Drugs for bacterial infections 2 Flashcards
What should you NOT compare on a C&S report?
the MIC of different classes of antibiotics
What are examples of tetracyclines?
tetracyclline, doxycycline, minocycline
are tetracyclines bacteriostatic or bactericidal?
bacteriostatic
What’s the MOA of tetracyclines?
inhibit protein synthesis w/ binding to 30S ribosomal subunit and blocking binding of aminoacyl transfer-RNA
What are ADRs of tetracyclines?
photosensitivity, GI intolerance, stain on developing teeth (<8yo), cannot take in pregnancy!
What do tetracyclines have a drug interaction with?
DI w/ polyvalent cations decreasing absorption – must take two hours before or after medications
When are tetracyclines reliable to use?
atypicals, plasmodium (malaria), rickettsia, spirochetes
When are tetracyclines moderate to use?
staph (MRSA), s pneumoniae
What can you not gram-stain b/c they lack a peptidoglycan layer?
atypicals
When are tetracyclines clinically utilized?
respiratory tract infections, SSTI, syphilis, PID (w/ cefoxitin), malaria prophylaxis, acne
When are tetracyclines your DOC?
tick-borne diseases, chlamydia
What are examples of macrolides?
erythromycin, clarithromcin, azithromycin
What’s the MOA of macrolides?
bacterioSTATIC
inhibit protein synthesis by binding to 50s ribosomal units, inhibiting translocation of peptidase chain
What do macrolides do that cause major DIs?
inhibit CYP450 clarithro and erythro only major DIs!
What are ADRs of macrolides?
GI effects (erythro is the worst), hepatic effects, Qtc prolongation
When are macrolides relibale?
atypicals, h. flu (NOT erythro), h. pylori (clarithro), mycobacterium avium
When are macrolides moderate?
s. pneumoniae, s. pyogenes
When are macrolides clinically utilized?
resp infections, atypical mycobacterial infections, traveler’s diarrhea (azi), SSTI if PCN allergic
When are macrolides your DOC?
chlamydia (azithromycin) H. pylori (clarithromycin –metallic taste)
What are examples of oxazolidinones?
linezolid and tedizolid
What’s the MOA of oxazolidinones?
bacterioSTATIC
inhibit protein synthesis by binding to 23S RNA of 50s subunit, preventing translation
How are oxazolidinones orally bioavailble?
100%
When should you be cautious with using oxazolidinones?
sympathomimmetics and SSRIs – weak MAO inhibitor and can cause serotonin syndrome
What are ADRs of oxazolidinones?
thrombocytopenia, peripheral and optic neuropathy, lactic acidosis
When are oxazolidinones reliable?
MSSA, MRSA, strep (resistant s. pneumoniae), enterococci (including VRE)
hospital based!
When are oxazolidinones moderate?
some atypicals
When are oxazolidinones clinically utilized?
infections caused by GPC (MRSA, VRE) like SSTIs, and hospital associated pneumonia
What’s clindamycin?
lincosamide
What’s the MOA of lincosamides?
inhibits protein synthesis by reversibly binding to 50S
What’s the oral bioavailability of lincosamides?
90%
What’s the eagle effect?
bacteria exposed to concentrations higher than optimal concentration survive more
What are ADRs of lincosamide?
GI intolerance (C. dif colitis)
When are lincosamides reliable?
many G+ anaerobes, plasmodium species (malaria)