Monobactam (monocyclic bacterially derived beta-lactam)
Gram-negative bacteria: Pseudomonas aeruginosa, Enterobacteriaceae, Escherichia coli, Haemophilus spp., Proteus mirabilis, Proteus spp., Providencia spp., Salmonella spp., Serratia spp., Shigella spp., and Klebsiella spp.
Interferes with bactericidal cell wall synthesis by binding to and inactivating penicillin-binding-proteins. This binding causes the formation of elongation or bacterial filamentation resulting in cell lysis and cell death.
Aztreonam produces time-dependent killing.
Cmax: 255mg/L (after 2g IV dose); Half-life: 1.7 to 2 hours; Protein binding: 56 to 72%; Volume of distribution: 0.06 L/kg
Dermatologic: rash (rare)
Gastrointestinal: nausea, vomiting, diarrhea, pseudomembranous colitis (rare), increased liver enzymes, pancytopenia and neutropenia
Dermatologic: painful, injection-site reactions
IV: 500mg, 1gram, 2gram vials for injection
Adult dose: IV/IM: 1-2 g q8h
Systemic or life-threatening infections: 2 g IV/IM q6h
Severe systemic infections: 2g IV q6-8h, maximum of 8g per day
Urinary tract infection: 0.5-1g IV/IM q8-12h
Infants less than 1 week of age: 30 mg/kg q12h
Infants 1 to 4 weeks of age: 30 mg/kg q8h
Infants greater than 1 month of age: 30 mg/kg q6-8h
Renal failure: CrCl 10-30 mL/min: Normal loading dose, followed by a 50% reduction of the loading dose given at the same frequency of normal patients
CrCl less than 10 mL/min: Normal loading dose, followed by a 75% reduction of the loading dose given at the same frequency of normal patients
Hepatic failure: No dosing changes recommended at this time.
CVVH (Continuous venovenous hemofiltration): 1-2g IV q12h
CVVHD (Continuous venovenous hemodialysis): 2g IV q12h
CVVHDF (Continuous venovenous hemodiafiltration) 2g IV q12h
Note: CVVH is mainly for fluid removal alone. Many institutions will employ more CVVHD or CVVHDF which combine dialysis with fluid removal.
Precautions: extremely low birth-weight infants or infants with congenital/acquired arginase deficiency; use aztreonam arginate with caution
Warnings: Although cross-reactivity with penicillins and cephalosporins is exceedingly rare, ceftazidime and aztreonam share a common side-chain. For this reason, use caution in administering aztreonam in patients who endorse a ceftazidime allergy.
No clinically significant drug interactions have been identified.
Category B: No evidence of risk in humans but studies inadequate.
Therapeutic: Culture and sensitivities, serum levels, signs and symptoms of infection (e.g. fever, WBC)