Bacterial Infections of the Lung - Mechs. of Resitance Flashcards
Macrolides
MOR?
(MYCINS)
• Ribosomal Methylation and Mutation of 23S rRNA
• Active Efflux
Tetracyclines
MOR?
(CYCLINEs)
• Decreased entry
• Increased Efflux
• Target Insensitivity
Fluroquinolones
MOR?
(FLOXACINs)
• Mutation of DNA gyrase
• Active Efflux
Penicillins
MOR?
(CILLINs)
• Drug inactivation (ß-lactamase)
• Altered PBPs (target insensitivity)
Cephalosporins
MOR?
(CEFs or CEPHs)
• Decreased permeability or gram - outer membrane (altered porins)
• Active Efflux
Aminoglycosides
MOR?
- Drug Inactivation (aminoglycoside modifying enzyme)
- Decreased permeability of gram - outer membrane
- Active efflux
- Ribosomal methylation
Vancomycin
MOR?
Replacement of D-ala by D-lactate
A patient is treated with an antibiotic that elicited a hypersensitivity reaction. It is noted on the patients chart that they are allergic to penicillin. What would be the best alternate drug options for this patient, assuming you want a drug with the same MOA?
ß-lactamase alternates less likely to trigger hypersensivity:
• Cephalosporins (cefazolin, cefepime, ceftazidime, ceftriaxone)
• Meropenem
• Piperacillin
DO NOT USE drugs like Amoxicillin or Ampicillin
What cephalosporin can you give to someone who is typically allergic to cephalosporins?
NONE - there is COMPLETE cross-reactivity across cephalosporins
A patient is started on an antibiotic and begins to develop a yellow hue to their sclera. Name 2 drugs that this could be.
Macrolides
• Azithromycin
• Erythromycin
What antibiotic may stunt bone growth?
• what other effects might you see?
• Doxycycline - chelates Ca2+
Other Side effects:
• Teeth Discoloration
• Photosensitivity
What antibiotic is known to cause neuromusclar paralysis?
• what other effects might you see?
• Gentamicin
Other Side Effects:
• Nephrotoxicity
• Ototoxicity
What is the most notable adverse effect of Levofloxacin?
Levofloxacin (fluroquinolone)
- Tendon Rupture
- Cartilage Damage in childer
Soon after getting put on an antibiotic for septic shock a man begins to develop siezures. Name two drugs that could do this?
Carbapenems:
• Imipenem (most likely - for adverse effects)
• Meropenem
Other than gentamicin name another antibiotic that causes Nephro- and ototoxicity.
• what other side effects does this drug have?
Vancomycin
Other Side Effects:
• Red Man Syndrome
What antibiotic should not be given with any type of ß2-agonist?
• why?
• Name another adverse effect of this drug.
• Linezolid - its a non-specific MAOI (monoamine oxidase inhibitor)
Other Side Effects:
• BONE MARROW SUPPRESSION - could see a pancytopenia
What antibiotic should never be given to someone with a pre-existing coagulopathy?
• Piperacillin
What drugs may prolong the QT interval?
• which of these also is a major CYP3A4 inhibitor?
Macrolides:
• Azithromycin
• Erthromycin - also inhibits CYP and Pgp
(notice clarithromycin is not included)
Which antibiotics should generally be avoided when breastfeeding?
- Clarithromycin (note: other macrolides are safe)
- Linezolid
- Metronidazole
- Piperacillin
Candidiasis and rash develops in a breastfeeding infant whose mother had a recent bout of pneumonia. What drug was the most likely cause?
Piperacillin
What drug may cause hepatotoxicity in pregnancy?
Erythromycin
What drug may cause damage to the 8th cranial nerve in a developing fetus?
Gentimycin - may damage the vestibulocochlear nerve
What is the function of Cilastin?
• what antibiotic is it most likey to be administered with?
Cilastin:
• Reversible, competitive inhibitor of renal dehyropeptidiase-1 (DHP-1) and enzyme that breaks down impipenem to NEPHROTOXIC metabolites
A patient develops pneumonia following infection with strep. pneumonae (gram +) and is administered Daptomycin. He dies 3 days later after succumbing to the infection. Why?
Daptomycin is DENATURED by lung surfactant so it is useless in the treatment of pulmonary infection
