Doxycycline and minocycline in the treatment of respiratory infections: a double-blind comparative clinical, microbiological and pharmacokinetic study

Abstract

A group of 41 patients, all admitted to hospital because of acute purulent exacerbations of chronic respiratory disease, were treated with either doxycycline or minocycline in a double-blind randomized study. Drug dosage was one 100 mg capsule twice daily for seven days. Bacteriological and clinical assessment before and immediately after treatment showed no significant differences between the doxycycline and the minocycline groups, nor did further evaluation after seven days follow-up. Pharmacokinetic studies showed that the Cmax and 0-11 h AUC values in blood were higher for doxycycline, whereas the sputum Cmax was, on average, higher for minocycline because of the greater penetration of the latter. The MIC values for the two antibiotics differed slightly, usually, but not always, in favour of minocycline. Problems were experienced with both agents in the eradication of Haemophilus influenzae. The net clinical results with the two drugs were identical.

Penetration of Minocycline Hydrochloride into Lung Tissue and Sputum

“…The concentration of MINO in sputum was nearly 2-fold that of an oral administration at the same dose [10][11][12][13]. The above findings also suggest the clinical efficacy of MINO.…”

Minocycline for the Treatment of Multidrug and Extensively Drug-Resistant A. baumannii: A Review

“…Receipt of a 200-mg one-time intravenous dose has demonstrated peak serum concentrations ranging from 3 to 8.75 µg/mL and trough concentrations from 0.6 to 1.9 µg/mL [21, 33, 34]. After multiple oral doses of 100 mg every 12 h, serum concentrations have ranged from approximately 0.7 to 3.9 µg/mL [21, 34, 35]. Similarly, data reported in the package insert for intravenous minocycline state peak and trough concentrations of 2.52–6.63 and 0.82–2.64 µg/mL, respectively [36].…”

Penetration of minocycline into lung tissues.

“…Measurement of antibiotic concentrations in lung tissues represents a more rational approach to establishing therapeutic levels, although the assays are usually performed on healthy tissue and the values obtained do not necessarily reflect the situation in infected areas (Dureux et al, 1982). The bronchial secretion (sputum)/plasma concentration ratios of minocycline reported in the literature vary between 0.3 and 0.9 (Brogan etal., 1977;Maesen et al, 1989) or between 0.83 and 2.18 (Clauzel etal., 1978). Our results show that when bronchial mucus is collected in situ the amount of antibiotic it contains is much higher: the mean mucus/plasma drug concentration ratios found in our study were 3.06 ± 1.99 for mucus collected by catheterization from the principal and segmental bronchi (n = 5), 1.99 ± 1.80 for mucus collected from segmental and alveolar bronchi proximal to the tumoral obstruction (n = 13), and 5.16 ± 3.26 for mucus collected from bronchi distal to the obstruction (n = 10).…”

“…However, global concentrations in lung tissue were measured by McDonald et al (1973) in three patients and by Naline et al (1991) in 14 patients. These two studies showed, that unlike the concentrations obtained in bronchial secretions, minocycline concentrations in lung tissue were high, with a mean lung tissue/plasma drug concentration ratio of 3.17 ± 1.53, as compared with a sputum/plasma drug concentration ratio varying between 0.3 and 2.8 (Brogan et al, 1977;Clauzel et al, 1978;Maesen et al, 1989).…”

“…The penetration of minocycline into the lower respiratory tract has hitherto been evaluated by measuring concentrations of this antibiotic in bronchial secretions obtained by expectoration (sputum) (Brogan et al, 1977;Clauzel et al, 1978;Maesen et al, 1989). However, global concentrations in lung tissue were measured by McDonald et al (1973) in three patients and by Naline et al (1991) in 14 patients.…”