MICRO drugs

MOA for natural penicillins

inhibits transpeptidases (build and repair wall)

spectrum of natural penicillin’s

narrow only Gm +

advantages/disadvantages of natural penicillins

safe and inexpensive

quick resistance and only gm +

semi synthetic penicillin’s MOA

inhibits transpeptidases (build and repair wall)

spectrum of semi-synthetic penicillins

medium some gm- gm+

semi-synthetic pencillins drugs

amoxicillans

semi-synthetic penicillin advantages/disadvantages

broaden spectrum but still quick resistance

anti- beta lactamases MOA 1

clavulanic acid inhibits the enzymes for cell wall

anti-beta lacatmases spectrum 1

medium some gm- gm+

anti B lacatamases advantages/disadvantages 1

amoxicillin expanded

anti- beta lacatmases drugs 1

clavamox/ augmentin

anti- beta lactamases MOA 2

inhibits staph B lacatmases

anti beta lactamases spectrum 2

broad both gm -/+

anti beta lactamases advantages/disadvantages 2

treats s. aureus not MRSA

anti beta lactamases drugs 2

oxacillin/methicillin

cephalosporins MOA

inhibits transpeptidases (build + repair cell wall)

cephalosporins spectrum

broad gm-/+

cephalosporins advantages/disadvantages

2 r groups make it difficult to degrade the drug

cephalosporin drugs

ceftriaxone

glycopeptide MOA

prevents NAG/NAMs from linking

glycopeptide spectrum

narrow Gm+

glycopeptide advantages/disadvantages

treats MRSA and staph/strep, but needs to be injected

glycopeptide drugs

vancomycin

polypeptide MOA

prevents transport of NAM/NAG from cytoplasm to cell wall

polypeptide spectrum

narrow only Gm + for strep/staph

polypeptide advantages/disadvantages

great w/topical but has to be injected

polypeptide drugs

bacitracin (also Neosporin)

amino-glycosides MOA

prevents reading of mRNA small subunit (30S)

amino-glycosides spectrum

Broad gm-/+

amino-glycosides advantages/disadvantages

prevents proper reading of mRNA

amino-glycosides drugs

kanamycin, streptomycin, gentamycin

amphenicols MOA

inhibits peptide bond formation

amphenicols spectrum

broad gm-/+

amphenicols drugs

chloramphenicol

tetracycline MOA

prevents tRNA from binding the reading unit

tetracycline spectrum

broad (gm-/+)

tetracycline drugs

tetracycline

polymyxins MOA

disrupts outer membrane by binding to LPS and disrupts phospholipids

polymyxins spectrum

narrow (gm-)

polymyxins advantages/disadvantages

old drugs to treat resistant strains, but can interfere with host cell membranes

polymyxins drugs

colistin

quinolones MOA

block DNA unwinding for replication

quinolones spectrum

broad gm-/+

quinolones advantages/disadvantages

effective when all else fails, but cannot get rid of C. diff and can wipe out good microbes

quinolones drugs

ciprofloxacin

sulfamides MOA

blocks folic acid which is building block for DNA, RNA and AA so no synthesis can occur

sulfamides spectrum

broad (gm+ gm-)

sulfamides disadvantages

allergic reactions

sulfamides drugs

trimethoprim

Fuzeon MOA

prevents fusion of virus and host

Fuzeon spectrum

narrow specfically HIV d

Fuzeon advantages

improves efficacy in combination with other drugs

Tamiflu MOA

prevents fusion of virus and host cell

Tamiflu spectrum

narrow just for influenza

acyclovir MOA

stops replication and mimics nucleotides

acyclovir spectrum

narrow - just for herpes

polyenes MOA

interferes with ergosterol and loses selective permeability of fungal wall

polyenes spectrum

broad most fungi

polyenes disadvantages

can interfere with host cholesterol

echinocandin MOA

inhibits chitin synthesis

echinocandin spectrum

broad most fungi

echinocandin disadvantage

embryotoxic cannot take while pregnant

what makes the perfect microbial drug?

selectively toxic

microbicidal (kills directly)

remains potent long enough to be effective

no resistance

easy delivery

reasonably prices

what does MIC assay do?

expose to drug concentrations

lower —> suseptible

higher —> resistant

why are viruses problematic?

they use host machinery to replicate and transcribe/translate

that would mean drugs targeting viruses would also target host cell machines

problems with antifungal drugs?

fungi and humans are eukaryotic, so this can be difficult to interfere with fungal cell processes without having adverse effects