antibiotic matching Flashcards
what is pre test probability used for?
to inform the history and examination, to dictate tests and act as a starting point to match the symptoms with the diagnosis
what are the most common differential diagnoses for urinary infections?
pyelonephritis, catheter associated UTIs, cystitis, prostatitis, renal abscesses
what are the most common differential diagnoses for abdo infections?
dental, abdo, biliary tract infections, H pylori, C difficile, spontaneous bacterial peritonitis, gastroenteritis and appendicitis
what are the most common differential diagnoses for respiratory infections?
ventilator associated, post viral, hospital acquired or community acquired pneumonia or TB
what are the most common differential diagnoses for orthopaedic or skin and soft tissue infections?
cellulitis, orbital cellulitis, osteomyelitis, septic arthritis, infected ulcer, necrotising fasciitis, diabetic foot infection, prosthetic joint infection, pilonidal abscess, fourniers gangrene
what are the most common differential diagnoses for vascular and CNS infection?
infected DVT, endocarditis, mycotic aneurysm, encephalitis, bacterial and TB meningitis, brain abscess, central venous catheter infections
how do you progress from a differential to a working diagnosis?
history, exam, lab and radiological tests, trial without and trial of therapy, pretest probability
what needs to be considered when taking a history?
recent antibiotic use
what cultures can be done?
urine, blood, bacterial (ascitic), abdo fluid, joint fluid, wound swab, sputum, bone sample, biopsy
what is diagnostic iteration?
it is a procedure in which repetition of operations or tests yields results that are successively closer to desired result - gives a high diagnostic probability
what group of ABs includes azithromycin, clarithromycin and erythromycin?
macrolides
what is used in the case of a mild infection ?
amoxicillin
if penicillin allergy then use clarithromycin or doxycycline
in a medium infection what ABs are used?
amoxicillin and clarithromycin
if penicillin allergy - levofloxacin or doxycycline
if there is a high severity infection what ABs are used?
co-amoxiclav IV and clarithromycin
if allergic to penicillin then used levofloxacin PO
what is the common pathogen of post viral pneumonia?
S aureus
what is MRSA resistant to ?
beta lactams
what are the characteristics for amoxicillin?
IV and PO available
can be considered for cystitis and systemic infections
what are the characteristics for flucloxacillin?
IV and PO available
can be considered for systemic infections
unsure around cystitis
what are the characteristics for erythromycin?
IV and PO available
can be considered for systemic infections
unsure around cystitis
what are the characteristics for levofloxacin?
IV and PO available
can be considered for cystitis and systemic infections
what are the characteristics for trimethoprim?
IV and PO available
can be considered for cystitis and systemic infections
what are the characteristics for doxycycline?
IV not available but PO is available. considered for systemic infection but not for cystitis
what are appropriate antibiotics for the gram positives S aureus and strep pneumoniae?
vancomycin or doxycycline
what can amoxicillin be used for?
the gram negative coccus moraxellas catharalis and gram negative rods haemophilus influenzae
what are macrolides appropriate for?
the gram negative rods with no cell wall - chlamydia, legionella and mycoplasma pneumoniaes
in what global challenge situation should microbiology be consulted?
when there are CPEs present - carbapenemase producing enterobacteriacae
what are the three mutations that are challenging in E coli?
penicillinase, CPEs, ESBLs - extended spectrum beta lactamase
what are teicoplanib and vancomycin are what types of AB and what does this imply?
they are both glycopeptide antibiotics and therefore can be interchanged
what are broad spectrum antibiotics?
they are antibiotics or combinations of that provide cover for gram positive, negative and anaerobes such as co-amoxiclav
what are gram positive antibiotics and give five examples?
they are antibiotics that are used to cover gram positive pathogens only teicoplanin/vancomycin amoxicillin/penicillin linezolid macrolides e.g. carithromycin flucloxacillin
what are gram negative antibiotics and gives three examples?
antibiotics that are mostly used to cover gram negative bacteria
gentamicin
ciprofloxacin
aztreonam
what are antibiotics that are commonly used to treat cystitis?
those that are used to treat e. coli nitrofurantoin trimethoprim fosfomycin pivmecillinam cephalexin
