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Principles of AMT Cheat Sheet by

Antimicrobial therapy (AMT)

Principles for rational prescr­ibing

1. Is an antibiotic indicated?
2. Cultures before admini­stering AB in hospit­alised patients or patients with recurrent infections
3. Choose an approp­riate empiric antibiotic
4. Correct dose and route of admini­str­ation
5. Start AB rapidly in severe infections
6. Practice early and effective source control
7. Evaluate approp­ria­teness everyday

When is an antibiotic indica­ted?

Depend on diagnosis?
> Fever
> Leukoc­ytosis
> Raised inflam­matory markers
> Specific organ dysfun­ction

When is an antibiotic indica­ted?

Antibi­otics Indicated:
P= prophy­lactic treatment
> Prevention of new/re­current infections

E= empirical treatment
> treat for most likely infective organism (no culture results yet)

D= Definitive treatment
> treat w/ AB as per results of microbial culture and sensit­ivity (MCS)

Leuk­ocy­tes­&I­nfl­amm­atory Markers:

White Cell count
Erythr­ocyte sedime­ntation rate
0-22mm/hr (men)
0-29mm/hr (women)
C-reactive protein

Prop­hyl­actic treatm­ent:

Infective endoca­rditis (patients with prosthetic heart valves­/va­lvular disease)
> Dental, oral or URT procedures
> GU surgery / GI procedures
Rheumatic fever (reocc­urr­ence)
Mening­ococcal disease (contacts)
TB (high risk indivi­duals / contacts)
HIV (high risk indivi­duals / contacts)

Empiric antibiotic is indica­ted:

Choose by assessing:
1. Source of infection:
Community acquired Before or less than 48 hours of admission to hospital. Microo­rganism expected? Wild/n­on-­res­istant mo's. 1st line antibi­otics. Less side effects.
Hospital acquired >48 hours after admission or within 30 days of discharge. Microo­rga­nisms expected? Mutated / resistant microo­rga­nisms. Second line antibi­otics. More side-e­ffects.
2. Site of infection:
Peripheral line sepsis­=sk­in/soft tissue. Likely pathogen. Staph. aureus. Coagulase negative staphy­loc­occi, strep. spp.

Cuta­neous Abscess:


Bacterial infection of bone due to contaguous spread from soft tissues, haemat­ogenous seeding or direct inocul­ation.
Common aetiol­ogies
– S aureus. – Coagul­ase­--‐­neg­ative staphy­lococc
– Strept­ococci. - Entero­cocci. - Gram--­‐ne­gative bacilli.
– M tuberc­ulosis. – Fungal infect­ions.

Oste­omy­elitis (cont)

Diagnosis and Treatment

Oste­omy­elitis (cont.)

Diagnosis and treatment notes.

Empiric Treatm­ents:

Most likely pathogen for site of infection
> Gram + cocci:
> Gram - bacilli:
> Gram + and -, anareobes:
Large intestine

Clas­sif­ication of Bacter­ia:

Empiric Treatment: drug distri­but­ion:

Will AB reach site of infection?

Defi­nitive Treatm­ent:

Microbial culture and sensit­ivity results done.
Culture of:
> Urine
> Sputum
> Cerebr­ova­scular fluid
> Nasal secretions
> Wound / throat swab
> Blood

Micr­obial Culture:

Growing microbe to identify the type of bacteria.
Microbial Sensit­ivity:
Identify which antibi­otics inhibits the growth of the microo­rganism

Micr­obial Culture (cont.):

routes of admini­str­ation.

Micr­obial Culture (cont.):

Recomm­ended duration of definitive treatment.

Case study questi­ons:

Ration­alise if an antibiotic is indicated?
What pharma­col­ogical / non-ph­arm­aco­logical treatment would you recommend?
How would you monitor the efficacy and safety of the treatment once initiated?
What is a possible compli­cation of a sore throat? - Otitis media (spread of infection to the middle ear) Meningitis (spread of infection to the lining of brain and spinal canal) Pneumonia (lung infection)

Road Map:



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