Spotlight on specific therapies

Question 1

what are the 4 mechanisms of antibiotic resistance

Answer 1

• modifications of the antibiotic molecule
• decreased antibiotic penetration and efflux
• changes in target sites
• resistance due to global cell adaptations

Question 2

what are the 4 key elements of antibiotic stewardship

Answer 2

• measure antibiotic prescribing
• to improve antibiotic prescribing by clinicians and use by patients so that antibiotics are only prescribed and used when needed
• to minimize misdiagnoses or delayed diagnoses leading to the underuse of antibiotics
• to ensure that the right drug, dose, and duration are selected when an antibiotic is needed

Question 3

what is bactericidal?

Answer 3

kills sensitive organisms so that number of viable

Question 4

what is bacteriostatic?

Answer 4

inhibits growth of bacteria but does not kill them

Question 5

what are the different antimicrobial spectrum (coverage)

Answer 5

• narrow spectrum
• broad spectrum
• extended spectrum

Question 6

what is narrow-spectrum?

Answer 6

agent is active against a single species or limited group of pathogens

Question 7

what is broad-spectrum?

Answer 7

agent is active against a wide range of pathogens

Question 8

what is extended-spectrum

Answer 8

agent falls in between (intermediate)

Question 9

gram positive bacteria have…

Answer 9

• no outer lipid membrane
• number of peptidoglycan layers
• have a plasma membrane (bottom)

Question 10

gram negative bacteria have…

Answer 10

• has outer lipid membrane
• a single peptidoglycan layer
• have a plasma membrane (bottom)

Question 11

what are the mechanism of action of the beta-lactam antibiotics?

Answer 11

they interfere with bacterial cell wall synthesis by inhibit of bacterial transpeptidase which will inhibit peptidoglycan cross-linking making cell wall synthesis impossible

Question 12

what is penicillin V?

Answer 12

• narrow-spectrum antibiotic
• typically administered in an oral suspension
• adverse effects include GI upset, nausea, vomiting, diarrhea, and rash. In rare instances can cause severe hypersensitivity reactions
• considered the drug of choice for group A strep

Question 13

what is amoxicillin?

Answer 13

• extended-spectrum penicillin
• essentially a modified version of penicillin that results in greater activity against additional gram-negative bacteria
• generally well tolerated but can cause the same adverse effects as penicillin
• more palatable than penicillin V

Question 14

what is cephalosporins?

Answer 14

• a very large group of antibiotics
• different generations are used to define their antimicrobial spectrum

Question 15

cefadroxil

Answer 15

• first generation cephalosporin
• may be used if treatment failure with penicillin or in individuals with nonimmediate hypersensitivity to penicillin
• adverse effects include: GI upset, nausea, vomiting, diarrhea, hypersensitivity

Question 16

cephalexin

Answer 16

• first generation cephalosporin
• same adverse effect profile as cefadroxil and may also be used if treatment failure with penicillin or in individuals with nonimmediate hypersensitivity to penicillin

Question 17

what are protein synthesis inhibitors

Answer 17

antibiotics that inhibit protein synthesis in bacteria
- many ways like interfere with ability of bringing the correct amino acid, interfere with ability of peptidyl transferase to attach those amino acids together, or interfere with translocation process

Question 18

what are macrolides?

Answer 18

• inhibit peptidyl transferase which functions to link amino acids together in the growing peptide chain
• also interferes with translocation (movement of the nucleotide from the A position to the P position to allow for reading the next spot on the mRNA)
• Confers bacteriostatic activity

Question 19

What are azithromycin?

Answer 19

• an alternative for patients who are allergic to penicillin
• less likely than other macrolide antibiotics to interact with other drugs
• adverse effects: GI upset, nausea, vomiting diarrhea, rash, QTc interval prolongation (cardiac conduction abnormality)

Question 20

what are clarithromycin?

Answer 20

• an alternative for patients who are allergic to penicillin
• same adverse effect as axithromycin
• increases the levels of some common drugs like atorvastatin, simvastatin, and prednisone

Question 21

what are lincosamides?

Answer 21

• interfere with translocation but do not inhibit peptidyl transferase
• approx 4 times more likely to cause clostridium difficile infections compared to other antibiotics
• generally bacteriostatic but can be bactericidal at high doses

Question 22

what are clindamycin?

Answer 22

• an alternative for patients who are allergic to penicillin
• may be used for treatment in symptomatic patients with multiple, recurrent episodes of pharyngitis