Micro Drugs Flashcards
Cycloserine
Antibiotic- Analog of d serine, will be incorporated into tetra peptides that are attached to the nam molecule. And will inhibit the cross linkage.
Bacitracin
it attaches to the carrier molecule so that the carrier molecule can’t pick up a new precursor of nam and nag molecule.
Glycopeptides
inhibits the growht fo the cell wall of bacteria. Vancomycin
not effective against Gram -ve because its large size doesn’t allow penetration into the cell.
altered target is a common resistance mechanism
Beta Lactams
penicillins and cyclosporins penicillin has a 5 member ring and cephalosporins have a six member ring they attach to the transpeptidases so that crosslinking cannot occur
not effective against mycoplasmas or mycobacteria because they lack cell wall or cell wall is impenetrable.
drug inactivation occurs very commonly, altered uptake and altered target is also common
Benzyl penicillin
natural penicillins 1st generation
Methicillin
penicillinase resistant penicillins made to resist the penicillinases that bacterias produce
Ampicillin
aminopenicillins- 3rd generation, devised to resist acidic ph so you can take it orally
Piperacillin
4th generation, same as ampiciliin but has an extended spectrum also active against some gram negative bacteria.
Aminoglycosides
induce codon misreading- binds irreversibly to the 30 s subunit which causes the misreading. this means it is bacteriocidal.
Streptomycin
not effective against Anaerobes because oxidative phosphorylation is absent in anaerobes
drug inactivation is a very common resistance mechanism, altered uptake is common, and altered target rare or occurs infrequently.
tetracyclines
binds reversibly to the 30s subunit which makes it bacteriostatic, blocks binding of aminoacylated tRNA
Drug inactivation is a common resistance mechanism, altered uptake is an uncommon mechanism.
macrolides
erythromycin binds to 23 s and affects polypeptide elongation. ihibits transpeptidation and translocation
Lincosamides
will block aminoacylated tRNA from actually attaching to the mRNA and prevents polypeptide formation. target binding at A and P sites
Streptogramins
cynacid, dalphopristine, they prevent peptide bond formation. Chloramphenicol
Quinolones
Target site is DNA replication, Binds both the alpha subunit DNA gyrase and topoisomerase IV which inhibits DNA synthesis
Rifampin
Targets RNA synthesis- binds to Beta subunit DNA dependant RNA polymerase complex and inhibits transcription of mRNA. Is a little toxic to us.
Nitroimidazoles
not effective against aerobes becuase it requires activation by flavodoxin which is absent in aerobes.
Sulfamethoxazole and Trimethoprim
are metabolism and nucleic acid inhibitors, they act synergistic to prevent formation of tetrahydrofolic acid. Trimethoprim inhibits dihydrofolate reductase and Sulfa inhibits dihydropteroate synthetase prevents conversion to dihydrofolic acid.
clavulanic acid
is a beta lactamase inhibitor that you give with penicillin to prevent it being broken down.
Polyenes
Direct membrane damage to fungus. these are broad spectrum fungicide
Amphotericin B
broad spectrum fungicide, causese direct damage to membrane.
5- FC
is a nucleic acid synthesis inhibitor, it can either be incorporated into RNA inhibtion of protein synthesis or can inhibit thymidylate sythetase and inhibit DNA synthesis
Azoles
Fluconazole, inhibits aldosterone synthesis so you can make ergosterol
Allylamines
lamisil- terbinafine, inhibits squaline epoxidase which means there is an accumulation of squaline and no lanosterol or ergostero formed.
Echinocandins
Beta glucan synthesis inhibitors, Caspofungin, Block the B-D-glucan syntheatase, works for Active candida and Aspergillus but not C. Neoformans.
