Monobactams

GENERAL PRINCIPLES

Aztreonam (1-2 g IV/IM q6-12h) is a monobactam that is only active against aerobic gram-negative bacteria, including P. aeruginosa. It is useful in patients with known serious β-lactam allergy because there is no apparent cross-reactivity. Aztreonam is also available in an inhalational dosage form (75 mg inhaled q8h for 28 d) to improve respiratory symptoms in cystic fibrosis patients infected with P. aeruginosa.