Antibiotics Flashcards
Where are MRSA swabs taken from
- nose, throat
- groin
- armpits
- wounds
- entry sites for invasive devices eg stoma, catheter
- umbilicus (infants only)
Bacteria that causes a fruity smell on culture
Pseudomonas aeruginosa
Alcohol can induce vomiting if consumed within 48 hours of taking what antibiotic
Metronidazole
What a/b(s) are used to treat MRSA
- vancomycin
- teicoplanin
(prontoderm to get off skin)
What a/b(s) are used to treat anaerobic bacteria
Metronidazole
add to broad spectrum cephalosporin
Definition of clean surgery
No breach of hollow organ
Definition of clean contaminated surgery
Hollow viscus breached
eg cholecystectomy
Definition of contaminated surgery
eg appendectomy, bowel resection
Definition of dirty surgery
Pus present in operating site
eg perforated colon
What a/b to give asymptomatic contacts of syphilis patient
Doxycycline
14 days
What a/b to give purulent conjunctivitis
Chlormaphenicol eye drops
What a/b to give otitis externa
Topical tx (see BNF)
Flucloxacillin if spreading cellulitis
What a/b to give otitis media
NOTE: usually viral, no need a/b
Ampicillin/Amoxicillin if no improvement after 72h
What a/b to give sinusitis
NOTE: only give if persistent symptoms + purulent discharge for 7 days
Ampicillin/Amoxicillin
7 days
Class and mode of action of the following a/b:
Vancomycin
Glycopeptide
```
Prevents transglycosylation
Inhibits cell wall integrity
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Class and mode of action of the following a/b:
Gentamycin
Aminoglycoside
Binds irreversibly to 30s subunit
Ribosome cannot fit mRNA
Inhibits protein synthesis
Class and mode of action of the following a/b:
Erythromycin
Macrolide
Binds reversibly to 50s subunit
Blocks P site on ribosome
Inhibits protein synthesis
Class and mode of action of the following a/b:
Doxycycline
Tetracycline
Binds reversibly to 30s subunit
Stops binding of tRNA to mRNA
Inhibits protein synthesis
Class and mode of action of the following a/b:
Clindamycin
Similar to macrolides but separate class
Binds reversibly to 50s subunit
Blocks P site on ribosome
Inhibits protein synthesis
Mode of action of the following a/b:
Metronidazole
Nitroimidazole
Inhibits nucleic acid synthesis
Mode of action of the following a/b:
Nitrofurantoin
Damages DNA
Mode of action of the following a/b:
Trimethoprim
Blocks dihydrofolate reductase
Folate inhibitor
cannot be given to pregnant women
Class and Mode of action of the following a/b:
Sulfasalazine
Sulfonamides
Blocks dihydrofolate synthase
Folate inhibitor
(?safe for pregnant women)
Which classes are beta lactams?
- penicillins
- cephalosporins
- carbapenems
- monobactams
How do beta lactams work as a/b?
Disrupt cell wall synthesis
Name example(s) of beta lactamase resistant a/b
- flucoxacillin
- methylcillin
Define bacteriocidal vs bacteriostatic
Bacteriocidal = kills bacteria
Bacteriostatic = stops replication of bacteria
Examples of classes of bacteriocidal a/b
- penicillins
- cephalosporins
- carbapenams
- monobactams
- glycopeptides eg vancomycin
- metronidazole
- nitrofurantoin
Examples of classes of bacteriostatic a/b
INHIBIT FOLATE SYNTHESIS
- trimethoprim
- sulfonamides
INHIBIT PROTEIN SYNTHESIS
- clindamycin
- macrolides
- tetracyclines
- aminoglycosides
Which a/b might cause Steven Johnson syndrome
Trimethoprim
Which a/b might cause Red Man syndrome
Vancomycin
and other glycopeptides
Describe Steven Johnson syndrome
Type 4 hypersensitivity reaction
Fever + flu-like symptoms then skin blisters and peels
Describe Red Man syndrome
Red rash
Severe complications of Steven Johnson syndrome
Multiple organ failure
Severe complications of Steven Johnson syndrome
- Multiple organ failure
- scar tissue inside eyelids leading to impaired vision
How to avoid Red Man syndrome
Infuse vancomycin slowly (over >60min interval)
Which a/b inhibit cell wall synthesis
- penicillins
- cephalosporins
- carbapenems
- monobactams
- glycopeptides eg vancomycin
Which a/b inhibit protein synthesis
- tetracyclines
- aminoglycosides
- macrolides
- clindamycin
Which a/b inhibit folate synthesis
- trimethoprim
- sulphonamides
Which a/b inhibit DNA synthesis
- metronidazole
- quinolones (inhibit DNA gyrase)
- nitrofurantoin (damages DNA)
Main side effects of gentamycin
- ototoxic
2. nephrotoxic
Main side effects of co-trimoxazole (trimethoprim + sulfamethoxazole)
- nausea
- nephrotoxic, hepatotoxic
- Steven Johnson syndrome
- Bone marrow suppression
