Amoxycillin levels in sputum, serum, and saliva

Abstract

The levels of amoxycillin in sputum, saliva and serum from 22 patients were estimated. Fifteen patients had pneumonia and 7 had acute exacerbations of chronic bronchitis. The drug was given orally in a dose of 500 mg 4 times daily. There was considerable variation, in the levels in specimens from different patients. The mean sputum levels 2 to 3 hr and 6 hr after the dose were 0.52 and 0.53 g/ml respectively. The mean 2 hr saliva level was 0.32 μg/ml. The mean serum levels 2 and 6 hr after the test dose were 11.0 and 3.5 μg/ml respectively. The higher levels of amoxycillin were usually associated with the presence of more pus in the sputum. The mean levels of amoxycillin were significantly greater than those found in a previous study after the same dose of ampicillin. Clinical response to treatment occurred more rapidly in those patients with sputum levels of 0.25 μg amoxycillin per ml or above than is those with lower levels. The time taken to clear potential pathogens from the sputum was related to the pathogen rather than to the amoxycillin level, Haemophilus influenzae persisting longer than Streptococcus pneumoniae.