Aztreonam  (PDF Version)

 

Antibiotic Class:

Monobactam (monocyclic bacterially derived beta-lactam)

 

Antimicrobial Spectrum:

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.

 

Mechanism of Action:

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.

 

Pharmacodynamics:

Aztreonam produces time-dependent killing.

 

Pharmacokinetics:

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

 

Adverse Effects:

Dermatologic: rash (rare)

Gastrointestinal: nausea, vomiting, diarrhea, pseudomembranous colitis (rare), increased liver enzymes, pancytopenia and neutropenia

Dermatologic: painful, injection-site reactions

 

Dosage:

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

 

Pediatric dose:

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

 

Disease state based dosing:

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.

 

Dosing during Continuous Renal Replacement Therapy

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.

 

Contraindications/Warnings/Precautions:

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.

 

Drug Interactions:

No clinically significant drug interactions have been identified.

 

Pregnancy:

Category B: No evidence of risk in humans but studies inadequate.

 

Monitoring Requirements:

Therapeutic:  Culture and sensitivities, serum levels, signs and symptoms of infection (e.g. fever, WBC)

 

Brand names/Manufacturer: