.1%), surgeries (18/524 [3.4%] vs. 46/533 [8.6%]; difference -5.2%; 95% CI -8.2%--2.2%), new skin infections at a different location (16/524 [3.1%] vs. 55/533 [10.3%]; difference -7.3%; 95% CI -10.4%- 4.1%), and similar infections in their household (9/524 [1.7%] vs. 22/533 [4.1%]; difference 2.4%; 95% CI -4.6%--0.2%) through TOC. At 42-56 days after treatment, new infection rates were 10.9% (57/524) in TMP/SMX- and 19.1% (102/533) in placebo-treated subjects (difference -8.3%; 95% CI -12.7%- -3.8%). TMP/SMX was associated with slightly more, mostly mild, gastrointestinal side effects. There were no serious drug-related adverse events.




Compared to placebo, TMP/SMX is safe and associated with improved outcomes for patients with an acute cutaneous abscess receiving drainage and treated as an outpatient.


David Talan, MD. FIDSA, FACEP1,2, William Mower, MD, PhD2, Fredrick Abrahamian, D.O.2,3, Anusha Krishnadasan, PhD3, Frank Lovecchio, DO, MPH4, David Karras, MD5, Mark Steele, MD6, Richard Rothman, MD, PhD7 and Gregory Moran, MD, FIDSA, FACEP1,2, (1)Emergency Medicine/Infectious Diseases, Olive View-UCLA Medical Center, Sylmar, CA, (2)Emergency Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, (3)Emergency Medicine, Olive View-UCLA Medical Center, Sylmar, CA, (4)Emergency Medicine, Maricopa Medical Center, Phoenix, AZ, (5)Emergency Medicine, Temple University School of Medicine, Philadelphia, PA, (6)Emergency Medicine, Truman Medical Center/University of Kansas City, Kansas City, MO, (7)Emergency Medicine, Johns Hopkins University School of Medicine, Baltimore, MD


D. Talan, NIAID/NIH/DHHS: Research Contractor, Research support

W. Mower, None

F. Abrahamian, None

A. Krishnadasan, None

F. Lovecchio, None

D. Karras, None

M. Steele, None

R. Rothman, None

G. Moran, None

See more of: Clinical Trials
See more of: Oral Abstract Session

Findings in the abstracts are embargoed until 12:01 a.m. EDT, Oct. 8th with the exception of research findings presented at the IDWeek press conferences.

Sponsoring Societies:

© 2014, All Rights Reserved.

Follow IDWeek