Antimicrobial Flashcards
What are examples of penicillins?
penicillin G, ampicillin
What are examples of cephalosporins?
ceftriaxone, ceftaroline
What is an example of monoactam?
azotreonam
What is an example of carbapenams?
imipenam
What is an example of trycylic glycopeptide?
vancomycin
What is an example is cyclic lipopeptide?
daptomycin
What is an example of tetracyclines?
tetracyline
What are examples of macrolides?
azithromycin, erythromycin
What is an example of lincosomides?
clindamycin
What are examples of streptogramins?
quinopristin, dalfopristin
what are examples of aminoglycosides?
gentamicin, tobramycin
What is an example of sulfonamides?
sulfamethoxazole
What are examples of quinolones?
ciprofloxacin, levofloxacin
What drug has its own group?
trimethoprim
What is selective toxicity?
kill or damage a microbe without damage to the host
What is therapeutic index?
- TI= LD50/ED50
- ratio of the toxic dose to the effective dose
LD must be large; ED must be low
What does -cidal mean in antibiotics?
kill bacteria
What does -static mean in antibiotics?
stop abcteria from growing; does NOT kill
What drugs are bacteriostatic?
- tetracyclines
- erythromycin
- chloramphenicol
What drugs are bacteriocidal?
- penicillins
- aminoglyocsides
- cephalosporins
What is the exception that can be either -cidal or -static?
sulfonamides
surf between cidal and static
Where would bacteriostatic and bacteriocidal agents be located on a graph?
bacteriostatic agents would be located above bacteriocidal agents
What group of drugs are beta lactams?
- penicillins
- cephalosporins
- monobactams
- carbapenems
What drugs play a role in cell wall synthesis?
- penicillins
- cephalosporins
- monobactams
- carbapenems
- vancomycin
What drugs play a type of role in DNA to RNA synthesis?
- quinolones: DNA gyrase, replication
- rifampin: RNA polymerase
- metronidazole: damage DNA
What drugs play a role in protein synthesis?
- tetracyclines
- aminoglycosides
- chloramphenicol
- macrolides (azithromycin, erythromycin)
What drugs play a role in the cell membrane?
- polymyxins
- daptomycin
Which drugs play a role in the production of folic acid?
- trimethoprim
- sulfonamides
PABA -> DHFA -> THFA
What are the reasons why a patient may not respond to therapy?
- misdiagnosis
- no infection
- do not complete full length of therapy
- patient self treatment of infection with antimicrobials that were not prescribed to them
What are some factors to consider when treating an infection?
- sensitivity of organism to drug
- appropriate dosage
- route of admin.
- duration of therapy
- special patient features
What is meant by “superinfection”?
when an antimcirobial migth disturb the ecologically balance leading to overgrowth of pathogenic microbes that are resistant to the antimicrobial agent
What is an example of something that can cause a superinfection?
C. Diff Albicans
What are the microorganisms that are most likely to cause a burn and traumatic/surgical wounds?
- staph
- strep
- pseudo. aeru
What are the microorganisms that are most likely to cause a skin infection?
- staph
- strep
- herpes
What are the microorganisms that are most likely to cause a wound infection?
- staph
- E. coli
- bact fragilis
What si the difference between the MIC and MBC?
- MIC: used more
- MBC: can be toxic
What si the goal of MIC to get rid of infection?
3-5 times more
What is the first choice of treatment for syphilis?
benzathine + penicillin G
What is the first choice of treatment for tuberculosis?
rifampin + isoniazid + pyrazinamide + ethambutol
What is the first choice of treatment for pneumonia?
piperacillin/tazabactam + tobramycin
Most antimicrobia drugs are excreted by what organ?
kidneys
What is creatinine clearance rate?
- measure renal function
- serve as guide to adjust dose
dose based on patients renal function
For hepatic function, which drug do you need to reduce the dosage for?
chloramphenicol
For hepatic function, which drug do you need to use with caution and have NO dosage adjustment?
clindamycin
How does the change in dose affect neonates (chloramphenicol)?
- low conc. of UGT which conjugates chloramphenicol; cleared by kidneys
- infants died from cardiovascular collapse, Gray Baby syndrome
- give lower dose
How does the change in dose affect neonates (sulfonamides)?
