Comparative in vitro study of SQ26,776

Aztreonam (30 mg/kg) was administered intravenously every 12 h during week 1 and every 8 h during weeks 2 to 4 of life to 26 low-birth-weight (less than 2,000 g) infants, and plasma concentration-time curves were measured on two occasions. The pharmacokinetics were described equally well by one-compartment and noncompartment models, and the values on day 1 were similar to those measured during the steady state on days 3 to 6. The mean peak plasma concentrations at completion of the 10-min infusion were from 65 to 83 micrograms/ml, the higher concentrations being seen in the larger infants. The half-lives of aztreonam ranged from 5.4 to 8.6 h and did not change significantly with birth weight. The median peak and trough plasma bactericidal titer against a strain of Escherichia coli (MBC, 10 micrograms/ml) was 1:16. Against a strain of Pseudomonas aeruginosa (MBC, 16 micrograms/ml), the median peak and trough bactericidal titers were 1:8 to 1:16 and 1:4, respectively. The urinary concentrations of aztreonam on day 1 of therapy were from 24 to 460.7 micrograms/ml (mean +/- 1 standard deviation, 254 +/- 113 micrograms/ml).

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

Pharmacokinetics and plasma bactericidal activity of aztreonam in low-birth-weight infants

Likitnukul¹,

McCracken²,

Threlkeld³

et al. 1987

“…Aztreonam, a monobactam (17), has excellent activity against aerobic gram-negative bacteria, especially Enterobacteriaceae (4,16) and Pseudomonas aeruginosa (2,9). Because of its lack of activity against gram-positive and anaerobic organisms, it will likely be used with other agents in the initial therapy of serious infections in appropriate pediatric patients, such as newborns and immunocompromised and post-surgical patients.…”

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confidence: 99%

In vitro antimicrobial activity of aztreonam alone and in combination against bacterial isolates from pediatric patients

Stutman¹,

Welch²,

Scribner³

et al. 1984

“…These changes are of particular interest in patients with hematological malignancies, since gut bacteria are often the cause of serious infection in these patients (3,6). Aztreonam (SQ 26,776, formerly azthreonam) is a synthetic monobactam antibiotic with broad in vitro activity against aerobic (or facultatively anaerobic) gram-negative bacilli (7). Strict anaerobes often demonstrate resistance to the drug.…”

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confidence: 99%

Effect of aztreonam on throat and stool flora of cancer patients

Jones¹,

Bodey²,

Swabb³

et al. 1984

Self Cite

Eighteen patients with hematological malignancies received aztreonam in one of two dosing regimens, 1 or 2 g every 8 h for a total of 7 to 9 days. Throat and stool cultures were obtained before and during treatment with aztreonam. Aztreonam had little effect on the predominant throat flora. In contrast, facultatively anaerobic gram-negative bacilli were markedly decreased in stools during the administration of aztreonam. Strict anaerobes in the stool were variably affected by aztreonam.Broad-spectrum antibiotics cause marked changes in gastrointestinal microbial flora (2). These changes are of particular interest in patients with hematological malignancies, since gut bacteria are often the cause of serious infection in these patients (3,6). Aztreonam (SQ 26,776, formerly azthreonam) is a synthetic monobactam antibiotic with broad in vitro activity against aerobic (or facultatively anaerobic) gram-negative bacilli (7). Strict anaerobes often demonstrate resistance to the drug. This study evaluated serial throat and stool cultures in cancer patients receiving aztreonam.Eighteen patients with hematological malignancies were studied. These patients received intravenous aztreonam instead of routine prophylactic antibiotics during the first week of their admission to a laminar-flow unit for the administration of cancer chemotherapy. Informed written consent was obtained from all patients. Patients with known allergies to penicillins or cephalosporins were not eligible for the study. Patients' ages ranged from 16 to 65 years (mean, 48 years). The following laboratory values were required for entry into the study: serum creatinine <1.3 mg/dl, serum glutamic oxaloacetic transaminase <100 U/ml, and serum bilirubin <1.5 mg/dl. There were no changes in these laboratory values during aztreonam use.Two dosage schedules were studied in these patients. One group of 9 patients received 1 g of aztreonam every 8 h for 7 to 9 days. Subsequently, another group of 9 patients received 2 g every 8 h for 7 to 9 days. The drug was administered in 50 ml of 5% dextrose solution over 30 min.Two throat and two stool specimens were obtained for culture from each patient within the 4 days before aztreonam was started. Follow-up throat and stool cultures were collected twice, between days 3 and 5 and between days 7 and 9 of the aztreonam regimen.Stool specimens were collected and placed immediately in a BBL GasPak Jar (BBL Microbiology Systems, Cockeysville, Md.). The specimens were inoculated directly onto 5% sheep blood agar (Remel, Lenexa, Kans.), LBS agar (BBL), Columbia CNA agar (Remel), Tergitol 7 agar H (Difco Laboratories, Detroit, Mich.), C. difficile isolation medium (Remel), Sabouraud dextrose agar (BBL) with gentamicin added, and thioglycolate broth (BBL). All cultures were incubated aerobically at 37°C, except for Lactobacillus and Clostridium difficile cultures, which were incubated anaerobically at 37°C. * Corresponding author.Stool (5 g) was homogenized in 245 ml of sterile isotonic saline. Dilutions of 10-1, 10-3, 10-5, 10-6, a...