Antibiotics Flashcards
Mechanism of action of beta-lactams
Bind to pencillin binding protein on the cell wall
Subclasses of beta-lactams
Penicillins, cephalosporins, carbapenems
Mechanism of action of macrolides
Bacteriostatic - interferes with protein synthesis by ribosomal binding
Names of macrolide antibiotics
Erythromycin
Azithromycin
Clarithromycin
When to use macrolides?
Penicillin allergic patients for staph and strep. Also used in atypical pneumonia.
Name the tetracyclines
Oxycycline
Doxycycline
Tigecycline
Mechanism of action of tetracyclines
Bacteriostatic - inhibit tRNA binding to ribosome. Used in resp tract and soft tissue infections
Also can be used in penicillin allergic where macrolides have side effects.
Activity against atypical pathogens
How do trimethoprim and co-trimoxazole work?
Block synthesis of bacterial nucleotides in folic acid/nucleotide synthesis pathway
What can you use trimethoprim and co-trimoxazole for?
Gram negative and gram positive
What is co-trimoxazole used for
it is a combo of trimethoprim and sulfamethoxazole
treatment and prophylaxis of pneumoncystis jirovecii pneumonia, stenotrophomonas maltopihilia infection and nocardiosis.
can have severe side effects - steven johnsons syndrome and bone marrow suppression
Name the quinolones
Ciprofloxacin
Levofloxacin
Moxifloxacin
How do quinolones work?
Inhibit DNA gyrase (enzyme which supercoils bacteria)
What are quinolones used for?
Generally for gram negative, weaker against gram positive. Levo and moxi have better gram positive cover
Name the aminoglycosides
Gentomycin
Amikacin
Netilmicin
Tobramycin
How do aminoglycosides work?
Interfere with ribosome reading mRNA
What are aminoglycosides used for?
Prodominately against gram negative
Not active against streptococci but work synergistically with penicillins
Mainly used in serious sepsis
Side effects of aminoglycosides?
Potential for 8th nerve and renal toxicity. Have to measure serum levels
