Doxycycline:

• excellent activity against most CAP pathogens, including S. pneumoniae (increasing resistance), H. influenzae, M. catarrhalis, S. aureus, including MRSA, M. pneumoniae, C. pneumoniae, and Legionella spp.

• less doxycycline resistance than macrolide resistance in S. pneumoniae

• has not been associated with causing an increase in penicillin resistance among S. pneumoniae (macrolides have)

• excellent pharmacokinetics/dynamics (high serum and lung levels, concentration-dependent killing)

• less expensive than newer macrolides.