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Flashcards in ANTIMICROBIALS Deck (230):
1

The AE of which drug can be largely prevented by administration of histamines and a slow infusion rate?

Vancomycin (red man syndrome)

1

Which tetracycline is rarely used as an antibiotic but instead to act as a diuretic in SIADH?

Demeclocycline

1

What is the mechanism of resistance to tetracyclines?

Decreased uptake by cells or increased efflux by PLASMID ENCODED GENES

1

What autoantibodies may be found in the serum of a person on isoniazid?

Antihistone; it causes a lupus like syndrome

1

Which enzyme activates isoniazid to the active form?

Mycobacterial Catalase Peroxidase (KatG)

1

Which antifungal binds ergosterol but is only available topically? Which is used systemically?

Nystatin; Ergosterol

2

What is the mechanism of resistance to acyclovir?

mutation of viral thymidine kinase

3

The uptake of which type of antibiotics is inhibited by divalent cations?

Tetracyclines

3

Which drugs inhibit 50 S and prevent translocation?

Macrolides

4

Which type of antibiotics is aztreonam synergistic with?

aminoglycosides

5

What is nifurtimox used to Tx?

Trypanosoma cruzi

6

Which aminopenicillin has the greatest oral bioavailability?

amOxicillin (greater Oral) than ampicillin

6

Which carbapenem does not require coadministration of cilastatin? What does this mean?

Meropenem, it is not degraded in kidneys by dehydropeptidase I

6

MOA of oseltamivir

neuraminidase inhibitor that decreases release of influenza A and B viral progeny

7

What 2 types of HSV infections can you use acyclovir for? What is the benefit of valacyclovir?

mucocutaneous (i.e. genitals and cold sores) and encephalitis; better oral bioavailability

8

What do you use to treat NADPH oxidase deficiency?

IFN gamma

9

MOA of trimethoprim

Inhibits dihydrofolate reductase

10

How do you prevent postsurgical infection due to S. aureus?

Cefazolin

10

What can be treated with IFN alpha? (3)

HBV, HCV, and Kaposi

11

What cephalosporin is used prior to surgery to prevent S. aureus skin infections?

cefazolin

12

Why do you avoid chloramphenicol in pregnancy?

Gray Baby syndrome, baby has low levels of UDP glucuronyl transferase

12

MOA of foscarnet

Pyrophosphate analog that inhibits CMV viral DNA polymerase

13

Which drugs inhibit fungal cell wall synthesis by inhibiting B-glucan?

Caspofungin and Anidulfungin

13

What is the mechanism of resistance to ganciclovir?

mutated CMV DNA polymerase or viral kinase

13

In which circumstance could you use foscarnet in a ganciclovir resistant strain of CMV?

If the resistance is from lack of viral kinase. Foscarnet does not require viral kinase, however, if the resistance is from viral DNA pol then neither will work

14

What highly virulent bug is covered by ceftaroline?

MRSA

14

This antibiotic blocks peptidyltransferase at the 50S subunit

Chloramphenicol

15

What is pyrimethamine used to treat?

Toxoplasmosis

15

What is sodium stibogluconate used to Tx?

Leishmaniasis

17

What is the mechanism of resistance to penicillins?

Beta Lactamase

17

Why do you avoid fluoroquinolones in pregnancy?

Cartilage damage

18

Why do you avoid ribavirin in pregnancy?

Teratogenic

19

Which TB drug may cause optic neuropathy?

Ethambutol

19

MOA of zanamavir

neuraminidase inhibitor that decreases release of influenza A and B viral progeny

20

Which drugs are given as prophylaxis for A) Mycobacterium tuberculosis B) MAC and C) M. leprae?

A) Isoniazid B) Azithromycin (when CD4

20

What is Terbinafine? Terbutaline?

Terbinafine is an antifungal that inhibits squalene epoxidase and is used to Tx dermatophytes; Terbutaline is a B2 agonist used to relax the uterus

21

Which generation of cephalosporins covers gram positive bacteria and Proteus, E. coli, Klebsiella, Haemophilus, Enterobacter, and Neisseria?

