Drugs to Memorize — Antibiotics – Flashcards
Unlock all answers in this set
Unlock answersquestion
Name 5 mechanisms for antibiotics.
answer
1) inhibit cell wall synthesis 2) inhibit protein synthesis 3) inhibit folic acid synthesis 4) inhibit DNA / RNA synthesis 5) distinct mechanisms
question
Name 4 categories of cell wall inhibitors.
answer
1) penicillins 2) cephalosporins 3) carbapenems 4) other
question
Name 9 categories of protein synthesis inhibitors
answer
1) aminoglycosides 2) macrolides 3) tetracyclines 4) chloramphenicol 5) lincosamides 6) ketolides 7) mupirocin 8) linezolid 9) streptogramins
question
Name 2 classes of folic acid synthesis inhibitors
answer
1) sulfonamides 2) trimethoprim
question
Name 3 classes of DNA / RNA synthesis inhibitors
answer
1) fluoroquinolones 2) lipopeptides 3) metronidazole
question
Name 3 drugs with distinct mechanisms
answer
1) nitazoxanide 2) tinidazole 3) rifaximin
question
Name 4 sub-classes of penicillins
answer
1) natural penicillins 2) penicillinase-resistant penicillin 3) aminopenicillin 4) antipseudomonal penicillin
question
What two sub-classes of penicillins are effective exclusively on G+ bacteria?
answer
natural and penicillinase-resistant penicillins
question
Which is oral and which is iv -- penicillin G and penicillin v?
answer
penicillin G -- "gold standard" = iv penicillin v -- oral
question
Name an aminopenicillin?
answer
ampicillin or amoxicillin
question
Name an antipseudomonal penicillin?
answer
ticarcillin or piperacillin
question
Are the penicillins bacteriocidal or bacteriostatic?
answer
bacteriocidal
question
How do pencillins work to kill bacteria?
answer
bind to transpeptidase enzyme (PBP) and blocks cross-linkage of NAM and NAG in bacterial cell wall
question
What is the main resistance mechanisms for penicillins?
answer
Beta-lactamases
question
What are two possible drug interactions to keep in mind with penicillins?
answer
1) lowers effectiveness of birth control 2) ineffective if combined with drugs that are bacteriostatic; bacteria must be replicating for penicillins to work
question
What is often prescribed along with amoxicillin?
answer
B-lactamase inhibitor, clavulanic acid
question
What is often prescribed along with ticarcillin?
answer
B-lactamase inhibitor, clavulanic acid
question
What is often prescribed along with piperacillin?
answer
B-lactamase inhibitor, tazobactam
question
What is route for antipseudomonal penicillins?
answer
iv
question
What kind of bacteria are cephalosporins used for?
answer
G- bacteria especially Klebsiella
question
What is the best antibiotic for Klebsiella?
answer
cephalosporins
question
Name 2 carbapenems
answer
imipenem and meropenem
question
What is the route for carbapenems?
answer
iv
question
Name a specific cephalosporin
answer
cefazolin, ceftriaxone
question
Cephalosporins are bacteriocidal or bacteriostatic?
answer
bacteriocidal
question
Carbapenems are bacteriocidal or bacteriostatic?
answer
bacteriocidal
question
Imipenem is often given along with what other drug?
answer
cilastatin, which inhibits enzyme that degrades imipenem
question
What kind of drug is methicillin?
answer
penicillinase-resistant penicillin
question
What is the mechanism for vancomycin?
answer
cell wall inhibition
question
What bacteria is vancomycin used for?
answer
Gram positive bacteria
question
Is vancomycin bacteriostatic or bacteriocidal?
answer
bacteriocidal
question
How specifically does vancomycin work?
answer
binds to D-ala-D-ala portion of cell walls, blocking cell wall polymerization and cross-linking
question
What bug is the drug cycloserine used for?
answer
mycobacterium TB
question
Is cycloserine bacteriocidal or bacteriostatic?
answer
bacteriocidal
question
What is the drug polymixin B used for?
answer
Gram- bacteria except for Proteus
question
Is polymixin B bacteriocidal or bacteriostatic?
answer
bacteriocidal
question
How specifically does polymixin B work?
answer
detergent that disrupts lipoproteins in bacterial cell walls, increasing membrane permeability
question
Name 2 aminoglycosides
answer
amikacin, gentamicin
question
What is mechanism for aminoglycosides?
answer
binds to bacterial 30s subunit; interferes with formation of complex. and causes ribosome to separate from the mRNA
question
What tissue(s) is toxicity to aminoglycosides seen?
answer
eyes and kidneys
question
What are resistance mechanisms for aminoglycosides?
answer
alterations in receptor proteins on ribosomes; enzymatic alteration of AGs by the bacteria
question
What bacteria are aminoglycosides used to treat?
answer
G-
question
What is route for aminoglycosides?
answer
IV
question
Name 2 macrolides
answer
erythromycin, clarithromycin and azithromycin
question
What is important to remember about erythromycin?
answer
CYP450 inhibitor and can prolong the QT interval
question
What is mechanism for macrolides?
answer
binds to 50S subunit and prevents translocation of incoming AA from the A site to the P site
question
What adverse effect(s) are associated with erythromycin?
answer
GI distress and therefore should be taken with food; CYP inhibition
question
What is the resistance mechanism for macrolides?
