Drugs that weaken cell walls: monobactam, carbapenems, cephalosporins, glycopeptides, fosfomycin Flashcards
What is Monobactam - Aztreonam (Azactam) active against?
- Gram - organisms
- Covers PSEUDOMONAS
- Used in infections with multiple drug resistance - reserved agents
MOA Of Monobactam - Aztreonam (Azactam) (3)
1) Binds to PBP
2) inhibits cell wall synthesis
3) promotes cell lysis and death
ADR, Cross reactivity and metabolism/ excretion of Monobactam - Aztreonam (Azactam)
- little to no allergy cross reactivity with penicillins or cephalosporins
- ADR:
- neutropenia- particularly in children*
- increased liver enzymes (ALT, AST)
- metabolism/ excretion: renal adjustments needed but no hepatic adjustment needed
Monobactam drug
Aztreonam (AZACTAM)
Carbapenem drugs
1) Doripenem
2) imipenem/cilastatin
3) meropenem (merrem)
4) Ertapenem (invanz)
DIME DRUGS
Use for carbapenems
- extremely broad spectrum antibiotics- restricted by most institutions
- reserved for infectious disease consult or positive culture/ susceptibilities
- MSSA, GP, GN, Pseudomonas, Anaerobes
- ertapenem doesn’t do pseudomonas
Doripenem, imipenem, and Meropnem use and dosage
Cover MSSA to PSEUDOMONAS
- dosed 2-3 times a day
- COVERAGE OF ANAEROBES
Ertapenem use
no PSEUDOMONAS COVERAGE, but dosed ONCE daily
- used outpatient infusion drug for MDR gram negative
- COVERAGE OF ANAEROBES
CRE
carbapenem resistant enterobacteriaceae
- most resistant bacteria out there
cross reactivity of carbapenems
little to no cross reactivity with cephalosporins or penicillins. get a decent amount of use because of drug allergies
metabolism/ excretion of carbapenems
renal adjustments needed but no hepatic adjustment needed
Cephalosporins uses
- MOST WIDELY USED GROUP OF ANTIBIOTICS
- beta lactam antibiotics, structure similar to penicillin
Cephalosporin MOA
1) Bind to PBP
2) disrupt cell wall synthesis causing cell lysis
Cross reactivity of cephalosporins
Cross reactivity of cephalosporins to penicillin is low. More likely that they are allergic to two different antibiotic classes that truly cross react. most likely cross reactive at the first generation
First generation of Cephalosporin (2)
1) Cephalexin (keflex)
2) cefazolin (ancef)
- used for surgical prophylaxis, skin soft tissue infections
- major use of keflex against UTI
(MSSA, Gram + and some Gram -)
Second generation of Cephalosporin (1)
Cefuroxime
- oral agent used in many types of infections - a lot of respiratory bacterial infections when cultures never resulted
- (MSSA, Gram +, Gram -)
3rd generation of cephalosporin (3)
1) Ceftriaxone (Rocephin)
2) Ceftazidime
3) Cefdinir
(one, dime, (to) dinner)
- rocephin is VERY COMMON used against community acquired pneumonia, UTI, and Gram - bacteremia, meningitis
- ceftazidime- pseudomonal coverage
- cefdinir- oral similar to cefuroxine in use
- (all= gram - and some gram +)
4th generation cephalosporin (1)
- think PSEUDOMONAL COVERAGE
1) cefepime (maxipime) - similar uses to piperacillin/tazobactam (zosyn), except NO ANAEROBIC COVERAGE.
(MSSA, Gram +, Gram -, Pseudomonas) - does not have same risk of nephrotoxicity so use in combo with Vanco
-(pime is close to p in piperacillin and they have similar action)
5th generation cephalosporin (1)
1) Ceftaroline (rarely used)- MRSA COVERAGE
2) ONLY Cephalosporin that has MRSA coverage
(MRSA, MSSA, Gram +, Gram -, Pseudomonas)
like 4th generation (ceftapime + mrsa), no anaerobe coverage
What are glycopeptides
- group of antibiotics with Gram + activity, used primarily in:
1) MRSA
2) patient with PCN allergies
3) C. diff infections - no GRAM - coverage*
- vancomycin is the primary agent in this class
- (MRSA, MSSA, Gram +)
MOA of glycopeptides
1) inhibit cell wall synthesis –> promoting bacterial lysis and death
Route of administration for glycopeptides
- poor oral absorption
- all are IV except vancomycine for C. diff treatment
Vancomycin uses
- used frequently in cellulitis cases as it covers staph and strep until cultures are resulted and G + bacteremia
- also used for fair amount in pneumonia
-MRSA, MSSA, Gram +
ADRs for vancomycin (3)
1) nephrotoxic - renal failure
- need to have blood level monitoring and adjustment
2) RED MAN SYNDROME- rapid infusion can cause histamine release (flushing, rash, pruritis, tachycardia, hypotension)
3) Thrombocytopenia - decreased platelets
Routes for Vancomycin
-IV for all indications EXCEPT c/difficile (oral)
Fosfomycin (monurol) indications
Uncomplicated UTI.
ONLY effective in the bladder- not for pyelonephritis or other systemic infection
- also by IV for “compassion use”
- covers pseudomonas, GNR, enterococcus (even VRE), Gram +
MOA of Fosfomycin (monurol)
inhibits bacterial cell wall synthesis
Routes for fosfomycin (monurol)
oral packet - dissolve in water- dosed with one dose with option of repeat dose in 48-72 hours
ADR of fosfomycin (monurol)
Well tolerated. no adr
