aztreonam

aztreonam is a synthetic monobactam antibiotic used primarily to treat infections caused by susceptible aerobic gram-negative bacteria. It is marketed under brand names such as Azactam and Cayston and is notable for its stability against many beta-lactamase enzymes. Its development by researchers at Squibb Institute for Medical Research provided a targeted therapeutic option with a narrow spectrum of activity and a favorable safety profile for patients with penicillin allergy.

Medical uses

Aztreonam is indicated for the treatment of a variety of infections due to susceptible organisms, including complicated and uncomplicated urinary tract infections, lower respiratory tract infections, septicemia, skin and skin-structure infections, intra-abdominal infections, and gynecologic infections. It is particularly valuable in treating infections caused by pathogens like Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis. The Food and Drug Administration has also approved an inhaled formulation for the management of cystic fibrosis in patients colonized with Pseudomonas aeruginosa. Clinical use is guided by susceptibility testing from institutions like the Clinical and Laboratory Standards Institute.

Adverse effects

The most common adverse reactions associated with intravenous aztreonam administration include reactions at the injection site, rash, diarrhea, nausea, and vomiting. Less frequent but more serious effects can involve hepatotoxicity, blood dyscrasias such as neutropenia, and seizures. The inhaled formulation can cause bronchospasm, cough, nasal congestion, and wheezing. While cross-reactivity with other beta-lactam antibiotics is rare, caution is advised in patients with a history of severe IgE-mediated reactions to agents like penicillin or cephalosporin.

Pharmacology

Aztreonam exerts its bactericidal effect by binding to specific penicillin-binding proteins (PBPs), particularly PBP-3, in the bacterial cell wall, which inhibits the final step of peptidoglycan synthesis. Its structure, featuring a monocyclic beta-lactam ring, confers stability against many plasmid- and chromosomally-mediated beta-lactamase enzymes, including those produced by members of the Enterobacteriaceae. Pharmacokinetically, it achieves good penetration into tissues and body fluids, including cerebrospinal fluid in the setting of inflamed meninges. Elimination is primarily via glomerular filtration, with dosage adjustments required in patients with impaired renal function.

History

The discovery of aztreonam originated from the screening of bacterial metabolites, leading to the isolation of the basic monobactam nucleus, sulfazecin, from strains of Chromobacterium violaceum and related bacteria. This work was pioneered by a team at the Squibb Institute for Medical Research in the late 1970s, with key contributions from scientists like R. B. Sykes and R. N. Swanson. The compound, designated SQ 26,776, underwent extensive clinical development, receiving its first approval from the Food and Drug Administration in 1986. Its development represented a significant achievement in medicinal chemistry, creating a class of antibiotics with targeted activity.

Society and culture

Aztreonam is available globally under various brand names and is included on the World Health Organization's List of Essential Medicines. Its role in treating multidrug-resistant infections has been highlighted in guidelines from organizations like the Infectious Diseases Society of America. The drug has been the subject of patent litigation in jurisdictions such as the United States Court of Appeals for the Federal Circuit. Furthermore, its inhaled formulation represents an important advance in the management of chronic Pseudomonas aeruginosa infection in patients with cystic fibrosis, supported by patient advocacy groups like the Cystic Fibrosis Foundation.

Category:World Health Organization essential medicines Category:Antibiotics