Infectious and antimicrobial stew Flashcards
therapeutics
What is antimicrobial stewardship
Promoting appropriate use of antibiotics and combatting antibiotic resistance.
What is “start smart antimicrobial stew” ?
1) Evidence of infection: history, symptoms, physcial exam, test results.
2) Asses: evidence of infection, patient risk
3) Investigate: cultures. lab tests, imaging
4) Taking into consideration: Allergies etc
5) Document: treatment regimen and plan and review dates.
should be done within 48-72 hrs
evidence, asses, investigate, prescribe, document.
What is “cares” antimicrobial steward ship ?
cease
amend
refer
extend
switch
this is for prescription reviews
When should surgical prophylaxis be done before starting surgery procedure ?
within 1 hour before the start of the procedure
normally one dose
but can be more for longer porcedures.
common interactions
Ciprofloxacin and NSAIDS: seizures
ciprofloxacin and methotrexate: toxicity
methotrexate and penicillin: toxicity
warfarin and ciprofloxacin: anticoag effect
macrolides and diuretics: hypokalaemia
sepsis signs adults:
Slurred speech
Extreme shivering
Passed no urine in a day
Severe breathlessness
Illness
Skin discolour
sepsis signs children:
-breathing fast
-convulsions
-bluish pale looking
- rash
-lethargic
- cold
General symptoms of infection
fever
chills and sweats
cough
sore throat
shortness of breath
nasal congestion
diarrhoea
vomit
headache
temperature
local symptoms of infection
uti: pain/burning when urinating
pneumoia: coughing and chest pain
infected cut: redness/pus.
example of broad spectrum antibiotics
doxycycline
Amoxicillin/clavulanic acid
azithromycin
piperacillin/tazobactam
what type of bacteria causes skin infection
staphylococcus aureus
- so can be treated with flucloxacillin
what type of bacteria causes GI infection
anaerobic bacteria
- metronidazole can be used in combo with other broad spectrum antibiotics.
What is the “then focus” bit
1) take samples for culture
2) give appropriate empirical treatment
3) receive culture results
4) change treatment as per culture and sensitivity report (focus)
what are the 5 antimicrobial prescribing decisions
1) stop- if no longer signs or symptoms
2) switch- IV to oral
3)change- ideally change to narrow spectrum
4) continue- document next review or stop date
5)OPAT (outpatient parenteral antibiotic therapy)
what does “I” mean in a S/R sensitivity report
Intermediate
falls between sensitive and resistance
what is used to treat endocarditis
penicillin and gentamicin
- penicillin induces cell wall damage, causing permeability of enterococci to aminoglycosides to increase, facilitating gentamicin to get to the target site.
example of an antagonistic combo that should not be given together
erythromycin and clindamycin
- as they both bind to the same sub unit of bacterial ribosome
- so will compete for binding site, and will have no effect.
what are examples of drugs that require therapeutic monitoring
Vancomycin
gentamicin
teicoplanin
- to make sure levels of drug is maintained within the therapeutic window.
antimicrobial prescribing considerations
1) is an antimicrobial indicated
2) what is the most appropriate antimicrobial or combo for the INFECTION
3) which drugs can penetrate to the site of infection
4) what is the most appropriate antimicrobial or combo for the SPECIFIC PATIENT
5) what is the most appropriate route
6) what is the most appropriate dose and freq
7) What is the most appropriate course length
minimum inhibitory concentration (MICs)
lowest conc of an antimicrobial that is needed to inhibit visible growth of a microorganism
Minimum bactericidal concentration (MBCs)
lowest conc of antimicrobial needed to prevent growth of an organism
what are the 3 types of antimicrobial classifications (MIC and MBC)
1) concentration dependent/killing
2) time dependent
3) Hybrid
conc dependent
The higher the drug concentration relative to pathogen minimum inhibitory concentration, the greater the rate and extent of antimicrobial activity.
for conc dependent killing, best response is when the drug conc used is more than x10 higher than MIC.
time dependent
dependent on duration of pathogen exposure to antibiotic.
e.g. B- lactams and clindamycin bind for long periods of time
- so their pharmacodynamics can be modified to bind for less amount of time, where drug conc still remains above the MIC
hybrid
mix of conc dependent and time dependent
- and has persistent post antibiotic effect
so works even after the antibiotic has been completely cleared out.
why are tetracyclines not recommended for kids
could cause discolouration and deformity of growing bones and teeth
can ciprofloaxacin be used in kids
no
causes arthropathy (joint disease)
examples of drugs that are avoided or dose reduced with impaired renal or hepatic function
RENAL
Aminoglycosides
vancomycin
HEPATIC
isoniazid
rifampicin
clindamycin
what is the general course length of antimicrobials ?
5 days
When is antimicrobial prophylaxis considered
1) surgery
2) post-splenectomy/dysfunctional spleen
3) Bacterial meningitis
4) TB
5) Immunocompromised
6) HIV
7) Bite wounds
8) malaria
what causes 50% of sepsis cases
pneumonia
what are the 6 parameters for the NEWS scoring system
respiration rate
oxygen saturation
systolic blood pressure
pulse rate
level of consciousness or confusion
temperature
Ciprofloxacin
Drug Class: Fluoroquinolone antibiotic
Indication: Used for a wide range of bacterial infections, including urinary tract infections, respiratory infections, and skin infections.
Mechanism of Action: Inhibits bacterial DNA gyrase and topoisomerase IV, enzymes involved in DNA replication, transcription, and repair, leading to bacterial cell death.
Side Effects: Nausea, diarrhea, dizziness, tendonitis/tendon rupture, photosensitivity, QT prolongation, CNS effects (confusion, seizures), and risk of C. difficile infection.