Second Generation (HEN PEcK)

22

What inhibits the uptake of tetracyclines?

Divalent cations: milk, antacids, or iron

22

What is triple therapy for H pylori?

Metronidazole, Clarithromycin and PPI's

22

Which 2 antifungals affect cell wall synthesis?

Caspofungin and Anidulfungin

22

Which antiviral inhibits IMP dehydrogenase?

Ribavirin

22

How can you reverse the bone marrow suppression caused by NRTI's?

G-CSF and EPO

22

What kind of drugs are nevirapine, delavirdine, and efavirenz?

NNRTI's

23

How do you prophylax against gonorrhea?

Ceftriaxone

24

What 7 bugs are covered by aminopenicillins that are not by penicillins?

Haemophilus influenzae b, E. coli, Listeria, Proteus, Salmonella, Shigella, and Enterococci (HELPSS kill enterococci)

24

How do you treat tuberculous leprosy?

Dapsone and Rifampin

25

What are 3 AE of ampicillin?

Hypersensitivity, Ampicillin rash if underlying mono, and pseudomembranous colitis

25

How do you prophylax against meningitis?

Ciprofloxacin = adults; Rifampin = kids

25

What is the MOA of raltegravir?

inhibits HIV integrase

26

What makes nafcillin, oxacillin, and dicloxacillin resistant to beta lactamases?

They have a bulky R group which sterically hinders them

27

MOA of metronidazole?

disulfiram like reaction, headache, and metallic taste

28

This TB drug blocks arabinosyltransferase and decreases carbohydrate polymerization of the cell wall

Ethambutol

28

Major AE of rifampin

orange body fluids and hepatoxicity (induce CYP450)

29

Which drug is used against cryptococcus and is converted to 5-FU by cytosine deaminase?

Flucytosine

30

What are the AE of penicillins (2)?

Hypersensitivity reactions and Hemolytic anemia

30

Aminoglycosides and tetracyclines both act on _____ S

30 S

30

What drug is used to treat Giardia in A) Non pregnant and B) Pregnant

A) metronidazole B) Paramomycin

31

Which antibiotic inhibits dihydrofolate reductase? Which drug also does this as an antineoplastic?

Trimethoprim; Methotrexate

33

Which antifungals inhibit nucleic acid synthesis?

5-Flucytosine

34

This tetracycline is excreted fecally rather than renally

Doxycycline

34

What is the antiviral that inhibits IMP dehydrogenase indicated for (2)?

This is ribavirin (Chronic Hepatitis C and RSV)

35

What molecule is truly a "quinolone"?

nalidixic acid --all others are FLUOROquinolones

36

Which 30S inhibitors are bacteriostatic and bactericidal?

Bactericidal = aminoglycoside; Bacteriostatic = tetracyclines

38

Which electrolytes need to be supplemented when on amphotericin B?

K and Mg

40

What is the difference between acyclovir and ganciclovir?

Not much really, both are guanosine analogs that are monophosphorylated by a viral kinase HOWEVER, ganciclovir is more effective against CMV and acyclovir is more effective against HSV

40

Name the 3 NNRTI's

Nevirapine, Efavirenz, and Delavirdine

41

Which cephalosporin covers MRSA?

Ceftaroline

43

What other disorders can hydroxychloroquine be used for aside from malaria?

Rheumatologic disorders

43

What is special about tenofovir when compared to other NRTI's?

Does not have to be activated

44

What may relieve the bone marrow issues of trimethoprim?

Leucovorin = same as rescue for methotrexate (folinic acid)

44

MOA of nystatin

Binds ergosterol to form membrane pores in fungi; unlike amphotericin B, only available topically because too toxic

45

How do you prophylax against syphilis?

Benzathine penicillin G

46

What determines the half life of isoniazid?

whether the person is a fast or slow acetylator

48

Which generation of cephalosporins covers gram positive bacteria and Proteus, E. coli, and Klebsiella?

