To investigate the or bioavailability of aztreonam (SQ 26,776), we administered single 500-mg doses of this monobactam as an oral solution, as two 250-mg capsules, and as a 3-min intravenous infusion to 15 healthy male subjects at 1-week intervals according to a three-way crossover study design. Serum and urine samples were assayed by microbiological methods. The absolute systemic bioavailability of each orl formulation, defined as the ratio of areas under the serum concentation-time curves after oral and intravenous administation, was less than 1%. Peak serum levels achieved with oral solution, capsule, and intravenous infusion were 0.15, 0.14, and 56.7 g/ml, respectively, and cumulative urinary excretion was 0.7, 0.6, and 68% of the administered dose, respectively. Before each drug administration, subjcts fasted for 8 h. The subjects remained in an upright position (sitti or standing) for at least 2 h after each administration of drug. To promote urine formaton, we also gave 250-ml volumes of tap water to each subject at 1 and 2 h after antibiotic administration. Food and beverages were permitted 4 h after dosing.
Sam__ing fAib for drug amy. Samples of blood for assay of aztreonam were drwn before each drug administration. Blood was sampled at 5, 10, 20, and 30 min and 1, 1.5, 2, 3, 4, 6, 12, and 16 h after intravenous administration of drug and at 10, 20, and 40 min and 1, 1.5, 2, 3, 4, 6, 8, 12, and
