Best Antibiotics for MRSA & Staph Infections

Staphylococcus aureus ("staph") is a common cause of skin, wound, and more serious infections. MRSA (methicillin-resistant Staph aureus) is the same bacterium, but with resistance to an entire class of antibiotics that would otherwise be first-choice — which is why identifying whether an infection is MRSA or regular ("methicillin-susceptible," MSSA) staph changes the whole treatment plan, not just fine-tunes it.

MSSA infections are often treated with cephalexin or dicloxacillin (see our skin infections page for more on that). MRSA specifically requires different antibiotics because the usual first-choice drugs don't work against it. For outpatient MRSA — a common scenario with skin and soft tissue infections — sulfamethoxazole-trimethoprim, doxycycline, and clindamycin are standard options, chosen based on the specific strain's resistance pattern where known.

More serious or bloodstream MRSA infections need IV treatment, most often with vancomycin, a long-standing reserve antibiotic for serious resistant infections. Linezolid is a newer alternative used in specific situations, including some cases where vancomycin isn't tolerated or hasn't worked well enough. Both are generally hospital-administered drugs for more severe disease, not typical outpatient prescriptions.

A bacterial culture — not just how an infection looks — is the only reliable way to know whether MRSA is actually involved, which is why a clinician may start with a broader-coverage antibiotic and narrow it once culture results come back, rather than guessing upfront.