The majority of lower
respiratory tract infections (LRTI) are treated "blindly" because the establishment of an aetiological diagnosis is not possible in most cases. The rational choice of
therapy mainly rests upon the knowledge of the microbiological epidemiology of LRTI, and on the possible host-parasite relationship. In community-acquired
pneumonia, there is general concensus that
penicillin maintains its position as the first
drug of choice, and that
therapy can be changed to
erythromycin or
tetracycline in cases of therapeutic failure. Treatment of
nosocomial pneumonia, and LRTI in immunocompromised patients, calls for
antibiotics with a broader antimicrobial spectrum.
Clindamycin has an antimicrobial spectrum which makes this
antibiotic a possible alternative in community-acquired
pneumonia, and its efficacy in
pneumococcal pneumonia has been documented. However, as first choice
therapy it should be reserved for cases of
penicillin allergy, or cases of strongly suspected
staphylococcal pneumonia. In
aspiration pneumonia--nearly always caused by anaerobic bacteria--
penicillin has long been the preferred
therapy, even in cases with Bacteroides fragilis. However, recent publications have clearly documented that in primary
lung abscess,
clindamycin is superior to
penicillin. These results are especially important since
metronidazole has been shown to be less effective in such cases.