Pharmacology of Antibiotics Flashcards
Antibacterial Chemotherapy Targets
Bacterial cell walls
Bacterial ribosomes
Bacterial folate metabolism
Bacterial DNA gyrases
Antibacterials vs antibiotics
Antibiotics are antibacterials that are produced by an organism to attack other organisms (e.g. penicillin) while antibacterials are more of an umbrella
Beta lactam ring
Feature of penicillins
can be a weakness and be targeted by bacteria since it is unstable
Mode of action of penicillins
Target bacterial cell wall synthesis by binding irreversibly to the transpeptidase which cross links peptidoglycans in the bacterial cell wall
Thus it is only effective against dividing organisms as division requires cell walls synthesis, leading to lysis
Is penicillin bactericidal (also what is bactericidal)
Penicillins are bactericidal
They cause lysis of the bacteria
Beta-lactamase
Enzymes produced by bacteria that cause cleavage in the beta lactam rings
Note that some penicillins are resistant to beta lactamases
Clavulanic acid
An acid that is included with some agents to inhibit the beta lactamases
Immunogenic
Relating to or denoting substances able to produce an immune response.
Penicillin allergies
Penicillin is immunogenic so about 10% of patients treated with it can develop allergies
Cephalosporins
Beta-lactam antibiotics that act in a very similar way to penicillin
Do not prescribe them to patients who are allergic to penicillin as a small percentage of them would also be sensitive to cephalosporins
Glycopeptides
Antibacterials used against very resistant bacteria like MRSA
Inhibit bacterial cell wall synthesis by inhibiting the growth of the peptidoglycan chain
Are glycopeptides bactericidal
Yes (mostly)
Example of a glycopeptide
Vancomycin
Tetracyclines
Antibacterials that inhibit protein synthesis by binding to the 30S subunit of bacterial ribosomes and preventing tRNA from binding at the A(cceptor) site
Actively accumulate in bacterial cells
Have decreased use due to resistance
Bacteriostatic
Prevents the growth of bacteria