[Tetracycline levels in the sputum in chronic obstructive bronchitis (author's transl)].

After 3 control days, the tetracycline concentration in the sputum of 34 patients was measured daily on 7 days during treatment with the antibiotic. 14 patients took tetracycline (Hostacyclin) in normal doses (2X500 mg or 2X1000 mg) by mouth. 20 patients received rolitetracycline (Reverin) 2X275 mg i.v. daily. With considerable individual fluctuations, sputum concentrations were attained in all series ranging from 1.5 to 2.0 microgram/ml after intravenous administration and from 1.1 to 1.6 microgram/ml after oral dosage. The higher dosage administered orally had no greater influence on the sputum concentration. In each case, sputum levels were attained which lie above the necessary minimum concentrations (0.5 microgram/ml).