- displace bilirubin from albumin in the blood which can deposit in the brain
- contraindicated in neonates
How does the change in dose affect children?
- permanent dsicoloration of growing teeth of children
- can cause intracranial hypertension in infants and children
How does the change in dose affect CHF patients?
ticarcillin disodium/calvulanate potassium can cause edema and arrythmia
What dosage needs to be increased for infants/young children?
gentamicin
What drug causes the risk of hepatitis to increase with age?
isoniazid
What are the contradicted drugs for pregnancy and nursing?
- metronidazole
- sulfonamides
- antifolate drugs
- fluoroquinolones
- tetracyclines
What is the best combination for synergy?
2 drugs from different classes or have different mechanism of action
What are the mechanisms of antimicrobial resistance in pathogenic microbes?
- decrease drug uptake
- increase durg increase
- decrease affinity for site of action
What are the gram positive microorganisms?
- staph
- strep
- E. faecalis
- mono
What are the gram negative microorganisms?
- E. coli
- kleb
- pseudo
- H. influenzae
Which microorganisms are anaerobes?
C. diff and bacterio fraglis
What are the gram positive characteristics in regards to a membrane?
- lactamase outside
- thicker peptidoglycan wall
What are the gram negative characteristics in regards to a membrane?
- outer membrane with porin channel
- thin peptidoglycan layer
- lactamase inside
Penicillin targets what?
transpeptidase
important for cross linking
Fosphomycin inhibits what enzyme?
pyruvyl transferase
used in formation of NAM
Peptidoglycan is a target for what enzymes?
vancomycin and pentapeptide
What is the mechanism of action for penicillins and cephalosporins?
- inhibit peptidoglycan transpeptidase
- penicillin binding proteins (PBP)
- trigger autolysins
What are the chararcteristics of penicillin G?
- narrow spectrum
- penicillinase-sensitive
- used to treat trep and necrotize
What are the chararcteristics of dicloxacilin?
- narrow spectrum
- penicillinase-resistant
- used ot treat staph, skin infection and run of the mill
What are the chararcteristics of amooxicillin?
- broad spectrum
- penicillinase sensitive
- used ot treat H. influ, E. coli, mono, ear/URTI
What are the chararcteristics of ticarcillin?
- broad spectrum
- penicillin sensitive
- used to treat pseudo aeru and nocosomial
What are the chararcteristics of piperacillin?
- undergo renal clearance
- poor in absense of inflammation
What is the pharmacokinetics of penicillins?
conc. of drug acheived to treat meningitis, arthritis, endophthalmitis
What are the side effects of penicillins?
- NVD
- superinfection of GI tract: C. diff
- neurotoxicity: seizures, penicillin G inhibit GABA
- penicillin allergy
What are the mechanisms of resistance of penicillins, carbapenems, monobactam, and cephalosporins?
- changes in PBP
- tolerance: deficiency in autolytic enzymes
- changes in the porins (gram -)
- beta-lactamase
What are the drugs in cephalosporins?
- cefazolin: 1st gen
- cefoxitin: 2nd gen
- ceftriaxone: 3rd gen
- cefepime: 4th gen
- ceftaroline: 5th gen
What is cefazolin used to treat?
used to treat pro mira, E. coli, kleb pneu, staph/strep (PEKS)
What is cefoxitin used to treat?
used to treat haem influ, enter aero, neiss hono, PEK (HEN PEK)
What is ceftriaxone used to treat?
used to treat 2nd gen and acine calco, citro dive, entero cloa, serra marce, and GRAM -, meningitis
What is cefepine used to treat?
used to treat 3rd gen, strep, pseudo aeru, citro freu, seriosu G- nonsocomial infec.
What are the chararcteristics of ceftaroline?
used to treat 4th gen (besides pseudo aeru), acute bacterial infec., pneum
What are the side effects of cephalosporins?
DO NOT give to patients with history of severe penicillin reaction
What are carbapenems used to treat?
used ot treat G-, pseudo aeru, mono, serious nosocomial infections
What are the pharmacokinetics of carbapenems?
- primarily renally cleared
- imipenem hydrolyzed by dipeptidases
What are the side effects of carbapenems?
seizures, hypersensitivity reactions
What is the drug to give someone if they are allergic to penicillin?
aztreonam
What is monobactam used to treat?
used to treat G- (E. coli, kleb pneu, haemo influ, prot vulga, pseudo aeru)
What is the pharmacokinetic of monobactam?
renally cleared
What are he side effects of monobactam?
