Antimicrobial agents Flashcards
Gram +ve vs -ve
Gram positive = purple, thick peptigoclycan cell wall, no outer membrane
Gram negative = pink, thin peptidoglycan cell wall, outer membrane with LPS
What is MIC and AUC
Summarise patterns of Abx activity
What do Beta lactams do?
Inhibit cell wall synthesis
Types of Beta lactams
Penicillins
Cephalosporins
Carbapenems
Glycopeptides
Indications for 3 main penicillins
Penicillin - G+
Amoxicillin - broad spectrum
Flucoxacillin - narrow, skin infections
Cross-reactions of penicillins
10% cephalosporins and carbapenems
Cephalosporins coverage
Newer gens have more G- coverage and less G+
Carbapenems indication
ESBLs
Carbapenem resistant bugs
Acenitobacter
Klebsiella
Glycopeptide indication
G+ only
oral - C diff
IV - MRSA
Glycopeptide side effect
Nephrotoxic
Abx that inhibit protein synthesis and which part of the ribosome do they each work on
TA(50S)
MC(30S)
O(23S component of 50S)
Tetracycline Indication and contraindication
Indication - G+, intracellular
CI - pregnancy, children(Tetra=teratogenic)
Aminoglycoside examples and indication
TAG - tobramycin, amikacin, gentamicin
Indication - G- sepsis (Ami-NO-glycosides)
Aminoglycoside SEs
Ototoxic, nephrotoxic
Macrolides examples and indication
ACE - Azithromycin, Clarithromycin, Erythromycin
Indication - G+ atypical pneumonia
Good for penicillin allergy
Chloramphenicol indication
Eye drops for bacterial conjunctivitis
Chloramphenicol SEs
Aplastic anaemia
Grey baby risk
Oxazolidinone example and indication
Linezolid
G+s, MRSA, VRE
Which Abx inhibit DNA synthesis?
Fluoroquinolones - -floxacins
Nitroimidazoles - -dazoles
Fluoroquinolones example and indication
Ciprofloxacin
Broad spec G-ves
Anti-pseudomonas (fluoroquinolones anti-pseudomonas, q and p are oppposites)
Nitroimidazole example and indication
Metronidazole
Anaerobes and protozoa
RNA synthesis inhibitor
Rifamycins - e.g. Rifampicin
Cell membrane toxins, examples and indication
Polymyxins - Colistin - G-ves
Cyclic lipopeptides - Daptomycin - same as linezolid
Drugs that inhibit folate metabolism with examples
Sulfonamides - sulphamethoxazole (co-trimox for PCP)
Diaminopyrimidines - trimethoprim (UTI)
Broad spectrum Abx
Cures All Types of Microbes
Ciprofloxacin
Co-Amoxiclav
Tazocin
Meropenem
Narrow spectrum Abx
Greatly Fine Margins
Gentamicin
Flucloxacillin
Metronidazole
Anti-pseudomonas Abx
Chefs Take Care Grilling Meat
Ceftazadime
Tazocin
Ciprofloxacin
Gentamicin
Meropenem
4 Mechanisms of Antibiotic resistance
BEAT
Likely organism and Abx choice for skin infection
S. aureus
Fluclox
Likely organism and Abx choice for Pharyngitis
Beta haemolytic strep
Phenoxymethylpenicillin
Abx choice for nosocomial UTI
Co-amoxiclav or Cephalexin
Abx choice for severe sepsis
Tazocin / ceftriaxone
Metronidazole
+- Gentamicin
Abx choice for neutropenic sepsis
Tazocin + Gentamicin
Likely organism and Abx for colitis
C diff
Oral vancomycin
