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

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).