Ceftriaxone (a third generation cephalosporin-TGC)  remains an overused agent in some of our (HNELHD) facilities.  We aim to keep usage below 20 defined daily doses per 1000 patient-days (as is done at John Hunter Hospital for instance) to prevent adverse ecological impacts on resistance – increases in MRSA, VRE, multi-resistant Gram negatives and C. difficile are all associated with high TGC usage.  Here are some pointers to situations where better alternatives to ceftriaxone exist (given our relatively low local levels of bacterial resistance):

By syndrome:

Respiratory tract

• Acute bronchitis : avoid antibiotics
• Acute exacerbation of COPD:  mostly triggered by antecedent viral infection; if antibiotics indicated , use amoxycillin or doxycycline for short (3 day) course
• Aspiration pneumonia: if antibiotics indicated, use benzylpenicillin + /- metronidazole . See also this discussion.
• Community-acquired pneumonia: see HNE Guideline or consult HNE mobile guideline APP   ;  for admitted cases, benzylpenicillin is the mainstay rather than ceftriaxone which is reserved for penicillin allergic patients.

GIT/ Abdomen

• Diverticulitis: mild/moderate – antibiotics unnecessary – now two RCTS have been conducted on this-  more information in a future posting!
• Cholangitis or cholecystitis – use ampicillin+gentamicin IV as per Therapeutic Guidelines, Australia. Ceftriaxone only for penicillin allergic patients.
• Appendicitis: ampicillin+gentamicin+ metronidazole (majority of patients who presented early do not require prolonged post operative treatment)
• Post perforation surgical patient: ampicillin+gentamicin+ metronidazole (provided source control achieved, short course (4 days) treatment adequate – see this paper and discussion.  Cefazolin+gentamicin otherwise for pen-allergic patients.

Skin/soft tissue

Infections usually due to Gram positive pathogens (staph and strep) and empirical use of ceftriaxone NOT appropriate. Chronic ulcers colonised with Gram negatives do not require treatment targeting those organisms.

Urinary tract

• Positive urine culture result with Gram negative : always consider asymptomatic bacteriuria and avoid antibiotics- does patient actually have symptoms ? Why was the urine collected?
• Uncomplicated UTI – no signs of systemic sepsis: avoid antibiotics if possible. See this recent discussion
• Complicated UTI – pyelonephritis and/or systemic sepsis/bacteraemia : ampicillin+gentamicin OR gentamicin alone

Surgical prophylaxis

There are very few situations where ceftriaxone is indicated. For most operation types, cephazolin is preferred if patient not carrying MRSA. See the HNE LHD guidelines on this blog.

By bug:

Gram positive bacteria

• Staphylococcus aureus – methicillin susceptible – use di/flucloxaxillin
• MRSA – use non betalactam – vancomycin for sepsis/bacteraemia
• Streptococcus pneumoniae – use amoxycillin or benzylpenicillin unless treating acute meningitis
• Beta-haemolytic streptococci (eg S. pyogenes) use penicillin or di/flucloxacillin
• Enterococcus species – resistant to all cephalosporins

Gram negatives

Confine ceftriaxone use to situations where resistance demonstrated to first line agents in a pathogen isolated from a significant clinical site (eg. blood or other sterile site culture).

• Meningococcal sepsis and meningitis; when infection proven, always switch the non-allergic patient to benzylpenicillin and limit duration of treatment to 3-5 days total.