UMEM Educational Pearls

Title: Add Strep Coverage to Outpatient Cellulitis Treatment Regimens

Category: Pharmacology & Therapeutics

Keywords: cellulitis, cephalexin, sulfamethoxazole/trimethoprim, Bactrim, streptococcus (PubMed Search)

Posted: 5/20/2013 by Bryan Hayes, PharmD (Updated: 5/31/2013)
Click here to contact Bryan Hayes, PharmD

Background

In the current era of community-acquired MRSA (CA-MRSA), most of our outpatient treatment options for cellulitis aim to cover MRSA. Choices include sulfamethoxazole/trimethoprim (SMZ-TMP), doxycycline, linezolid, and clindamycin (depending on local susceptibility patterns).

A New Study

In a double-blind, placebo-controlled trial 146 patients with cellulitis were randomized to receive cephalexin alone or cephalexin + SMZ-TMP for 7-14 days
Lots of exclusion criteria basically narrowed the patient population to uncomplicated cellultits with no history of diabetes or other immunocompromising conditions
Cure rates up to 30 days post-treatment were the same between the two groups (>80%)

Take Home Clinical Points

Even in communities with high prevalence of MRSA, uncomplicated cellulitis cases without pus generally seem to be strep species.
Therefore, make sure to include an anti-streptococcal component (such as cephalexin) to the MRSA agent (doxycycline or SMZ-TMP). Clindamycin has sufficient strep coverage by itself (but may not adequately cover MRSA).
Given the potential for MRSA infections to deteriorate quickly and the inability to differentiate staph from strep without cultures, MRSA coverage should still be considered.

References

Pallin DJ, et al. Clinical Trial: Comparative Effectiveness of Cephalexin Plus Trimethoprim-Sulfamethoxazole Versus Cephalexin Alone for Treatment of Uncomplicated Cellulitis: A Randomized Controlled Trial. Clinical Infectious Diseases 2013;56(12):1754-62. [PMID 23457080]

Follow me on Twitter (@PharmERToxGuy)