antibioticsbooks

130 PART 2 Antibacterial Drugs
Adverse Effects
Daptomycin has effects on skeletal muscle that
can manifest as muscle pain or weakness, or possibly
rhabdomyolysis. To monitor for this effect,
creatine kinase (CK) concentrations should be
checked weekly while on therapy. This toxicity can
be decreased by administering the drug no more
than once daily and by adjusting the interval in
renal dysfunction. Drug fever is also a possibility.
Eosinophilic pneumonia has been reported in
patients on daptomycin therapy.
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Important Facts
• Daptomycin is active against many resistant
Gram-positive organisms, including VRE and
MRSA. It has been proven effective in staphylococcal
endocarditis (specifically right-sided
endocarditis), an indication that few antibiotics
have.
• Resistance to daptomycin is very rare, but it is
reported occasionally. Before using daptomycin
for your patient, ensure that the lab tests the
isolate for daptomycin susceptibility. Because a
standard MIC for resistance has not yet been
defined, labs may report isolates as “nonsusceptible”
or, worse, not report them at all if they
do not fall into the susceptible range. Ask your
lab for specifics on its procedures.
• Though it penetrates lung tissue very well,
daptomycin cannot be used to treat pneumonia.
Human pulmonary surfactant binds to
daptomycin, rendering it inactive. Early clinical
trials showed poor outcomes in daptomycintreated
pneumonia patients.