Penetration of ofloxacin from blood to sputum.

Serum and sputum concentrations of ofloxacin were measured by a microbiological agar-well diffusion assay in nearly 100 patients after single 400, 600 or 800 mg doses of ofloxacin. All patients were admitted to hospital because of acute purulent exacerbations of chronic respiratory disease, and the concentration studies were performed on the first treatment day while the sputum was still purulent. Both blood and sputum samples were tested at standardised time intervals after dosage, and concentration-time curves were constructed. Cmax values in serum and sputum were 3.7 and 2.7 mg/L after 400 mg ofloxacin, 7.1 and 6.1 mg/L after 600 mg and 8.8 and 6.3 mg/L after 800 mg. Penetration from blood to sputum, as judged from ratio of AUC values for sputum and serum, varied from 78 to 103%.