Chap 24 Flashcards
(24 cards)
Erlich
“salvarsan” an arsenic derivative that killed the causative agent of syphilis
Domagk
“prontosil” - active against staphylococci, streptococci, and other G+ bacteria
Fleming
Penicillium mold from which penicillin was extracted
antibiotic
a substance produced by few bacterial or fungal species that inhibits or kills other microorganisms
synthetic
manmade
semisynthetic
a chemical substance synthesized from natural and man made components used to treat a disease
antimicrobial spectrum
the range of antimicrobial drug action
broad spectrum
useful for treating many groups of microorganisms, including G+ and G- bacteria
narrow spectrum
useful for a restricted group of microorganisms
5 major targets for antibacterial agents
- cell wall synthesis
- cell membrane
- protein synthesis
- nucleic acid synthesis
- folic acid metabolism
Folic acid metabolism
sulfonamides
Cell membrane
polymyxin B
Protein synthesis
- aminoglycosides
- chloramphenicol
- tetracyclines
- macrolides
- clindamycin
- streptogramins
- oxazolidinones
Nucleid acid synthesis
DNA: quinolones
RNA: rifampin
Cell wall synthesis
- Penicillin
- cephalosporins
- vancomycin
- bacitracin
- carbapenems
- isoniazid
- ethambutol
Sulfa drugs
inhibit folic acid synthesis due to competitive inhibition
synergistic
stronger together than alone
Bactrim
sulfamethoxazole combined with trimethoprim
Isoniazid
only on mycobacterium
-inhibits cell well synthesis by inhibiting production of mycolic acid
Quinolones
blocks DNA synthesis in G+ and G-
- UTI, gonorrhea, chlamydia, GI
- Cipro safe for adults but affects cartilage development
Beta Lactam class
targets PEP, typically G+
- commonality is a beta lactam nucleus
- penicillin is bacteriacidal (immediately kills it)
Disadvantages to penicillin
- anaphalactic reaction
- penicillin resistant bacterial species which neutralize or inactivate penicillin
Semisynthetic penicillins
modifications of natural penicillin by introducing different side chains
- extend the spectrum of antimicrobial activity and help reduce microbial resistance
- more resistant to penicillinases
Amoxicillin/Augmentin
amoxicillin used with clavulanic acid, inactivates penicillinase
