Antimicrobial agents Flashcards
Beta Lactams
- Target?
- classes?
- examples?
- used to treat?
- Inhibit cell wall synthesis
- Penicillins, cephalosporins, carbapenems
- Benzylpenicillin, ceftriaxone, meropenem
- Treats Gram +ves, and 3rd generation ceph’s and carb’s treat some Gram -ve
Glycopeptides
- Target?
- examples?
- used to treat?
- Inhibit cell wall synthesis
- Vancomycin, Teicoplanin
- MRSA, C.Diff
Aminoglycosides
- Target?
- examples?
- used to treat?
- Inhibit protein synthesis
- Gentamicin
- Gram negative sepsis
Tetracyclines
- Target?
- examples?
- used to treat?
- Inhibit protein synthesis
- Doxycycline
- Intracellular - chlamydia
Macrolides
- Target?
- examples?
- used to treat?
- Inhibit Protein synthesis
- Erythromycin
- Gram +ve (PCN allergy)
Chloramphenicol
- Target?
- examples?
- used to treat?
- Inhibit protein synthesis
- Eye drops
- Bacterial conjunctivitis
Oxazolidinones
- Target?
- examples?
- used to treat?
- Inhibit protein synthesis
- Linezolid
- Gram +ve, MRSA +VRE
Fluoroquinolones
- Target?
- examples?
- used to treat?
- Inhibit DNA synthesis
- Ciprofloxacin
- Gram -ve
Nitroimidazoles
- Target?
- examples?
- used to treat?
- Inhibit DNA synthesis
- Metronidazole
- Anaerobes and Protozoa
Rifamycin
- Target?
- examples?
- used to treat?
- Inhibit RNA synthesis
- Rifampicin
- Mycobacteria- used in TB
Polymyxin
- Target?
- examples?
- used to treat?
- Cell membrane toxin
- Colistin
- Gram -ve
Cyclic lipopeptide
- Target?
- examples?
- used to treat?
- Cell membrane toxin
- Daptomycin
- Gram +ve, MRSA + VRE
Sulfonamides
- Target?
- examples?
- used to treat?
- Inhibit folate metabolism
- Sulphamethoxazole
- PCP
Diaminopyrimidines
- Target?
- examples?
- used to treat?
- Inhibit folate metabolism
- Trimethoprim
- UTI
Name 2 of the most common Gram +ve organisms
Staphylococcus Streptococcus
Name 2 of the most common Gram -ve organisms
E. coli Psuedomonas
Define a broad-spectrum antibiotic
An antibiotic that acts against a wide range of disease-causing bacteria, including both Gram-positive and Gram-negative bacteria. A narrow-spectrum antibiotic is only effective against specific families of bacteria.
List 4 commonly prescribed broad-spectrum antibiotics
Co-amoxiclav Tazocin Ciprofloxacin Meropenem
List 3 commonly prescribed narrow-spectrum antibiotics
Flucloxacillin Metronidazole Gentamicin
The mnemonic BEAT is used to remember the 4 mechanisms of antibiotic resistance. List the 4 mechanisms and give an example of each
- Bypass antibiotic-sensitive step in pathways (eg MRSA) - Enzyme-mediated drug inactivation (eg beta-lactamases) - Accumulation impairment (eg tetracycline resistance) - Target modification (eg quinolone resistance)
What is the most common causative organism for skin infections?
Staph aureus
Which antibiotic is typically used for the empirical treatment of skin infections?
Flucloxacillin (unless allergic or MRSA +ve)
What is the most common causative organism for pharyngitis?
Beta-haemolytic strep
Which antibiotic is typically used for the empirical treatment of pharyngitis?
Benzylpenicllin
Which antibiotic is typically used for the empirical treatment of mild community-acquired pneumonia?
Amoxicillin
Which 2 antibiotics are typically used for the empirical treatment of severe community-acquired pneumonia?
Cefuroxime and Clarithromycin
Which antibiotic is typically used for the empirical treatment of hospital-acquired pneumonia?
Cefuroxime
What are the 2 most common causative organisms for bacterial meningitis?
Meningococcus / streptococcus
Which antibiotic is typically used for the empirical treatment of bacterial meningitis?
Ceftriaxone OR Amoxicillin if listeria suspected - ie if pt is very young, old or immunocompromised
Which antibiotic is typically used for the empirical treatment of community acquired UTI?
Trimethoprim (for 3 days)
Which antibiotic is typically used for the empirical treatment of hospital-acquired (nosocomial) UTI?
Co-amoxiclav OR Cephalexin
Which antibiotics are typically used for the empirical treatment of severe sepsis?
Cefuroxime, Metronidazole +/- Gentamicin
Which antibiotics are typically used for the empirical treatment of neutropaenic sepsis?
Tazocin + Gentamicin
What is the most common causative organism for bacterial colitis?
Clostridium difficile
Which antibiotic is typically used for the empirical treatment of bacterial colitis?
Metronidazole PO (+ any cephalosporins must be STOPPED)
