More antibiotic use, no more resistance: daptomycin and linezolid hold the line

Concern about fueling antibiotic resistance often limits how freely clinicians prescribe powerful drugs like daptomycin and linezolid. But a new 8-year study suggests those concerns may be overstated — at least for gram-positive bacteria.

Researchers at UCHealth University of Colorado Hospital analyzed over 19,000 Staphylococcus and Enterococcus isolates from 2016 to 2024. After the hospital relaxed prescribing restrictions between 2019 and 2021 — favoring linezolid for skin and respiratory infections and daptomycin for bloodstream infections — use of both drugs surged. Yet resistance rates didn't follow.

By the Numbers:

• Linezolid use jumped nearly 10x: from 4.6 to 43.7 days of therapy per 1,000 patient days
• Daptomycin use doubled: from 7.6 to 15.7 days of therapy per 1,000 patient days
• Daptomycin resistance stayed below 1% across all Staphylococcus groups
• Zero linezolid resistance detected in any S. aureus or MRSA isolates
• Linezolid MICs in MRSA actually declined from 1.797 to 1.193 mcg/mL

Why it matters: These findings offer clinicians and stewardship programs a confidence boost — broader use of daptomycin and linezolid may be sustainable without triggering resistance, potentially improving outcomes for serious gram-positive infections like MRSA and VRE.