Clinical evaluation of the effect of cefotaxime in senile pneumonia caused by gram-positive and gram-negative bacteria.

66 patients with predominantly community-acquired pneumonia were treated with cefotaxime. The group consisted of 45 males and 21 females, aged 56 to 90 years, 43 of the patients belonging to the age groups 65-80 years. Streptococcus pneumoniae was isolated in 21 of the 34 patients with gram-positive pneumonia, Staphylococcus aureus in six, Staphylococcus epidermidis in five and Streptococcus faecalis in two. Klebsiella pneumoniae was the predominant pathogen in gram-negative pneumonia (eight patients), followed by Enterobacter (n = 6), Pseudomonas aeruginosa (n = 5), Haemophilus influenzae (n = 4), Escherichia coli (n = 3), Serratia marcescens and Citrobacter (two cases each). The in vitro activity of cefotaxime against the isolates was compared to the activity of other beta-lactam antibiotics. Characteristically, the classical signs and symptoms of pneumonia were absent or discrete in some of the elderly patients. There was a delayed clearance of pulmonary infiltrates. 55 of 66 patients responded to cefotaxime within four weeks of treatment; the symptoms were aggravated or remained unchanged in seven patients. Patients with a delayed clinical response displayed decreased peripheral lymphocyte counts and T cell functions in PHA stimulation tests, as well as low immunoglobulin levels. A combination of cefotaxime and gamma-venin cleared the symptoms in some of these patients.