Comparative clinical study of doxycycline and minocycline.

Doxycycline and minocycline were given intravenously to patients with a serious underlying disease who presented a pulmonary infection or a wound infection. Both therapies were easy to administer and well tolerated. However they should not be used in the initial therapy since resistant strains may occur. The clinical and bacteriological effectiveness of doxycycline and minocycline were similar. In pneumococcal pulmonary infections, the rates of favorable clinical response to doxycycline and minocycline were 73% and 76% respectively. In infections caused by bacteroides sp.(mainly infections of wounds), doxycycline or minocycline resulted in a 75% rate of favorable clinical responses and in a 71% rate of favorable bacteriological responses. Adverse side effects were rare and of minor importance with the exception of bacteriological colonization by doxycycline-resistant or minocycline-resistant microorganisms. This complica-tion occurred in 39% of the patients who were treated with these drugs and resulted in clinical superinfection in 8% of the patients.