To the Editor.
—In the February issue (Arch Intern Med127:217-227, 1971) a discussion of the medical therapy for lung abscesses included reference to a substantial proportion of patients who were treated with a combination of penicillin and tetracycline. Recently, however, it has become apparent that such combinations are actually inferior to an adequate dose of the more effective agent.1,2 Tetracycline is currently thought to diminish the bactericidal activity of penicillin, both in vitro and in vivo. This important point is not mentioned in the discussion and may lead the reader to falsely assume that this specific combination is more effective than the single administration of penicillin.References