Flashcards in Antimicrobial agents Deck (11):
1. 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.
2. What is the therapeutic toxicity ?
This is the ratio of toxic dose to therapeutic dose.
3. 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
4. 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.
5. 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.
6. 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.
7. What are the problems when targeting viral infections ?
They replicate only in living cells of the body. They have a highly specific host range.
8. What are the two targets for anti viral drugs ?
1. Critical stages in the life cycle
2. Synthesis of the specific nucleic acids
9. 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.
10. 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.