Daptomycin should not be used for pneumonia because it is inactivated by pulmonary surfactant.

Daptomycin should not be used for pneumonia because it is inactivated by pulmonary surfactant.

• A. Mupirocin
• B. Linezolid
• C. Daptomycin
• D. Ceftriaxone

Answer: (C)

Daptomycin should not be used for pneumonia because pulmonary surfactant inactivates it. Daptomycin works by binding to Gram-positive bacterial membranes in a calcium-dependent way, forming pores and causing rapid depolarization that kills the bacteria. However, in the lungs, surfactant binds to daptomycin and prevents it from inserting into the bacterial membrane, so it can’t exert its effect against pneumonia pathogens. This makes it ineffective for treating pneumonia, despite good activity against other Gram-positive bacteria elsewhere in the body. In contrast, other agents listed have appropriate roles in pneumonia. Linezolid is active against MRSA and can be used for MRSA pneumonia. Ceftriaxone covers common community-acquired pathogens and is a standard option for many pneumonias. Mupirocin is a topical agent used for skin infections and nasal decolonization, not for treating pneumonia.

Daptomycin should not be used for pneumonia because pulmonary surfactant inactivates it. Daptomycin works by binding to Gram-positive bacterial membranes in a calcium-dependent way, forming pores and causing rapid depolarization that kills the bacteria. However, in the lungs, surfactant binds to daptomycin and prevents it from inserting into the bacterial membrane, so it can’t exert its effect against pneumonia pathogens. This makes it ineffective for treating pneumonia, despite good activity against other Gram-positive bacteria elsewhere in the body.

In contrast, other agents listed have appropriate roles in pneumonia. Linezolid is active against MRSA and can be used for MRSA pneumonia. Ceftriaxone covers common community-acquired pathogens and is a standard option for many pneumonias. Mupirocin is a topical agent used for skin infections and nasal decolonization, not for treating pneumonia.