Effects of aztreonam on fecal flora and on vitamin K metabolism

Abstract

The effects of aztreonam on fecal flora and on descarboxy prothrombin (PIVKA-II) in plasma and γ-carboxyglutamic acid (Gla) in urine as an index of vitamin K metabolism were studied in seven children (age range, 2 months to 2 years) with urinary tract infections. Daily doses of aztreonam were 60 to 80 mg/kg. Stool specimens were obtained before the treatment, on days 3 to 5 of aztreonam use, and from 3 to 5 days after the cessation of treatment. The counts of enterobacteria decreased (P < 0.01) and those of streptococci increased (P < 0.05) during aztreonam treatment. The anaerobic organisms, especially bifidobacteria and bacteroides, showed no marked change. PIVKA-II and Gla were investigated before and during the treatment with aztreonam. PIVKA-II was not detected in seven patients before or during aztreonam use. There were no significant differences in the levels of Gla in urine before or during the treatment.