Category Myths & Misconceptions

Extrapolating antibiotic susceptibility for streptococci including the pneumococcus

This posting concerns betahaemolytic species of streptococci including S. pyogenes (Lancefield group A strep), S. agalactiae ((group B strep), S. dysgalactiae group (betahaemolytic large colony, groups C or G) (several species included) which are usually associated with pyogenic infection, especially of skin and soft tissue.   S. pneumoniae (the pneumococcus ) is also considered.  A key misunderstanding about […]

Cranberry for prevention and treatment of UTI- placebo or better?

Cranberry juice or cranberry capsules are often recommended for both prophylaxis and treatment of UTIs. As cranberry is associated with only mild side effects and is easy available it seems like it would be a good option, but what evidence is there that shows that it is effective?

Relative mortality risk from antibiotic use compared

Much time is spent discussing the development of antimicrobial resistance and changes to the microbiome but perhaps should we should also focus on the potential for patient mortality.  Based on best current estimates, trimethoprim, macrolides and quinolones may be less safe than chloramphenicol in certain patient populations. A future posting will provide a practical approach to the […]

Let’s stop using antibiotics for uncomplicated diverticulitis

Guest posting : Dr Daniel Isacson, local GP (ex Swedish researcher) The evidence is out and there is no proven benefit in recovery or complication rates in treating these patients with or without antibiotics, but still many GPs and surgeons prefer to use antibiotics. How do we get the word across? 

Recurrent urinary tract infection in women – are antibiotics the answer?

What is the evidence? This interesting paper from 2010 discusses the natural history of UTI in women and distinguishes two conditions – the ‘urethral’ (or ‘dysuria/frequency’) syndrome’ (US) which affects a proportion of women with recurrent symptoms and many courses of treatment.  It is known that US is a self-limited condition in a majority of patients.  Some women are said to […]

Is penicillin enough for aspiration pneumonia?

There has been quite a tradition for including Gram negative anaerobic cover for patients suspected to have aspiration pneumonia. There are virtually no randomised trials that directly address the issue with nearly all such trials including agents that have Gram negative anaerobic cover across all treatment arms.   One exception was a small trial from 1997 in a paediatric […]

Is vitamin C3 (ceftriaxone) a good anxiolytic for prescribers faced with diagnostic uncertainty ?

The adult presented with 1 week of non-productive cough (yes, a good history was taken), and had no signs of sepsis other than fever. CRP moderately raised, CXR normal. The clinician documented a vague differential diagnosis and started vitamin C3 (ceftriaxone). 

Clostridium difficile – misconceptions about testing

Confine testing to symptomatic patients. Testing of patients with formed stools may generate false positives due to asymptomatic carriage of toxigenic strains. An unfortunate side effect of multiplex PCR stool assays, are that tests that are inappropriate to the clinical circumstance may be performed, generating false positives. Also test at-risk (i.e. antibiotic or ppi-exposed) symptomatic […]

Bronchiectasis and goals of antibiotic treatment – thinking it through

The setting – patients with bronchiectasis (including those with cystic fibrosis) have impaired respiratory secretion clearance and a vastly different lower respiratory flora (microbiome) than patients with normal lungs.  They are frequently colonised with conventional respiratory species such as Haemophilus influenzae and Moraxella catarrhalis,  Staphylococcus aureus,  a diverse range of Gram negative bacteria and even fungi. Colonisation/infection with non-tuberculous […]

Tazocin misconceptions: misuse in community-acquired pneumonia – spectrum too broad

Piperacillin+tazobactam (Tazocin) is an important broad spectrum antibiotic that is still active in most Australian settings against a wide range of Gram negatives (including Pseudomonas) , Gram positives (excluding MRSA and VRE) and nearly all anaerobic bacteria. It comes into great demand for management of a range of healthcare-associated infections, especially in ICU. Its use […]