First Generation (PEcK)

49

What is the MOA of aztreonam?

Monobactam that prevents peptidoglycan crosslinking by binding to PBP3

49

What must you co-administer with cidofovir?

It is nephrotoxic so it should be given probenicid and IV saline to decrease toxicity

50

What bugs are covered by first generation cephalosporins?

Gram positives and Proteus, E. coli, and Klebsiella (PeCK)

51

Which 3rd generation cephalosporin is used against Pseudomonas?

Ceftazidime

53

How do you prophylax against strep pharyngitis in a kid with Hx of rheumatic fever?

oral penicillin

54

What is the MOA of griseofulvin?

Interferes with fungal microtubules and disrupts mitosis

56

How do you prophylax against gonococcal and chlamydial conjunctivitis in a newborn?

Erythromycin ointment

56

What are the 2 most serious side effects of amphotericin

Nephrotoxicity and Arryhthmias (and the arrhythmias are ultimately due to the nephrotoxicity)

57

What is the mechanism of resistance to macrolides

methylation of the 23S rRNA binding site

58

Which type of bugs can vancomycin be used against?

GRAM POSITIVE ONLY

59

This TB drug blocks the synthesis of mycolic acid

Isoniazid

59

This TB drug blocks DNA dependent RNA polymerase

Rifampin

60

What drug inhibits HIV integrase

Raltegravir

61

Which antifungal drug interferes with microtubule function and may be carcinogenic?

Griseofulvin

62

MOA of ergosterol

Binds ergosterol to form membrane pores in fungi

64

Describe the full MOA of acyclovir

Gets into cells and is monophosporylated by viral thymidine kinase to the active form. This then functions as a guanosine analog and causes CHAIN TERMINATION (no 3' OH)

65

Which type of beta-lactam have seizures as an AE?

Carbapenems

66

What bugs are covered by second generation cephalosporins?

Gram positives, Haemophilus, Enterobacter, Neisseria, Proteus, E. coli, Klebsiella (HEN PEcK)

68

What are the AE (6) of sulfonamides?

Hypersensitivity, hemolysis in G6PD, nephrotoxicity (tubulointerstitial nephritis), photosensitivity, KERNICTERUS, and displace drugs from albumin such as warfarin

69

How do you prevent red man syndrome?

Antihistamines and a slow infusion rate of vancomycin

70

What is the MOA of cilastatin, always given with?

Inhibits renal dehydropeptidase I to prevent the breakdown of imipenem

72

Which beta-lactams may cause vitamin K deficiency? How would this manifest?

Cephalosporins, bleeding (loss of II, VII, IX, X, and proteins C and S)

73

This TB drug has an unknown MOA but may acidify the intracellular environment by forming _____________

Pyrazinamide; pyrazinoic aci

74

Which bactericidal antibiotics inhibit formation of the initiation complex and cause misreading of mRNA?

aminoglycosides

75

Ototoxicity with aminoglycosides is potentiated with __________ while nephrotoxicity is potentiated with ______________

Loop diuretics; Cephalosporins

75

Which type of anemia is formed by trimethoprim? What could you give to rescue?

Megaloblastic anemia (lack of folate); rescue with folinic acid (leucovorin) same as for methotrexate

76

Which antibiotics function by blocking DNA topoisomerase II and IV?

Fluoroquinolones

77

Which ribosomal inhibitor has a dose dependent risk of aplastic anemia?

chloramphenicol

79

What is the MOA of aminoglycosides

Bind 30 S ribosome to inhibit formation of initiation complex

81

What is the MOA of ribavirin?

inhibits synthesis of guanine nucleotides by inhibiting IMP dehydrogenase

82

Which drug that treats anaerobes blocks peptide transfer at 50S?

clindamycin

82

What is used to Tx flukes such as Schistosomes?

Praziquantel

83

Which drugs all end in -navir?

