Penetration of Various Antibiotics into Sputum

Abstract

Various antibiotics that can be administered orally have been investigated in respect of sputum levels by several authors. Table 1 shows that peak sputum concentrations were five times higher after a single dose of 0.2 g minocycline than after the recommended single dose of 0.1 g doxycycline. During continuous treatment with other drugs in the usual dosages, peak sputum levels were highest with erythromycin, followed by amoxycillin, cefaclor, cefalexin and ampicillin. In relation to the in vitro sensitivity of Haemophilus influenzae to several antibiotics (Table 2), these findings suggest that the antibiotic concentrations reached are not sufficient to eliminate such bacteria from the sputum in all cases, but we know that host defense mechanisms may enhance the antibacterial efficacy of a drug.