Kaplan-4 (Anitmicrobials)

Question 1

What is the DOC of treating listeria?

Answer 1

Ampicillin

Question 2

What is the preferred antimicrobial for treating H.pylori and B. Burgdofery

Answer 2

Amoxocillin

Question 3

What are the drugs that are B-lactamase resistant?

Answer 3

Nafcillin, Methicillin, oxacillin. They treat Gram(+), staphylococci but not MRSA, there is no B-lactam useful for MRSA

Question 4

What is the drug that blocks secretion of penicillin, increasing plasma levels and increasing half-life?

Answer 4

Probenecid. (Decreases clearance)

Question 5

what are the 1st generation Cephalosporins?

Answer 5

Cefazolin, cephalexin

Question 6

What are the 2nd gen ceph?

Answer 6

Cefotetan, Cefaclor, Cefuroxime

Question 7

What are 3rd gen ceph?

Answer 7

Ceftriaxone, and cefotaxime. Treats N. Gonorrhea and crosses BBB, hence can be used in the empiric treatment of meningitis.

Question 8

What do we give patients that are allergic to Penicillin?

Answer 8

For Gram +: Macrolides

For Gram -: Azreonam, aminoglycosides; SMX-TMP, Floxacin

Question 9

What drugs are indicated for life threatening infections pending cultures results?

Answer 9

Imipenem/Meropenem. Empiric management, same as penicillin ; resistant to beta-lactamases. They have a large spectrum.

Question 10

What drug must be administered with Imipenem?

What is a major SE of Imipenem?

Answer 10

Cilastatin; because cilastating is a renal dihydropeptidase inhibitor preventing formation of nephrotoxic metabolite.

SE: seizures

Question 11

What is the MOA of vancomycin?

Answer 11

Binding to D-ala-D-ala on pentapeptide to inhibit transglycosylation, preventing elongation of peptidoglycan chains.

DOC: MRSA, Enterococci, C.Diff (back up)

Question 12

Altered peptidoglycan structure (D-ALA-D-LAC) confers resistance to what medication?

Answer 12

Vancomycin

Question 13

What are SE of Vancomycin?

Answer 13

Histamine release: “red-man / red-neck” syndrome.
Ototoxicity
Nephrotoxicity.

Question 14

What kind of drugs do you treat immunocompromised pts with gram (-) aerobe infections?

Answer 14

Bactericidal drugs, can’t give bacteriostatic. Aminoglycosides cause misreading of the codon, hence why they are bactericidal. (for Step-1, it is the only bacterial protein inhibitor that is bactericidal)

Question 15

What bacteria are resistant to aminoglycosides?

Answer 15

Anaerobes because aminoglycosides are bactericidal, accumulated intracellularly via ocygen dependent uptake, so anaerobes innately resistant.

Question 16

What are the Aminoglycosides?

Answer 16

Gentamicin, Amikacin and Streptomycin.

Question 17

What are the SE of aminoglycosides?

Answer 17

Similar to Vancomycin , nephrotoxicity, otoxicity, but it is different from vanco cause it causes neuromuscular blockade due to decrease Ach release.

(Vanco causes histamine release “Red neck” which is different than aminoglycosides, also vanco is only for Gram (+) bugs)

Question 18

What is the preferred drug for treating syphillis and back up drug?

Answer 18

Penicillin G

Back up: tetracyclines (Doxycycline and minocycline)

Question 19

SE of Tetracyclines?

Answer 19

• Tooth enamel dysplasia and possible decrease of bone growth.
• Phototoxicity
• Liver dysfunction during pregnancy

Question 20

What is the cause of Grey Baby syndrome?

Answer 20

Its cause neonates lack glucuronyl transferase, and chloramphenicol is metabolized via hepatic glucuronidation; Hence we have to decrease dose in liver dysfunction and neonates.

SE: it also causes aplastic anemia.

Question 21

What can we treat Legionella pneumophila with?

Answer 21

Macrolides: Erythromycin / Azithromycin / Clarithromycin

Question 22

What class of drugs inhibit dihydropteroate synthetase?

Answer 22

Sulfonamides

Question 23

What class of drugs inhibit dihydrofolate reductase?

Answer 23

Trimethoprim and Pyrimethamine

Question 24

What do we use to treat Pneumocystis Jiroveci and Toxoplasmosis gondii?

Answer 24

TMP-SMX

Back-up for Pne. Jiro. : Pentamidine or Atovaquone

Question 25

What are MOA of sulfasalazine? What does this drug treats?

Answer 25

Sulfasalazine is a prodrug used in Ulcerative colitis and rheumatoid arthritis. This drug is composed of 5-ASA double bonded to sulfa pyridine (SP)

Question 26

What drug is the most common cause of Steven Johnson syndrome?

Answer 26

Sulfonamides

Question 27

What drug can cause kernicterus in neonates by displacing bilirubin from albumin?

Answer 27

Sulfonamides, due to high albumin binding.