Protease inhibitors

85

Which 2 antifungals inhibit lanosterol synthesis?

Naftifine and Terbinafine

87

Which protease inhibitor can cause hematuria?

Indinavir

88

Which bacteria are not affected by aztreonam?

Gram positive and Anaerobes (Dr. Randolf: Aztreonam is the atom bomb of gram negatives)

89

Which antibiotic is best for anaerobes above the diaphragm?

Clindamycin

90

Which antibiotic is best for anaerobes below the diaphragm?

Metronidazole

92

With which drugs are aminoglycosides synergistic? What problems arise?

Cephalosporins potentiate them but they also increase the risk for nephrotoxicity

93

What is the major AE of chloroquine?

Retinopathy

94

Methylation of the 23S rRNA binding site confers resistance to __________

Macrolides but not telithromycin (a ketolide)

94

Which drug is indicated to treat Hep C and RSV?

Ribavirin

95

DOC for Trypanosoma brucei

Suramin and melarsoprol

96

What is the MOA of caspofungin and micafungin

inhibit cell wall synthesis by inhibiting synthesis of B-glucan

96

What CMV drug must be coadministered with probenecid?

Cidofovir due to nephrotoxicity

97

Which drugs are indicated for both influenza A and B?

Neuraminidase inhibitors = oseltamavir and zanamavir

98

What is the mechanism of resistance to the aminopenicillins?

Beta-lactamases (same as regular penicillins)

99

Why is cefazolin used prior to surgery?

To prevent staphylococcal wound infections

101

Which gene encodes HIV-1 protease?

pol gene

102

Which azole is best for chronic suppression of cryptococcal meningitis?

Fluconazole

104

Why do you avoid tetracyclines in pregnancy?

Discolored teeth and inhibition of bone growth

106

How do you prophylax against group B strep in a carrier pregnant female?

Ampicillin (intrapartum)

108

Which types of bugs can carbapenems be used against?

Gram positive, Gram negative, and anaerobe = very wide spectrum but serious AE = seizures

110

What are the AE of ganciclovir?

BONE MARROW AND KIDNEY (renal toxicity, leuko, neutro, thrombocytopenia)

111

What is praziquantel used to Tx?

Flukes such as Schistosoma

113

Which 2 types of antibiotics cannot be taken with antacids?

Tetracyclines and Fluoroquinolones

114

Which medication would increase the likelihood of tendon rupture in a patient taking fluoroquinolones?

Corticosteroids (prednisone)

115

What is the DOC for Leishmaniasis?

Sodium Stibogluconate

116

AE of macrolides (5)

Motility issues, Arrhythmia (QT prolonged), Cholestatic hepatitis, Rash, eOsinophilia (MACRO)

117

Why do you avoid sulfonamides in pregnancy?

Potential for kernicterus

118

Name 2 antipseudomonals

Ticarcillin and Piperacillin

120

What 5 types of drugs block protein synthesis at the 50 S ribosomal subunit?

Chloramphenicol, Macrolides, Clindamycin, Streptogramins, and Linezolid

121

What are the penicillinase resistant penicillins?

Nafcillin, Oxacillin, and Dicloxacillin

123

What are the main 3 AE of protease inhibitors?

Hyperglycemia, GI intolerance, and Lipodystrophy

125

Which aminoglycoside is commonly used for bowel surgery?

Neomycin

126

What kind of bugs are covered by 3rd generation cephalosporins?

Serious gram negative infections

127

What kind of drugs are ampicillin and amoxicillin?

AMINOpenicillins

128

Which azole is best for candidal infections of all kinds?

Fluconazole

129

What is the mechanism of resistance to aminoglycosides?

transferase enzymes that inactivate the drug via acetylation, adenylation, or phosphorylation

130

What drug is impenem always adminstered with and why?

Cilastatin to decrease renal dehydropeptidase I? This would inactivate imipenem

131

Which monobactam prevents peptidoglycan crosslinking by binding to PBP3

Aztreonam

133

What are the AE of cephalosporins?

