Chemotherapy part 1 (1) Flashcards
1
Q
Ludwigs angina
- a serious, _____ or _____ infection of the floor of the mouth, usually occuring in adults with concomitant _____ infections
- may obstruct the airways, necessitating _____
- mixed infections: _____ and _____
- alpha hemolytic streptococci, staphylococci and bacteroides groups
- facial space infection with involvement of _____, _____, and _____ spaces
- external signs may include bilateral _____ facial edema around _____ and upper _____
- dysphagia, odynophagia, difficulty breathing, and pain
A
life threatening cellulitis connective tissue dental tracheotomy aerobes anaerobes submandibular sublingual submental lower mandible neck
2
Q
past and present
- US centers for disease control estimates that 90000-200000 deaths occur annually due to nosocomial infections
- staph aureus resistant to _____, _____, _____ due to specific genes
- bacteria cold transfer these resistant genes among themselves
- hospitals today are plagued with MRSA and VRE
- viral disease
A
penicillins
erythromycin
tetracycline
3
Q
future
drug resistance is becoming a worldwide concern
-gonorrhea and typhoid fever are becoming more difficult to treat
-TB and malaria are growing more resistant to Rx
-60% nosocomial infections are MDR
only 5 new classes of antibiotics in the past 40 years!
- _____ (linezolid)
- _____ (daptomycin)
- _____ (retapamulin
- _____ (dalfopristin)
- _____ (tigecycline)
- linezolid is most promised
- combination therapy to treat TB to avoid resistance
A
oxazolidinones lipopeptides pleuromutalins streptogramins glycylcyclines
4
Q
history of antibiotics
- 1900 paul ehrlich
- ‘Magic Bullet’
- salvarsan: fuchsin and mercury to treat _____
- sir alexander flemming: _____
domagk: _____ from ‘Prontosil’ - _____
A
syphilis
penicillium notatum (a fungus)
sulfonamides
red dye
5
Q
definitions
- _____: substances that act against or destroy infections (_____/_____/_____)
- antibiotics: substances produced by _____ that can destroy or suppress the growth or multiplication of bacteria to prevent the _____ of _____
- antimicrobials/antibacterial: _____ or _____ substances used to suppress growth or kill _____/ _____ cell organisms
- antivirals/antifungals/antiprotazoans/antihelminths
A
anti-infective agents fungal viral bacterial bacteria action bacteria natural synthetic bacteria single
6
Q
MOA of antibacterial action
- inhibition of _____ synthesis
- alteration of the _____
- inhibition of ribosomal _____ synthesis
- suppression of _____ synthesis
- inhibition of _____ synthesis
A
cell wall cell membrane permeability protein DNA folic acid
7
Q
inhibition of cell wall synthesis
- cell walls contain alternating _____ units, cross linked with _____ linkages
- bacterial enzymes termed _____ (PBP) catalyze the formation of the wall by incorporating new _____ strands
- _____ antibiotics competitively inhibit this final process, thus preventing a _____ cell wall forming
- internal osmotic pressure causes _____
- -_____ (amoxicillin; penicillin V)
- -_____ (cephalexin)
A
peptidoglycan amide penicillin binding proteins peptidoglycan beta-lactam rigid lysis penicillins cephalosporins
8
Q
alteration in cell membrane
- bacterial cell membranes contain a _____ component
- this maintains cell membrane integrity
- antibiotics such as polymyxin B displace _____ and _____ from the cell membrane and disrupt membrane
A
lipopolysaccharide
Ca++
Mg++
9
Q
inhibition of protein synthesis
- bacterial ribosomes have subunits such as _____ and _____ where proteins are synthesized
- antibiotics bind to the _____ site of these subunits and inhibit _____
- this inhibits binding of _____ to _____
- 30S: _____, _____
- 50S: _____, _____
A
30S 50S p peptidyl transferase tRNA mRNA tetracyclines aminoglycosides macrolides clindamycin
10
Q
inhibition of nucleic acid synthesis
- _____ of DNA, DNA _____, recombination and DNA repair occurs by _____ and _____ enzymes
- _____ and _____ inhibit these enzymes
- results: vacuoles, filamentation and cell lysis
A
supercoiling replication DNA gyrase topoisomerase fluoroquinolones metronidazole
11
Q
inhibition of folic acid synthesis
- humans fo not produce folic acid, it is available from _____ sources
- bacteria synthesize their own _____ from _____ (Para amino benzoic acid)
- PABA converts into _____ acid by enzyme _____
- _____ are structural analogues of PABA and block the conversion
- _____ and _____
–trimethoprim prevents eventual production of folic acid
A
dietary folic acid PABA dihydrofolic dihydrofolate reductase sulfonamides sulfamethoxazole trimethoprim
12
Q
antibiotic resistance
- give patient antibiotics and it goes into the bacteria which creates its own _____. it can throw antibiotic right out of the structure
- modifies the _____. creates an _____ to the antibiotic and it cannot be taken up
- formation of _____- can transmit genetic info (can transmit genetic code from one bacterial to another)
- bacteria which has a target where antibiotic would’ve acted requires a _____ for that target
- inactivate the drug through _____
A
efflux pump cell wall impermeable protein plasmids receptor drug-inactivating enzyme
13
Q
superinfections
-a _____ infection while patient is being treated for a _____ infection
–more likely with _____
–may also be opportunistic infections with fungi such as Candida albicans and histoplasmosia
may occur due to inhibition of normal flora such as _____ and _____
-often difficult to treat
-drug resistant microbes usually involved
-genetic messages (plasmids, transposons) transferred to new bacteria
A
new primary broad spectrum antibiotics clostridium difficile pseudomembranous colitis
14
Q
antibiotic adverse effects
- antibiotic teratology: FDA class B or C
- _____: genetic or acquired by drug use. _____, _____ may cause sudden syncope and cardiac arrest
- _____: reduced neutrophil counts with septicemia and shock. may be caused by _____ and _____
- superinfections: destruction of normal flora (diarrhea and pseudomembranous colitis)
- _____: CYP 450 induction or decreased GIT absorption of OC (loss of contraception)
- photosensitivity, stevens johnson syndrome, allergy and toxicity
A
long QT syndrome fluoroquinolones macrolides agranulocytosis sulfonamides penicillins oral contraceptives
