Drugs that inhibit Cell wall synthesis

Question 1

Penecillin

Answer 1

-V (oral), G (IV), Benzathine (IM)
-Binds penecillin binding protein, inhibits transpepetidase
-Spectrum: Gram+, some Gram-, narrow
-Allergies: 5-10%
Side effects: Hypersensitivity- mild rash to anaphylaxis, seizure, nausea, diarrhea
Resistance: Penicillinase

Question 2

Nafcillin, dicloxacillin, antistaph penicillins

Answer 2

Penicillanse-resistance penicillins

• Mech: Binds to PBP, larger R group so resistant to p-ases
• Spec: very narrow, MSSA
• Allergy: Hapten proton complex
• Side effects: Hypersensitivity
• Resistant: broad spectrum Beta-lactams (resistant to penicillinases)

Question 3

Clavulanate (penicillin), Sulbactam, Tazabactam

Answer 3

Beta-lactamase inhibitors

• Mech: binds irreversibly to beta-lactamase
• Spec: Beta-lactamase enzymes
• Co-drugs: Penicillin, Beta-lactam drugs

Question 4

Ampicillin, Amoxicillin

Answer 4

Aminopenicillins
-Mech: Water soluble, can pass through porins, binds PBP
-Spec: Gram+, Gram-, wider spectrum
-Co drugs: Ampicillin/sulbactam, Amoxicillin/clavulanate
-Allergies: Hapten prtn complex
-Side effects: Hypersensitivity, ampicillin= pseudomo-membranous colitis
Resistance: Beta-lactamases susceptible

Question 5

Ticarcillin, pipercillin

Answer 5

Anti-pseudomoal penicillin
Mech: binds PBP
Spec: Gram+, Gram-, usually only pseudomonas
Co-drugs: Ticarcillin/clavulanate, Piperacillin/tazobactam
Allergy: Hapten prtn complex
Resistance: Penicillinase susceptible

Question 6

Aztreonam

Answer 6

Monobactam
mech: Monocyclic beta-lactam, binds PBP
Spec: Gram-, Klebsiella, Pseudomonas, Serratia
Co-drug: Beta-lactamase inhibitor
Resistance: extended spectrum beta-lactamases

Question 7

Cephalosporins (general)

Answer 7

Excreted by kidney (watch for renal insufficiency)
Mech: Binds PBP
Co-drug: beta-lactamase inhibitor
Allergy: Hapten prtn complex
Side effects: Hypersensitivity
Resistance: Extended spectrum beta-lactamases

Question 8

Cephalexin (1st gen ceph)

Answer 8

Use: surgical prophylaxis
Spec: Gram+
Note: Can’t cross BBB

Question 9

Cefoxitin (2nd gen ceph)

Answer 9

Use: immediately prior to surgery
Spec: more Gram-, weaker against Gram+
Note: Can’t cross BBB, can inhibit Vit K production/increased bleeding
–Disulfiram-like rxn with EtOH

Question 10

Ceftriaxone, Cefotraxime, Cetazidime, Cefdinir (3rd gen ceph)

Answer 10

Spec: Strep, serious gram-, meningitis
Note: Can cross BBB for meningitis treatment
Interacts with Ca2+ to form crystals, precipitate in lungs and kidneys

Question 11

Cefepime (4th gen ceph)

Answer 11

Spec: Broadest spectrum Gram+/-, pseudomonas

Question 12

Ceftaroline (5th gen ceph)

Answer 12

Mech: Binds to PVP 2a present ini MRSA
Spec: MRSA, CABP, ABSSSI

Question 13

Imipene, meropenem

Answer 13

Carbapenems
Mech: Binds PBP
Spec: Broad, not MRSA
Co-drug: Imipine/cilastatin (decreases cleavage of beta-lactam ring)
Allergies: Cross allergic w/ penicillins
Side effects: GI distress, seizures if renal dysfunction
Resistance: Change in PBP, low susceptibility to beta-lactamases

Question 14

Vancomycin

Answer 14

Note: oral vanco is poorly aborbed
Mech: Prevents elongation of PPG cell wall
Side effects: Nephrotoxic when given IM
Resistance: rare

Question 15

Bacitracin

Answer 15

Note: Poor bioavailability, topical ophthalmic and derm preps
Mech: Bind to LPS and create holes in outer membrane
Spec: Gram-, Pseudomonas, Klebsiella
Co-drugs: Helps to facilitate entry of all drugs
Resistance: Infrequent, slow

Question 16

Daptomycin

Answer 16

Mech: binds to cell membrane and aggregates, depolarizing cell wall
Spec: Gram+, vanco-resistant MRSA
Side effects: Reversible organizing pneumonia binds pulmonary surfactant
Resistance: Addition of lysine to cell surface (repels (+)charged drug)

Question 17

Polymixin B

Answer 17

Mech: Binds to LPS and creates pores to facilitate entry into cell
Spec: Gram-, pseudomonas, klebsiella
Resistance: infrequent, slow
Note: used to facilitate entry of other drugs