Antimicrobial agents Flashcards
- What is selective toxicity ?
Selective toxcicty is when a drug has a highly specific action on the pathoge but has a minimal effect on the host.
- What is the therapeutic toxicity ?
This is the ratio of toxic dose to therapeutic dose.
- Name the 5 main modes of action that the drugs itefere with pathogens.
- Cell wall synthesis
- Protein synthesis
- Nucleic acid synthesis
- membrane integrity
- metabolic pathways
- What would be the selective toxicity for drugs against bacteria ?
The targetting of pg synthesis. Targetting the ribosome 30s 50s. Enzymes dna gyrase and topionmerase IV. Synthesis of folic acid and the cell membrane of bacteral cells.
- Why do anti fungal agents have a low therapeutic index ?
Fungal infections have the same eukaryotic structure as human cells meaning that the side effects can be bad.
- Name the two main ways anti fungals attack infections.
Cell wall; inhibition of the synthesis of Glucan. Cell membrane; Ergostrol and the synthesis of it.
- What are the problems when targeting viral infections ?
They replicate only in living cells of the body. They have a highly specific host range.
- What are the two targets for anti viral drugs ?
- Critical stages in the life cycle
2. Synthesis of the specific nucleic acids
- Name examples of beta lactam drugs and their functions.
Penicillin, cephalosporins, carapenems and monnobactems. The inhibit the crosslinking of pg via enzymes. Binds to 50s ribosomal units.
- What drugs target the protein synthesis in bacteria and how ?
Macrolides e.g erythromycin. They bind to the 50s ribosome and cause peptide chains to dissociate from the ribosome. They are bacteriostatic.
- Name the six main stages of the viral life cycle that anti viral agents will exploit.
- adsorption onto cell surfaces
- Uptake into the host cell
- uncoating of the genome
- macromolecular synthesis
- assembly
- release