- GI upset
- phlebitis, pain at injection
- cross reactivity
- hypersensitivity reactions; , 15 of beta lactam allergic patients
What is the main drug for tricyclic glycopeptide?
vancomycin
What is the main drug for monobactam?
aztreonam
What is the mechanism of action for trycyclic glycopeptide?
- inhibitor of peptidoglycan synthase
- attaches to NAG and NAM; binds to D-ala-D-ala
- inhibitor of pentapeptide precursor and membrane carrier
What is trycyclic glycopeptide used to treat?
G+, MRSA, MRSE, both streps, coryne dipth, both entero faec, serious multi-drug resistant infections, C. diff
What are the pharmacokinetics of trycyclic glycopeptides?
- renally cleared
- can enter CSF with inflamed meninges
What are the side effects of trycyclic glycopeptides?
- ototoxicity: rare
- nephrotoxicity: uncommon
What are the mechanisms of tricyclic glycopeptide?
- changes alanine to lactate
- vancomytcine resistant enterococci
What is the drug for cyclic lipopeptide?
daptomycin
What is th mechanism of action for cyclic lipopeptides?
binds to cell membrane, forms pores
What is cyclic lipopeptide used to treat?
G+, MRSA, VRE
What are the pharmacokinetics of cyclic lipopeptides?
- renally cleared
- pulmonary surfactant inactivates it
- CANNOT be used for lung infections (ex: pneumonia)
What are the side effects of cyclic lipopeptide?
- myopathy
- rhabdomyolysis
What is the mechanism of resistance of cyclic lipopeptides?
treatment failure -> increase in MIC
What are the drugs for tetracyclines?
tetracycline, minocycline, doxycycline
What is the mechanism of action for tetracyclines?
- inhibit protein synthesis
- bind to 30S subunit
- prevent attachment of bacteriostatic (TEC)
What are tetracyclines used to treat?
mycoplasma pneu, cutibact acnes, chlamydia, strep
What are the pharmacokinetics of tetracyclines?
- limited CNS penetration
- doxycycline primarily fecally eliminated -> with renal failure
What are the side effcts tetracyclines?
- contraindicated during pregnancy
- discoloration of teeth and inhibit bone
- photosensitivity
- superinfection -> C. diff, C. albicans
What is the mechanism of resistance for tetracyclines?
- plasmid-determined resistance: decrease influc and increase efflux
- ribosomal change
What is the drug for glycylcyclines?
tigercycline
What is the mechanism of action for glycylcyclines?
- bind to bacterial 30S ribosomal subunit
- bacteriostatic
What are the characteristics of glycylcyclines?
- broad spectrum
- used to treat: G+, G-, MRSA, VRE, PRSP, skin infections
What are the side effects of glycylcyclines??
- increase mortality risk, limit use for multi-resistance
- contraindicated in pregnancy, superinfection
What are the drugs for macrolides?
- erythromycin
- azithromycin
- clarithromycin
What is the mechanism of action for macrolides?
- inhibit protein synthesis
- binds ot peptidyl-tRNA region on 50S subunit
- bacteriostatic
What are the characteristics of macrolides?
- used to treat chlamydia, H. influenzae, M. catarrhalis, URTI, pneumonia, otis media
- broad spectrum
What are the side effects of macrolides?
- prolong the QTc interval
- rash
- hepatits
- embryotoxic
What is the mechanism of resistance of macrolides?
methylation of the 23 rRNA binding site, prevents binding
What is the drug interaction of macrolides?
erythtromycin> clarithromycin, inhibit CYP3A4
What are the characteristics of chloramphenicol?
- binds to 50S subunit
- bacteriostatic
- bactericidal for meningitis
What is chloramphenicol used to treat?
haemo influen, neiss meningi, strep, rickett rickett
What are the side effects of chloramphenicol?
- anemia
- gray baby syndrome
What are the drugs for lincosamides?
- clindamycin
- Ca-mrsa
- CDAD
What is the mechanism of action of lincosamides?
binds to 50S ribosome subunit, bacteriostatic
What are lincosamides used to treat?
Ca-mrsa, B lactam allergy, strep, clostri perfri, lung abscess
What are the side effects of lincosamides?