Question 28

Sulfonamides SE?

Answer 28

Hypersensitivity (SJS) Hemolysis in G6PD deficiency Photosensitivity Kernicterus in neonates

Question 29

What is a side effect unique of Trimethoprim or pyrimethamine?

Answer 29

They are sulfonamides and can cause bone marrow suppression.

Question 30

What is the MOA of flouroquinolones?

Answer 30

Quinolones are bactericidal and interfere with DNA synthesis. Inhibit toposisomerase II (DNA gyrase) and topoisomerase IV (responsible for separation of replicated DNA during cell division)

Question 31

What are quinolones indicated for?

Answer 31

UTIs STIs/ PIDs Diarrhea to : shigella, salmonella, E. coli, Campylobacter.

Question 32

What drug causes inhibition of chondrogenesis?

Answer 32

Flouroquinolones, which are contraindicated in pregnancy and in children. Other SE include: Tendonitis, tendon rupture Phototoxicity CNS effect (Insomnia, dizqziness, headache)

Question 33

What is the regimen for H.Pylori?

Answer 33

Amoxicillin or Metronidazole Omeprazole Omeprazole Clarithromycin Clarithromycin

Question 34

What is the MOA of Metronidazole and what organisms are they indicated for?

Answer 34

Metronidazole are indicated for anaerobes, it is converted to free dradicals by ferredoxin, binds to DNA and other macromalecules, bactericidal.

Question 35

What drug decreases visual acuity and red-green discrimination?

Answer 35

Ethambutol

Question 36

What drug produces these combination of SE? Hepatitis, Induction of P450, Red-orange metabolites.

Answer 36

Rifampin, inhibits DNA-dependent RNA polymerase. All body fluids are orange with this drug.

Question 37

What is the MOA of "Azoles" antifungals?

Answer 37

It inhibits 14-alpha-demethylase prevents lanosterol conversion to ergosterol.

Question 38

What is the only Azole antifungal that crosses BBB and treat meningeal infections?

Answer 38

Flucanazole, it penetrates CSF, as it is lipid soluble.

Question 39

What drug inhibits Squalene epoxidase?

Answer 39

Terbinafine, preventing conversion of squalene to squalene epoxide. Number one drug for treatment of tinea infections.

Question 40

What lab abnormality will we see in a sub-set of pts taking TMP-SMX?

Answer 40

Leukopenia.

Question 41

What are the NRTIs?

Answer 41

Zidovudine (AZT): SE: hematotoxicity, peripheral neuropathy. Didanosine: SE: Pancreatitis, peripheral neuropathy Lamivudine: used in Hepatitis B. No SE

Question 42

What is the monophosphate nucleotide anolog (NtrTI)?

Answer 42

Tenofovir.

Question 43

What are the fusion inhibitor drugs used for HIV?

Answer 43

Enfuvirtide: binds to gp41 and inhibits the fusion HIV-1 to CD-4+ cells. Maraviroc: blocks the binding of the gp-120 HIV protein to CCR5 on macrophage surface to prevent viral entry.

Question 44

What is the MOA of Zanamivir and Oseltamivir?

Answer 44

Inhibit neuraminidases of influenza A and B (enzymes that prevent clumping of virions, so that more particles are available for infecting host cells).

Question 45

What is the DOC for treating Amebiasis , Giardiasis, and Trichomoniaisis?

Answer 45

Metronidazole

Question 46

What is the prophylaxis for Plasmodial infections (malaria)?

Answer 46

Chloroquine.

Question 47

P. Vivax and P. Ovale need to be treated with two drugs? Why?

Answer 47

Chloroquine gives us a clinical cure, gets rid of the fever, but once the drug is discontinued the liver form of plasmodium infects us against, hence these pts need to be treated with Primaquine as well.

Question 48

SE of antimalarials in G6PD deficiency pts.?

Answer 48

Hemolysis. Caused byPimaquine and Quinine / Quinidine (Cinchonism). A non-antilmalarial drug that can also cause this is sulfonamides

Question 49

What is the MOA of Oseltamivir / Zanamivir?

Answer 49

Inhibit influenza nuraminidase, decreases release of progeny virus.

Question 50

Thymidine kinase is a viral enzyme that adds phosphate groups to guanosine anologs, thereby activating the metabollite form of the drug. Which drug is this? what does it inhibit?

Answer 50

Acyclovir, famciclovir, and valacyclovir. Triphosphate formed by cellular enzymes, preferentially inhibits viral DNA pol by chain termination. For HSV / VZV Ganciclovir has similar MOA but targets CMV

Question 51

What's the MOA of NRTIs and what can we give HIV pts to counteract toxicity?

Answer 51

It competitive inhibits nucleotide binding to reverse transcriptase and terminates DNA chain. It causes BM supression which can be reversed with granulocyte colony-stimulating factor (G-CSF) and Erythropoietin) All need to be phosphorylated to be active