CellWallInhibitorsC Flashcards
What is the consequence of cell wall inhibitors ?
Cell death
Cell wall inhibitors require what type of organism for maximum effect?
Actively proliferating microorganisms
What are the beta-lactam compounds?
Penicillin, cephs, carbapenems, monobactams and beta-lactamase inhibitors
What main characterist defines beta- lactam drugs?
Beta lactam ring
What are the beta lactams inherently unstable to ?
pH- destroyed in acid
Are beta lactams generally bacteriostatic or cidal?
Cidal- active against growing organisms
What is penicillin MOA?
Interferes with the last step in bacterial cell wall synthesis
Why does penicillin have no effect on protozoa, mycoplasma, viruses and fungus?
b/c they lack cell walls
What are the 3 ways bacteria are resistant to penicillin?
Produce beta lactamase (inactivates drug), modify PBP target, and impair penetration of drug to target PBP
What are the natural penicillins?
G or V
What are the natural penicillins highly active against? What are they not active against?
Active: Gram + cocci, Not active: staphylococcus
What are the indications for natural penicillin use? How are they administered?
Ts: URI/ LRI, throat, skin, and GU infections, G- IM, V- oral
What are the aminopenicillins and how do they differ from the naturals?
Ampicillin and amoxicillin, Have Pen G activity AND improved coverage of gram ñ cocci and enterobacteriaceae
What are the therapeutic uses of aminopenicillins?
URI ( otitis and sinusitis) uncomplicated UTI, meningitis, and salmonella
What is augmentin composed of?
Amoxicillin and calvulonic acid
What are the penicillinose-resistant penicillins?
Nafcillin, oxacillin, dicloxacillin
Do the penicillinose-resistant penicillins have a narrow or broad spectrum use?
Narrow
What are the indications for penicillinose-resistant penicillins ?
Tx staph infections with increased beta lactam production. Cellulitis and endocarditis
What are the penicillinose-resistant penicillins not active against?
Gram ñ or anaerobic organisms
What are the antipseudomonal penicillins? How do they differ from natural penicillins?
Piperacillin, ticarcillin, and carbenicillin. Pen G activity AND gram ñ coverage including pseudomonas
What are the beta-lactamse inhibitors and what do they act as?
Clavulanic acid, sulbactam, and tazobactam ì suicide inhibitorsî ñ potent, irreversible inhibitors of many lactamases
Adding B lactamase inhibitors increases coverage of what organisms?
H influenzae, staph, and moraxella catarrhalis
Which penicillins are oral admin ONLY?
Pen V and amoxicillin with or without clavulanic acid
Which penicillins are IV ONLY?
Antipseudomonal penicillins. Piperacillin with or without tazobactam
Which penicillins are oral or IV?
Nafcillin , Ampicillin
What are the depot forms of penicillin admin?
Procaine and benzathin penicillin G
How are most penicillins eliminated?
Kidney, actively secreted into urine
Which penicillins are excreted via biliary excretion?
Antipseudomonal and nafcillin
What can block active secretion of penicillin?
Probenecid
What are some ADRs of penicillin?
GI upset, diarrhea, and secondary infections
What are drug specific penicillin reactions?
Oxacillin- hepatitis, Nafcillin- neutropenia, Ticarcillin/carbencillin- abnormal platelet aggregation
What are the 2 PCN drug interactions?
TCN- tetracycline or other bacteriostatic agents, Anti-pseudomonal PCN affects warfarin metabolism
Are cephalosporins bactericidal or static?
bacteriocidal
How is there increases cephalosporin resistance?
Mutations carried on plasmids
Cephalosporin generation 1 covers what type of organisms?
Aerobic gram +, Above the diaphragm, anaerobes/CA gram ñ Skin infections, acute otitis media, pharyngitis, UTI, prophylaxis for clean surgery, septic arthritis
What are the 1st generation drugs and the routes?
Cefazolin ( IV), Cephalexin (PO)
What are the 2 categories of 2nd generation cephs and their routes and indications
1-Added gram negative coverage, IV/PO- cefuroxime, cefaclor, cefprozil, Sinusitis, otitis, bronchitis, CAP, skin infections, UTI 2-added anaerobic coverage IV: cefotetan, cefoxitin Abdominal and gyno infections
What was the main added feature for 3rd generation ?
Gram negative coverage and penetration of the BBB
What are the 3rd generation cephs and their routes?
Oral: cefpodoxime, cefdinir, cefixine, cefditoren, cefibuten IV/ IM: cefotaxime, ceftriaxone(long Ω life) IV: ceftazidime- increased antipseudomonal coverage
What are indications for use of 3rd generation cephs?
Wide variety of serious infections that may be resistant to other antimicrobial agents Broad spectrum Meningitis, pneumonia, sepsis, peritonitis, neisseria gonorrhea
What is the 4th generation ceph? Can it be taken orally?
Cefepime, NO - IM/IV
What does generation 4 have good coverage against? What is it used for?
Gram +, -, anaerobic ( h influenzae, n. meningitides, n. gonorrheae, p. aeruginosa )Intraabdominal infections, resp tract infections, skin infection
Is vancomycin a bactericidal or static?
bactericidal
What are the 2 mechanisms of vancomycin resistance?
Acquired or innate
Does vancomycin work against gram ñ organisms?
NO, only gram +
What is vancomycin reserved for?
Pt allergic to beta latams with serious gram + infections or MRSA
When is oral vancomycin indicated?
c.diff induced colitis ONLY
What are the ADR of vancomycin?
Red man syndrome, ototoxicity, nephrotoxicity
What is ovitavanan used for?
Gram + , including MRSA
What is daptomycin used for/ reserved for?
Omplicated skin infections, bacteremia, osteomyelitis, Reserved for: pt allergic to beta lactams, MRSA, enterococcus spp
What is dalbavacin and what is it used for?
Lipoglycopeptide which prevents cross linking and stabilization of cell wall interfering w/ cell wall synthesis. Bactericidal against staph aureus and strep pyogens
What are indications for dalbavacin ?
Skin infection and IVPB
What are clinical uses of bacitracin?
Nephrotoxic, gram + cocci and bacilli so limited to topical use. Locally for wounds, antibiotic ointment, or cleaning wounds in surgery