CDAD, diarrhea, rash, fever, neutropenia
What is the mechanism of resistance for linosamides?
methylation of the 23rRNA binding site, prevents binding
What are the drugs for streptogramins?
quinopristin, dalfopristin
What is the mechanism of action for streptogramins?
binds to 50S subunit, bactericidal
What are streptogramins used to treat?
primary G+, entero faec (VRE), MRSA, strep, PRSP, osteo, endo
What are the side effects of streptogramins?
arthralgias, myaglias, pain, phlebitis at infusion site
What is the mechanism of resistance for streptogramins?
ribosomal methylase, acetyltransferase
What are the drugs for aminoglycosides?
gentamicin, amikacin, tobramycin
What is the mechanism of action for aminoglycosides?
- inhibit protein synthesis, bind to 30s subunit
- bactericidal
- conc. depend. killing
- synergistic with beta-lactams
What are aminoglycosides used to treat?
- primary for aerobic G-, pseudo aeru, both entero, serra marce, prot vulga, kleb pneu, listeria mono, serious G- nosocomial infections
- combined with beta lactam
What is the pharmacokinetics of aminoglycosides?
- primarily renally cleared
- polar -> decrease distribution
What are the side effects of aminoglycosides?
nephrotoxicity, ototoxicity, neuromuscular blackade, teratogen, myelosuppression
What is the mechanism of resistance of aminoglycosides?
- decrease in porin permeation and ribosomal binding
- enzymatic inactivation: acetyltransferase and phosphotransferase
What is the drug for macrocylic antibiotic?
fidaxomicin
What is the mechanism of action for macrocylic antibiotic?
binds to sigma unit of RNA polymerase, inhibits protein synthesis
What is macrocylic antibiotics used for?
C. diff, CDAD
What are the side effectsof macrocylic antibiotic?
abdominal pain, GI hemorrhage, BMS
What is pharmacokinetic of macrocylic antibiotic?
very little systemic absorption, high fecal conc.
What is the drug for sulfonamides?
sulfamethoxazole
What is the mechanism of action for sulfonamides?
- inhibition of dihydropteroate synthase
- decrease biosynthesis of DNA, RNA, AA, bacteriostatic
What are sulfonamides used to treat?
- broad spectrum
- strep, both haem, nocard astero, E. coli, kleb granu, chlamydia, UTI
Dihydropteroate synthase is inhibited by?
sulfonamides
Dihydrofolate reductase is inhibited by?
trimethoprim
What are the side effects of sulfonamides?
rash, sulfa allergy, SJS, TEN, kernicterus (newborn encephalopathy)
What are sulfonamides used to treat?
conjunctivitis, burns, Ag sulfadiazine
What are the pharmacokinetics of sulfonamides?
- renally cleared
- NAT and UGT substrate
- inhibit CYP2C9 -> increase warfarin AUC
What are the mechanism of resistance for sulfonamides?
- DO NOT biosynthesize folic acid
- increase PABA production
- dihydropteroate synthase, low affinity for sulfa
- decrease sulfa permeability
What are the mechanisms of action for trimethoprim/sulfamethoxazole?
- DHFRI, DHPSI, synergism
- bacteriostatic, can be bactericial in blood; can be both in urine
What is trimethoprim/sulfamethoxazole used to treat?
MRSA, E. coli, UTI, prostatitis
What are the side effects of trimethoprim/sulfamethoxazole?
BMS, rash, hemolytic anemia
What is the mechanism of resistance of trimethoprim/sulfamethoxazole??
decrease DHFR afiinity, decrease cell permeation, DHFR overproduction
What are the drugs for quinolones (floxacin)?
ciprofloxacin, levofloxacin, moxifloxacin
What are the mechanisms of action for quinolones (floxacin)??
inhibit topoisomerase 2, inhibit DNA replication
What are the mechanisms of action for quinolones (floxacin)??
inhibit topoisomerase 2, inhibit DNA replication
What are the side effects of quinolones?
tendonitis, myasthenia gravis
What are the drug interactions of quinolones?
- celation, Al, Mg, Fe, Ca
- inhibit CYP1A2, increase caffeine
What is the mechanism of resistance of quinolones?
- increase efflux
- decrease influx
- mutation in topoisomerase 2 or 3, decrease binding