Abx (random) Flashcards
What is the CRP and procalcitonin level for infection?
CRP >40
Procalcitonin >0.5 to start abx
Why is doxycycline CI in pregnancy?
Cross placental barrier, concentrate in metal bones and dentition (teeth)
What antibiotics are not suitable for pregnancy?
Tetracycline, fluoroquinolone, co-trimoxazole, aminoglycosides, nitrofurantoin (near term)
Why is fluoroquinolone CI in pregnancy?
Arthropathy (in animal studies)
Why is co-trimoxazole CI in pregnancy?
1st trimester: neural tube defects (folate antagonism of TMP)
3rd trimester: kernicterus
What are examples of time-dependent antibiotics?
Beta-lactams
What are examples of concentration-dependent antibiotics?
Aminoglycosides, fluoroquinolones, metronidazole
What drugs can be used to treat CNS infections? (can cross BBB)
Ampicillin, 3rd & 4th gen cephalosporin, meropenem, vancomycin
Why cannot use daptomycin for pneumonia?
It is inactivated by lung surfactants
Which classes are bactericidal?
Beta-lactams
Glycopeptides (vancomycin)
Aminoglycosides
Fluoroquinolones
Which classes are bacteriostatic?
Macrolides, clindamycin, tetracyclines, trimethoprim and sulphonamides, nitrofurantoin
What are QTc prolonging abx?
Macrolides, fluoroquinolone, azoles
What are nephrotoxic abx?
Aminoglycosides, vancomycin, amphotericin B
What are abx that cause photosensitivity?
Tetracyclines, fluoroquinolone, sulfonamides, pyrazinamide
What abx targets pseudomonas?
Pip-tazo, ceftazidime, cefepime, levofloxacin, ciprofloxacin, aminoglycosides, meropenem, imipenem, aztreonam (9)
What abx targets atypicals?
Tetracyclines, macrolides, levofloxacin, moxifloxacin (4)
What abx targets C diff?
Vancomycin (PO), metronidazole
What abx targets MRSA?
Vancomycin, tigecycline, linezolid, ceftaroline (4)
(maybe) doxycycline, co-trimoxazole, clindamycin, levofloxacin, moxifloxacin (5)
What abx covers ESBL bacteria?
Carbapenems, aminoglycosides
Which carbapenem is the odd one out in terms of coverage?
Ertapenem: no enterococcus and pseudomonas cover
What to monitor for vancomycin?
strict I/O, infusion reaction, U/E/Cr
Peak and trough levels for vancomycin? Target AUC/MIC? Sampling times for peak and trough?
Peak <40
Trough 10-15 (15-20 for MRSA)
AUC/MIC 400-600
Sampling time: 1h after end of infusion (peak), immediately before starting infusion (trough)
Peak and trough levels for aminoglycosides? Sampling times for peak and trough?
Gentamicin: peak 8-10, trough <2
Amikacin: peak 25-40, trough <10
Sampling time: 1h after end of infusion (peak), 1h before starting infusion (trough)
Which abx cannot be used in G6PD deficient patients?
Nitrofurantoin, FQ, co-trimoxazole
What are atypicals?
Legionella sp, Mycoplasma pneumoniae, Chlamydia pneumoniae
Tigecycline coverage
MRSA, VRE, streptococci, ESBL
(not pseudomonas, proteus)
Which macrolide has the least CYP3A4 enzyme inhibition?
Azithromycin
Which macrolide enhances gastric motility?
Erythromycin
Which abx is used for triple therapy PUD?
Clarithromycin, metronidazole / amoxicillin (and PPI)
Which abx causes ototoxicity?
Macrolides, vancomycin, aminoglycosides
What abx are cleared hepatically?
Ceftriaxone, macrolides, clindamycin, moxifloxacin, metronidazole
What abx are cleared renally?
Beta-lactams, vancomycin, tetracyclines (minocycline metabolised by kidney before excretion -> hepatic impairment dose adjustment), aminoglycosides, ciprofloxacin, levofloxacin, co-trimoxazole, nitrofurantoin
Can linezolid be used for catheter-related bloodstream infections or catheter-site infections?
No
Nitrofurantoin coverage?
E coli, Enterococcus (not pseudomonas or proteus)
What antifungals are renally cleared?
Amphotericin B, 5-FU, fluconazole
What causes bone marrow suppression as a side effect?
Linezolid, amphotericin B, 5-FU
Antifungal CSF penetration?
Amp B (conventional) < Amp B (lipo) < 5-FU
What antifungals are hepatically cleared?
Itraconazole, Voriconazole
What are the common bugs involved in nosocomial infections?
ESKAPE (Enterococcus faecium, Staph Aureus MRSA, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp.)
Which abx are bacteriostatic normally but bactericidal at high doses?
Macrolides, nitrofurantoin
Side effects of 5-FU
hepatotoxicity, GI side effects, bone marrow suppression
Side effects of Amphotericin B
- Fever and chills (1-3h after starting IV)
- Nephrotoxicity (conventional causes renal vasoconstrictions and reduce GFR) -> hydrate pts
- Electrolyte imbalances (hypoK)
- Thrombophlebitis
- Bone marrow suppression, anaemia
Which abx do not have activity against Strep pneumoniae?
Cloxacillin, 1st gen cephalosporins, ceftazidime, aminoglycosides, ciprofloxacin