Doxycycline
Drug Class: Tetracycline antibiotic
Indication: Treatment of various bacterial infections such as respiratory tract infections, Lyme disease, acne, and sexually transmitted infections.
Mechanism of Action: Inhibits bacterial protein synthesis by binding to the 30S ribosomal subunit, preventing tRNA from attaching to the ribosome.
Side Effects: Nausea, vomiting, photosensitivity, gastrointestinal discomfort, esophageal irritation, and tooth discoloration in children.
Amoxicillin
Drug Class: Beta-lactam antibiotic (Penicillin class)
Indication: Used to treat a variety of bacterial infections, including ear infections, sinusitis, bronchitis, and urinary tract infections.
Mechanism of Action: Inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins, leading to cell lysis.
Side Effects: Diarrhea, rash, allergic reactions (hives, anaphylaxis), and gastrointestinal upset.
Azithromycin
Drug Class: Macrolide antibiotic
Indication: Treatment of respiratory infections, sexually transmitted infections, and skin infections.
Mechanism of Action: Binds to the 50S ribosomal subunit, inhibiting bacterial protein synthesis.
Side Effects: Diarrhea, nausea, abdominal pain, QT prolongation, and risk of C. difficile infection.
Piperacillin/Tazobactam
Drug Class: Beta-lactam antibiotic (Piperacillin is a penicillin derivative, and Tazobactam is a beta-lactamase inhibitor)
Indication: Treatment of serious infections, including intra-abdominal, skin, soft tissue, and urinary tract infections.
Mechanism of Action: Piperacillin inhibits bacterial cell wall synthesis, while Tazobactam inhibits beta-lactamases, protecting piperacillin from degradation.
Side Effects: Diarrhea, rash, liver enzyme elevations, allergic reactions, and risk of superinfection.
Flucloxacillin
Drug Class: Beta-lactam antibiotic (Penicillin class)
Indication: Primarily used for infections caused by penicillin-resistant staphylococci, such as skin infections and endocarditis.
Mechanism of Action: Inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins, leading to cell lysis.
Side Effects: Rash, diarrhea, nausea, allergic reactions, and liver toxicity (rare).
Metronidazole
Drug Class: Nitroimidazole antibiotic/antiprotozoal
Indication: Treatment of infections caused by anaerobes, such as bacterial vaginosis, Clostridium difficile infections, and infections from Giardia and Entamoeba histolytica.
Mechanism of Action: Enters bacterial and protozoal cells, where it is reduced to toxic metabolites that bind to DNA and inhibit nucleic acid synthesis, leading to cell death.
Side Effects: Nausea, metallic taste, neurotoxicity (seizures, peripheral neuropathy), and disulfiram-like reaction with alcohol.
Penicillin
Drug Class: Beta-lactam antibiotic (Penicillin class)
Indication: Treats a variety of bacterial infections, including strep throat, syphilis, and pneumonia.
Mechanism of Action: Inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins, leading to bacterial cell lysis.
Side Effects: Allergic reactions (rash, anaphylaxis), gastrointestinal upset, and superinfections.
Gentamicin
Drug Class: Aminoglycoside antibiotic
Indication: Treatment of severe infections caused by Gram-negative bacteria, including sepsis, pneumonia, and urinary tract infections.
Mechanism of Action: Inhibits bacterial protein synthesis by binding to the 30S ribosomal subunit, leading to misreading of mRNA and impaired protein production.
Side Effects: Nephrotoxicity, ototoxicity, neurotoxicity, and risk of superinfection.
Erythromycin
Drug Class: Macrolide antibiotic
Indication: Treatment of respiratory infections, acne, and sexually transmitted infections.
Mechanism of Action: Inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit.
Side Effects: Gastrointestinal upset, nausea, diarrhea, QT prolongation, and potential drug interactions due to CYP450 inhibition.
Clindamycin
Drug Class: Lincosamide antibiotic
Indication: Treatment of infections caused by anaerobic bacteria, including skin and soft tissue infections, and certain bone infections.
Mechanism of Action: Inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit.
Side Effects: Diarrhea, nausea, potential for Clostridium difficile-associated colitis, and skin rashes.
Vancomycin
Drug Class: Glycopeptide antibiotic
Indication: Used to treat serious infections caused by Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA).
Mechanism of Action: Inhibits bacterial cell wall synthesis by binding to the D-alanyl-D-alanine portion of peptidoglycan precursors.
Side Effects: Red man syndrome (flushing, hypotension), nephrotoxicity, ototoxicity, and phlebitis.
Teicoplanin
Drug Class: Glycopeptide antibiotic
Indication: Similar to vancomycin, used for severe Gram-positive bacterial infections, including MRSA.
Mechanism of Action: Inhibits bacterial cell wall synthesis by binding to peptidoglycan precursors.
Side Effects: Rash, fever, phlebitis, nephrotoxicity (rare), and ototoxicity (rare).
Isoniazid
Drug Class: Antitubercular agent
Indication: Primary treatment for active tuberculosis (TB) and prophylaxis for TB exposure.
Mechanism of Action: Inhibits the synthesis of mycolic acids, which are essential components of the bacterial cell wall of Mycobacterium tuberculosis.
Side Effects: Hepatotoxicity, peripheral neuropathy, rash, and elevation in liver enzymes.
Rifamipicin
Drug Class: Rifamycin antibiotic
Indication: Primarily used for the treatment of tuberculosis and other mycobacterial infections, as well as for prophylaxis in cases of meningococcal exposure.
Mechanism of Action: Inhibits bacterial RNA polymerase, preventing transcription and bacterial RNA synthesis.
Side Effects: Hepatotoxicity, orange-red discoloration of bodily fluids (urine, tears, sweat), and potential drug interactions due to liver enzyme induction.