answer
methylation of the 50S subunit or enzymatic ability to destroy the drug
question
What is important to remember about tetracyclines?
answer
can be inhibited by chelation with milk; take on an empty stomach
question
What kind of bacteria are tetracyclines used for?
answer
G- and G+
question
Name 2 tetracyclines
answer
-tetracycline -doxycyclin
question
Are tetracyclines bacteriocidal or bacteriostatic?
answer
bacteriostatic
question
What is the mechanism of action for tetracyclines?
answer
inhibit protein synthesis through reversible binding to 30S subunit; prevents binding of new incoming AAs
question
Which tetracyline is best for patients with renal dysfunction?
answer
doxycycline
question
What is resistance mechanism for tetracyclines?
answer
efflux / pumped out of the cell (in G+)
question
What is the drug chloramphenicol used for?
answer
anaerobic bacteria
question
Is chloramphenicol bacteriocidal or bacteriostatic?
answer
bacteriostatic
question
What is complication is patients with hepatic disease on chloramphenicol?
answer
gray color, "gray baby"
question
Clindamycin is what kind of drug?
answer
lincosamide
question
What is mechanism of action for chloramphenicol?
answer
binds to 50S subunit and blocks linkage of incoming AAs; interferes with peptidyl transferase
question
Name an important lincosamide
answer
clindamycin
question
Clindamycin is used to treat what kind of bacteria?
answer
anaerobic
question
What is the route for clindamycin?
answer
topical
question
Is clindamycin bacteriocidal or bacteriostatic?
answer
bacteriostatic
question
What is the mechanism of action for clindamycin?
answer
binds to 50S subunit and prevents translocation of the incoming AA from the A site to the P site
question
What is 1 example of a ketolide?
answer
telithromycin
question
What are ketolides / telithromycin used to treat?
answer
MDR streptococci
question
What is mechanism of action for telithromycin?
answer
binds to 2 location on the 50S subunit; resistant to mutations
question
What is the route for mupirocin?
answer
topical
question
What is brand name for mupirocin?
answer
Bactroban
question
What is mechanism of action for mupirocin?
answer
inhibits the tRNA that transports isoleucine
question
What is mechanism of action for linezolid?
answer
binds to 50S subunit and prevents formation of the 70S complex
question
What is the target organism of streptogramins?
answer
VRA and MRSA
question
Name an example of a streptogramin
answer
quinupristin / dalfopristin (given together)
question
What is the mechanism for quinupristin / dalfopristin?
answer
quin -- blocks late phases of protein synthesis dalf -- inhibits early phases of protein synthesis
question
Name 2 drug classes of folic acid synthesis inhibitors?
answer
1) sulfonamides 2) trimethoprim
question
Name an example of a sulfonamide?
answer
sulfamethoxazole -- they all begin with "sulfa"
question
Are sulfonamides bacteriostatic or bacteriocidal?
answer
bacteriostatic
question
Is trimethoprim bacteriostatic or bacteriocidal?
answer
bacteriostatic
question
What is the mechanism of action for sulfonamides?
answer
interfere with the 1st step of folic acid synthesis -- compete with para-aminobenzoic acid and inhibit dihydropteroate synthetase
question
What is the mechanism of action for trimethoprim?
answer
interfere with the 2nd step of folic acid synthesis -- inhibits dihydrofolate reductase (DHFR)
question
Trimethoprim -- take with or without food?
answer
without -- food may inhibit absorption
question
Name 2 fluoroquinolones
answer
ciprofloxacin, moxifloxacin (ends in -floxacin)
question
Are fluoroquinolones bacteriocidal or bacteriostatic?
answer
bacteriocidal
question
What is mechanism for fluoroquinolones?
answer
inhibits DNA gyrase and DNA topoisomerase and therefore prevents DNA from replicating
question
Name 1 lipopeptide
answer
daptomycin
question
Is daptomycin bacteriocidal or bacteriostatic?
answer
bacteriocidal
question
What is the mechanism of action for lipopeptides / daptomycin?
answer
rapidly depolarizes the cell membrane
question
What is another name for metronidazole?
answer
Flagyl
question
What is the target of metronidazole?
answer
anaerobic bacteria especially in meningitis
question
What is the mechanism of action for metronidazole?
answer
the enzyme pyruvate ferridoxin oxidoreductase generates ferredoxin which reacts with the drug and generates toxins
question
What is the target for nitazoxanide?
answer
inhibits electron transfer reaction
question
What is ADE associated with metronidazole?
answer
mutagenic and possibly carcinogenic
question
What is mechanism of action for tinidazole?
answer
damages DNA and inhibits DNA synthesis
question
What is the name of a drug that inhibits mRNA synthesis by binding to RNA polymerase?
answer
rifaximin
question
Name 3 anti-mycobacterials?
answer
rifampin, isoniazid and ethambutol
question
What is mechanism for rifampin?
answer
inhibits the bacterial RNA polymerase
question
What is the mechanism for isoniazid?
answer
inhibits components of the mycobacterial cell wall
question
What is the mechanism for clofazimine?
answer
inhibits RNA polymerase
question
Why are there many drug interactions associated with rifampin?
answer
rifampin induces drug metabolism and binds to plasma proteins
