Aztreonam

General

• Type: Monobactam
• Dosage forms: IM; IV
• Common Trade Names: Azactam

Other

• Antimicrobial activity more closely resembles AG's (only active against gram -)
  • Enterobacter, pseudomonas, H. influenzae, gonococci
  • Little allergic cross-reactivity with B-lactam antibiotics

Adult Dosing

General (Moderate Severe)

• 1-2g IM/IV q8-12h
• Max: 8g/day

General (Severe)

• 2g IM/IV q6-8h
• Max: 8g/day

Pediatric Dosing

General (Neonates)

• <7 days old
  • <2000g
    • 60mg/kg/day IV divided q12h
    • First ED Dose: 30mg/kg x 1
  • >2000g
    • 90mg/kg/day IV divided q8
    • First ED Dose: 30mg/kg x 1
• 7 days - 1 month
  • <1200g
    • 60mg/kg/day IV divided q12h
    • First ED Dose: 30mg/kg x 1
  • 1200-2000g
    • 90mg/kg/day IV divided q8
    • First ED Dose: 30mg/kg x 1
  • >2000g
    • 120mg/kg/day IV divided q6
    • First ED Dose: 30mg/kg x 1

General (1 Month - 9 Months)

• General
  • 90-120mg/kg/day IV divided q6-8h
  • First ED Dose: 40mg/kg x 1
• Respiratory Infections in Cystic Fibrosis
  • 200mg/kg/day IV divided q6h
  • First ED Dose: 40mg/kg x 1
  • Max: 8g/day

General >9 Months)

• 90-120mg/kg/day IV divided q6-8
• First ED Dose: 40mg/kg x 1

Special Populations

• Pregnancy Rating: B
• Lactation: Safe
• Renal
  • Adult
    • CrCl 10-30: 1-2g x1, then decrease dose 50%
    • CrCl <10: give usual dose x1, then decrease dose 75%
    • Hemodialysis: give 12.5% of initial dose as supplement
    • Peritoneal dialysis: no supplement
  • Pediatric
    • CrCl 10-30: decrease dose 50%
    • CrCl <10: decrease dose 75%
    • Hemodialysis: give supplement
    • Peritoneal dialysis: no supplement
• Hepatic (Adult & Pediatric)
  • caution advised, but not defined

Contraindications

• Allergy to class/drug

Adverse Drug Reactions

Serious

• Anaphylaxis
• Allergic Reaction
• Toxic Epidermal Necrolysis
• Seizures
• C diff
• Hepatitis
• Neutropenia
• Thrombocytopenia
• Anemia

Common

• Phlebitis
• Injection site reaction
• Diarrhea
• Nausea/vomiting
• Rash
• Transaminitis
• Elevated creatinine
• Eosinophilia

Pharmacology

• Half-life: 1.7h (4.7-6h ESRD)
• Metabolism: CYP450, minimal liver
• Excretion: Urine
• Mechanism of Action: Bactericidal; inhibits cell wall synthesis

Antibacterial Spectra

Group	Organism	Sensitivity
Gram Positive	Strep. Group A, B, C, G	R
	Strep. Pneumoniae	R
	Viridans strep	R
	Strep. anginosus gp	R
	Enterococcus faecalis	R
	Enterococcus faecium	R
	MSSA	R
	MRSA	R
	CA-MRSA	R
	Staph. Epidermidis	R
	C. jeikeium	R
	L. monocytogenes	R
Gram Negatives	N. gonorrhoeae	S
	N. meningitidis	S
	Moraxella catarrhalis	S
	H. influenzae	S
	E. coli	S
	Klebsiella sp	S
	E. coli/Klebsiella ESBL+	R
	E coli/Klebsiella KPC+	R
	Enterobacter sp, AmpC neg	S
	Enterobacter sp, AmpC pos	S
	Serratia sp	S
	Serratia marcescens	X1
	Salmonella sp	X1
	Shigella sp	S
	Proteus mirabilis	S
	Proteus vulgaris	S
	Providencia sp.	S
	Morganella sp.	S
	Citrobacter freundii	S
	Citrobacter diversus	S
	Citrobacter sp.	S
	Aeromonas sp	S
	Acinetobacter sp.	R
	Pseudomonas aeruginosa	S
	Burkholderia cepacia	R
	Stenotrophomonas maltophilia	R
	Yersinia enterocolitica	S
	Francisella tularensis	X1
	Brucella sp.	X1
	Legionella sp.	R
	Pasteurella multocida	S
	Haemophilus ducreyi	X1
	Vibrio vulnificus	X1
Misc	Chlamydophila sp	R
	Mycoplasm pneumoniae	R
	Rickettsia sp	X1
	Mycobacterium avium	X1
Anaerobes	Actinomyces	R
	Bacteroides fragilis	R
	Prevotella melaninogenica	R
	Clostridium difficile	R
	Clostridium (not difficile)	R
	Fusobacterium necrophorum	X1
	Peptostreptococcus sp.	R

Key

• S susceptible/sensitive (usually)
• I intermediate (variably susceptible/resistant)
• R resistant (or not effective clinically)
• S+ synergistic with cell wall antibiotics
• U sensitive for UTI only (non systemic infection)
• X1 no data
• X2 active in vitro, but not used clinically
• X3 active in vitro, but not clinically effective for Group A strep pharyngitis or infections due to E. faecalis
• X4 active in vitro, but not clinically effective for strep pneumonia

See Also

• Antibiotics (Main)

References

• Epocrates

References

Authors

Ross Donaldson