Microreview7(Drugs And Vaccines)

Front 1

Name the major categories of beta lactam antibiotics.

Back 1

Penicillins/cephalosporins/monobactams/carbapenems

Front 2

What is the mechanism of action of all beta-lactam antibiotics?

Back 2

They bind to and inactivate transpeptidases, which are involved in bacterial cell wall synthesis.

Front 3

What is the difference between Pen G and V? What is the most adverse effect?

Back 3

Pen G is given I/V and Pen V is resistant to gastric acid, allowing it to be given orally.
Hypersensitivity reactions, up to 8%.

Front 4

Which bacteria are potentially suscepptible to Pen G?

Back 4

Gram positives.
Exceptions-Staph. aureus,) Neisseria, spirochetes and most anerobes

Front 5

Give a mneumonic aid for bacteria sensitive to Pen. G.

Back 5

SPANs
Spirochetes/gram Positives/Anerobes/Neisseria

Front 6

How does probenicid increase the half life of Pen G?

Back 6

It blocks active renal secretion of penicillin.

Front 7

Which penicillins are the semisynthetic(antipStaph) penicillins that are potentially more resistant to B- lactamases?

Back 7

Methicillin/Nafcillin/Oxacillin/Cloxacillin/Dicloxacillin.

(MCNOD)(Methicillin,Cloxacillin/Nafcillin/Oxacillin?Dicloxacillin

Front 8

What is the Jarisch-Herxheimer phenomenon?

Back 8

Worsening of symptoms(fever, headache, muscle pains) soon after Pen G treatment, due to released pyrogens from killed organisms.

Front 9

Which Penicillin class can be used to treat Pseudomonas aeruginosa?

Back 9

Carbenicillin/Piperacillin/Ticarcillin

Front 10

Do beta lactamase inhibitors such as clavulanic acid or tazobactam improve penicillin activity against penicillin resistant P. aeruginosa?

Back 10

No. Beta lactamase inhibitors do not really improve the activity of penicillin against Pseudomonas.

Front 11

Ampicillin or Amoxicillin can be used to treat which organisms?

Back 11

HELPS(H. influenzae/Enterococci/E. coli,/Listeria/Proteus/Salmonella

Front 12

Ampicillin and Gentamicin is the standard treatment for meningitis caused by L. monocytogenes. TRUE/FALSE

Back 12

TRUE.

Front 13

What are some potential problems with cephalosporins that contain N- methyl thiotetrazole side chains?

Back 13

Disulfram like reaction causing hypotension, nausea and vomiting when ingested with etanol and prolonged prothrombin time(PT) with risk of bleeds because of interference with Vit. K activity.

Front 14

Which cephalosporin antibiotics have the best coverage against P. aeruginosa?

Back 14

Cefipeme(4th gen) and ceftazidime(3rd gen).

Front 15

Which cephalosporin is often used for the treatment of community acquired meningitis? WHY?

Back 15

Ceftriaxome and cefotaxime because it can readily cross the blood brain barrier and covers most strains of Streptococcus pneumoniae and Neisseria meningitiditis(most common causes of adult community acquired meningitis)

Front 16

What is unique about cefoperazone?

Back 16

Although no longer available in the US, cefoperazone is unique in that it is 70% eliminated in the bile.

Front 17

Which cephalosporins are commonly used as prophylaxis for GI surgery. WHY?

Back 17

Cefoxitin, Cefazolin or cefmetazole because they have activity against anerobes.

Front 18

Are penicillins and cephalosporins effective against Mycoplasma pneumoniae?

Back 18

No. They do not have cell walls.

Front 19

Which beta lactam antibiotic is safe for the treatment of Gram neg organisms, such as pseudomonas in patients with penicillin allergies?

Back 19

Aztreonam(monobactams)

Front 20

What type of bacteria are susceptible to aztreonam?

Back 20

Aerobic, Gram-negative bacteria

Front 21

Why is imipenam, which has the broadest coverage of all the Beta lactam drugs, always given with cilastitan?

Back 21

Cilastitan is a dehydropeptidase inhibitor that inhibits metabolism of imipenam in the kidney. This prevents nephrotoxicity and increases the urine concentration of intact imipenam allowing for therapy of UTIs.

Front 22

What is the chief concern of having high plasma levels of imipenam?

Back 22

CNS toxicity/seizures.

Front 23

What are the advantages of meropenam over imapenam?

Back 23

Meropenam does not need to be administered with Cilastitan and causes fewer seizures.

Front 24

How do bacteria become resistant to B-lactam drugs?

Back 24

Production of beta lactamases mutations in penicillin binding proteins, or altered porins.

Front 25

Which drug is the treatment of choice for methicillin resistant S. aureus(MRSA) and what are its major side effects?

Back 25

Vancomycin. Nephrotoxicity, ototoxicity, thrombophlebitis and diffuse erythema due to histamine release.

Front 26

How do certain Gram + bacteria become resistant to vancomycin?

Back 26

By mutation of the terminal D-alanine-D-alanine sequence in in bacterial cell wall to which vancomycin binds. Vancomycin inhibits cell wall synthesis but it is not a B-lactam drug.

Front 27

What is the mechanism of action of bacitracin?

Back 27

Prevents dephosphorylation and thus regeneration of a phospholipid carrier needed for cell wall synthesis. Topical agent is too toxic for systemic use.

Front 28

Cycloserine is a second line agent for tbc. What is its mechanism of action. Does it have side effects?

Back 28

Analogue of D-alanine that prevents the formation of the D-ananyl-D-alanine dipeptide in cell wall synthesis. CNS toxicity: seizures, acute psychosis and neuropathy.

Front 29

What is the mechanism of action of fosfomycin which is used for UTIs?

Back 29

Inhibits enolpyruvate transferase, preventing the formation of N-acetylmuramic(NAM) acid.