Which is the most appropriate treatment option for once-daily outpatient intravenous therapy for a patient with methicillin-resistant Staphylococcus aureus?

Daptomycin is the most suitable treatment option for outpatient intravenous therapy for a patient with methicillin-resistant Staphylococcus aureus (MRSA). It is a lipopeptide antibiotic specifically designed to treat infections caused by Gram-positive bacteria, including MRSA. Daptomycin works by disrupting bacterial cell membrane function, leading to cell death, and is effective in treating serious infections due to its rapid bactericidal activity.

When considering the need for once-daily administration, daptomycin's dosing schedule is an advantage, as it can be dosed once daily based on renal function, allowing for convenient outpatient therapy without compromising efficacy. This characteristic makes it particularly appealing for patients requiring long-term intravenous treatment outside of a hospital setting.

In contrast, other options have limitations in either their effectiveness against MRSA or dosing schedules that may not fit the outpatient model well. For example, ertapenem, while broad-spectrum, does not reliably cover MRSA. Ceftaroline is a cephalosporin that does cover MRSA but may require more frequent dosing or may not be the preferred first-line choice in all cases. Piperacillin/tazobactam is a combination antibiotic effective against many Gram-negative organisms and some Gram-positive bacteria