Aztreonam

Indications

Aztreonam is used for: Bone and joint infections, Intra-abdominal infections, Lower respiratory tract infections, Meningitis, Septicaemia, Skin and soft tissue infections, Pelvic infections, Gonorrhoea, Cystitis, Urinary tract infections, Cystic fibrosis

Adult Dose

Adult: IV/IM Gm-ve infections 1-8 g/day in divided doses depending on severity. Max: 8 g/day. UTI 0.5-1 g 8-12 hrly. IM Cystitis; Gonorrhoea 1 g as a single dose.

Child Dose

Child: IV, IM 90–120 mg/kg/day q6–8hr Infants >1 wk: 30 mg/kg every 6 or 8 hr

Renal Dose

Renal impairment CrCl 10-30 mL/min: 1-2 g loading dose, then 50% of usual dosage CrCl <10 mL/min: 1-2 g loading dose, then 25% of usual dosage

Administration

Reconstitution: IM: Reconstitute vial w/ at least 3 mL of sterile water for inj, sterile bacteriostatic water for inj, normal saline, or bacteriostatic NaCl per g of aztreonam; immediately shake vigorously. IV: Bolus inj: Reconstitute vial w/ 6-10 mL of sterile water for inj. Infusion: Reconstitute vial w/ at least 3 mL of sterile water for inj per g of aztreonam; immediately shake vigorously. Then further dilute in an appropriate soln for infusion to a final concentration of <2%.

Contra Indications

Hypersensitivity to aztreonam.

Precautions

History of β-lactam hypersensitivity. Renal and hepatic impairment. Childn. Pregnancy and lactation. Monitoring Parameters Monitor for signs of anaphylaxis during 1st dose; periodic LFT. Consider measuring FEV1 prior to initiation of inhalation therapy. Lactation: Drug is excreted in milk in low concentrations; use not recommended (American Academy of Pediatrics committee states that drug is compatible with nursing)

Pregnancy-Lactation

Pregnancy category: B Lactation: Drug is excreted in milk in low concentrations; use not recommended (American Academy of Pediatrics committee states that drug is compatible with nursing)

Interactions

Concurrent use w/ oral anticoagulants may increase prothrombin time.

Adverse Effects

Side effects of Aztreonam : >10% Injection Pain at injection site (12%; children); (2%; adults) Increase in serum transaminases (4-6%) Neutropenia (3-11%, children); (<1%, adults) 1-10% Rash (4%), Thrombocytopenia (4%, children); (<1% adults), Diarrhea (1%), Nausea (1%), Vomiting (1%), Fever (<1%) < 1% Abnormal taste, Anaphylaxis, Anemia, Angioedema, Aphthous ulcer, Breast tenderness, Bronchospasm, Clostridium difficile-associated diarrhea (CDAD), Confusion, Diplopia, Dizziness, Dsypnea, Electrocardiographic changes (transient), Erythema multiforme, Eosinophilia, Fever, Flushing, Halitosis, Headache, Hepatitis, Hypotension, Insomnia, Jaundice, Leukocytosis, Neutropenia, Pancytopenia, Seizures, Thrombocytopenia, Tinnitus, Tongue numbness, Toxic epidermal necrolysis, Urticaria, Vaginitis, Vertigo, Weakness, Wheezing Potentially Fatal: Clostridium difficile-associated diarrhoea from mild diarrhoea to fatal colitis.

Mechanism of Action

Aztreonam inhibits bacterial cell wall synthesis due to its high affinity for penicillin-binding protein 3 (PBP-3) of gm-ve bacteria. It is highly resistant to hydrolysis by many narrow-spectrum β-lactamases. It is also active against most Enterobacteriaceae (including E. coli, Citrobacter, Enterobacter, Klebsiella, Proteus, Providencia, Salmonella, Serratia, Shigella, Yersinia spp. and Morganella morganii).