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学位を持っても、センスのない、感染制御専門薬剤師のブログ.  I have Ph.D. but less sense ID pharmacist.

Effect of Cephalexin Plus Trimethoprim-Sulfamethoxazole vs Cephalexin Alone on Clinical Cure of Uncomplicated Cellulitis: A Randomized Clinical Trial.

Effect of Cephalexin Plus Trimethoprim-Sulfamethoxazole vs Cephalexin Alone on Clinical Cure of Uncomplicated Cellulitis: A Randomized Clinical Trial.


2017年5月 JAMA に報告された、米国5施設による単純性蜂窩織炎に対しするCephalexin Plus Trimethoprim-Sulfamethoxazole vs Cephalexin Aloneの優越性試験。



 Key Points

Question Doescephalexinplustrimethoprim-sulfamethoxazole yield higher clinical cure rates than cephalexin alone for treatment of patients with uncomplicated cellulitis?

Findings Inthisrandomizedclinicaltrialof500patients
with cellulitis, the clinical cure rate was not significantly
different between those treated with cephalexin plus trimethoprim-sulfamethoxazole vs cephalexin plus placebo (83.5% vs 85.5% in the per-protocol analysis and 76.2% vs 69.0% in the modified intention-to-treat analysis). However, the 95% confidence interval for the difference in the intention-to-treat analysis was −1.0% to +15.5%, which included the minimal clinically important difference of 10%.

Meaning Additionoftrimethoprim-sulfamethoxazoleto cephalexin did not result in a statistically significant improvement in clinical cure for uncomplicated cellulitis. However, because the imprecision around the findings in the modified intention-to-treat analysis included a clinically important difference favoring the combination, further research may be needed.




P : outpatients older than 12 years with cellulitis and no wound, purulent drainage, or abscess

E : Cephalexin, 500 mg 4 times daily, plus trimethoprim-sulfamethoxazole, 320 mg/1600 mg twice daily, for 7 days (n = 248 participants) 

C : cephalexin plus placebo for 7 days (n = 248 participants).

O : 

clinical cure occurred in 182 (83.5%) of 218 participants in the cephalexin plus trimethoprim-sulfamethoxazole group vs 165 (85.5%) of 193 in the cephalexin group (difference, -2.0%; 95% CI, -9.7% to 5.7%; P = .50).

intention-to-treat population, clinical cure occurred in 189 (76.2%) of 248 participants in the cephalexin plus trimethoprim-sulfamethoxazole group vs 171 (69.0%) of 248 in the cephalexin group (difference, 7.3%; 95% CI, -1.0% to 15.5%; P = .07).

T : Multicenter, double-blind, randomized superiority trial in 5 US emergency departments


Fig and Tab








First, the Infectious Diseases Society of America skin infection guidelines recommend antibiotic regimens with activity against MRSA when cellulitis is accompanied by systemic signs of infection, penetrat- ing trauma, evidence of MRSA elsewhere, or history of injection drug use. Although enrollment of individuals with some of these conditions was allowed in the current study, clinicians may have been biased against their participation, thus leaving a selected population that was at relatively lower risk of treatment failure.


Second, even with 500 participants, the power of this trial is limited such that the possibility that regimens with activity against MRSA could improve outcomes in some subgroups cannot be excluded.


Third, the most recent data were collected 5 years ago, and it is unknown whether the findings reflect the bacteriology or antimicrobial susceptibility of cellulitis among patients currently treated in emergency departments. However, in a prior study, MRSA prevalence and susceptibility to trimethoprim-sulfamethoxazole did not change over a 4-year interval (2004-2008) at these sites.


Fourth, to try to ensure accurate diagnosis of cellulitis without abscess, bedside ultrasound was used to exclude an occult fluid collection. Although most US emergency departments have bedside ultrasound available, this may not be available in some settings; these findings should be cautiously applied to patients in whom abscess is not identified based on physical examination alone.












西伊豆早朝カンファランH28.9 西伊豆健育会病院 仲田和正先生

蜂窩織炎(CellulitisA Review)JAMA July19,2016