Cephalosporins, Carbapenems Dr. Roane Flashcards
What are ESBLs?
-Extended-spectrum beta-lactamases
-mutant
-plasma-mediated
-Hydrolize cephalosporins, penicillins, aztreonam (Monobactam)
-Treat with Carbapenems or cephamycin, sometimes ß-lactam + ß-lactam inhibitor
What is ampC?
ß-lactamase on plasmid
-in many gram (-)
-resistant to many ß-lactams and is not inhibited by clavulanic acid (Augmentin won’t work)
What are enzymes that provide resistance to Carbapenem?
KPC = Klebsiella pneumonia carbapenemase
NDM1 = New Dehli metallo-beta-lactamase 1
How to treat HAI (hospital-acquired) infections?
Augmentin -> Amoxicillin and Clavulanic Acid
Unasyn -> Sulbactam and Ampicillin
Zosyn -> Tazobactam and Piperacillin
Example of Non beta-lactamase inhibitors
Avibactam used with ceftazidime = Avycaz
Relebactam used with imipenem and cilastatin = Recarbrio -> effective against KPC, AmpCs, and ESBLs
The new drug used to treat Acinetobacter infections
Xacduro = Sulbactam and the new beta-lactamase inhibitor DUROLACTAM
Activity of Cephalosporin by activity
1st gen: activity against gra (+) and some (-)
2nd gen: Against some gram (+) and more (-)
3rd gen: no gram (+) more gram (-)
4th gen: gram (-) activity of 3rd gen + gram (+) activtiy of 1st gen
5th gen: same as 4th + MRSA
Why might 4th gen cephalosporin be an issue?
-Broad spectrum drugs (gram (-) activity of the 3rd gen and gram (+) of the 1st gen)
-can kill more bacteria than intended and cause superinfections
Examples of Resistance against Cephalosporins?
-Mutation of PBPs -> lower affinity - Methicillin-resistance (mutation of PBP2A)
-reduced penetration due to mutations of Porins
-Cephalosporinases
-Efflux pumps
MEMORIZE CEPHALOSPORINS
1st: cephalexin and cefazolin
2nd: FUROXI PROZIL ACLOR
Cephalomycins: FOXITIN FOTETAN METAZOLE
3rd: cefTRIAXONE a cefoTAXIme for a ceftaziDIME cefPODOXIME and ceFIXime me cefDINIR
4th: Cefepime
5th: Ceftaroline, Ceftolozane-tazobactam
Adverse reactions of Cephalosporins
-Hypersensitivity: rash to anaphylaxis
-If pt has strong rxn against penicillins -> use cephalosporin with caution
What are the potential side effects of CefoTETAN(2nd) and cefMETAZOLE (2nd)?
-N-methylthiotetrazole
-After metabolism, the NMTT ring is released -> inhibits Vitamin K production -> bleeding
-Disulfiram-like effect: interferes with the activity of acetaldehyde dehydrogenase
-Nephrotoxicity and diarrhea
Information to obtain from patients who take Cefotetan and cefmetazole?
Do you take Warfarin?
Do you drink alcohol?
What is the prototype of Carbapenems and why is it given with cilastatin?
Imipenem (Primaxim) -> always used with cilastatin
-Cilastatin inhibits the drug’s rapid degradation by renal tubular dipeptidase -> protection from renal damage
What are Carbapenems used for?
-Broad spectrum of activity including some Gram (-)
-for some nosocomial infections (healthcare-acquired)
-MOA like other ß-lactams BUT not as well tolerated -> N+V and CNS effects