Hypersensitivity, Vitamin K deficiency (bleeding), and increased nephrotoxicity of aminoglycosides

134

What do you use to treat onychomycosis?

Terbinafine

136

What are the 4 AE of vancomycin?

Nephrotoxicity, Ototoxicity, and Thrombophlebitis as well as Red Man Syndrome

136

Which CMV drug is a pyrophosphate analog?

Foscarnet

137

What 2 bugs can TMP-SMX prophylax against in an AIDS patient? Azithromycin?

TMP-SMX = Pneumocystis when CD4

138

What are ticarcillin and piperacillin used for?

Antipseudomonal penicillins

139

Name 2 aminopenicillins

Ampicillin and Amoxicillin

140

What is the MOA of ethambutol? AE?

Blocks arabinosyltransferase which decreases carbohydrate polymerization of the cell wall; optic neuropathy

142

How can bacteria become resistant to fluoroquinolones?

mutation in DNA gyrase, plasmid mediated resistance, efflux pumps

143

What is the common toxicity of all CMV drugs?

Nephrotoxicity

144

Which antiviral should you use against HSV? VZV?

HSV = Acyclovir; VZV = Famciclovir

144

What is IFN B used to TX?

Multiple Sclerosis

145

Which form of malaria is resistant to chloroquine?

P. falciparum--Tx with artemether/lumifantrine or atovaquone/proguanil

146

What is the AE of flucytosine?

Bone Marrow Suppression

147

What kind of bugs are covered by 4th generation cephalosporins?

Pseudomonas and gram positives

149

Which drugs block the conversion of lanosterol to ergosterol?

azoles

151

Compare the AE of penicillins to the penicillinase-resistant penicillins

Regular penicillins = hypersensitivity and hemolytic anemia whereas Penicillinase resistant ones are allergic rxns and interstitial nephritis

152

Name 3 CMV drugs

Ganciclovir, Foscarnet, and Cidofovir

154

What is the AE of zidovudine?

anemia (NRTI)

155

Which azole is most likely to cause gynecomastia?

Ketoconazole by inhibiting testosterone synthesis

156

Which drugs block mRNA synthesis?

Rifampin

158

Why do you avoid clarithromycin in pregnancy?

Embryotoxic

160

What drug is often co-administered with ticarcillin and piperacillin? Why?

Clavulanic acid, inhibits beta lactamase

161

How do you treat life-threatening malaria?

Quinidine (quinine in places outside US)

162

Which drug, related to ganciclovir, is a prodrug with better bioavailability?

Valganciclovir

164

What is the mechanism of resistance to chloramphenicol?

Plasmid-encoded acetyltransferase that inactivates it

165

Which bacteria is penicillin most effective for?

Gram positives but also some gram negatives and spirochetes (Syphilis)

166

Why do you avoid griseofulvin in pregnancy?

Teratogenic

168

What is the advantage of a cephalosporin over a penicillin regarding beta-lactamase?

Cephalosporins are overall less sensitive to beta lactamase

168

What is the general rule for clindamycin and metronidazole?

Clindamycin = anaerobes above the diaphragm; Metronidazole = anaerobes below the diaphragm

169

What is the AE of terbinafine? What is it used to treat?

abnormal LFTs; used to treat onychomycosis

170

Why do you avoid aminoglycosides in pregnancy?

They are ototoxic

171

What is famciclovir used for?

VZV; this drug is related to acylclovir

173

Which drug is used to Tx the hypnozoites of Plasmodium vivax malaria?

Primaquine

175

This drug inhibits renal dehydropeptidase I to prevent breakdown of imipenem

cilastatin

177

Which 2 antifungals affect membrane function?

Amphotericin B, Nystatin

178

What is used to treat VRE?

Streptogramins (quinupristin and dalfopristin)

179

Which antifungals inhibit ergosterol SYNTHESIS?

the conazoles

180

What kind of bacteria are aminoglycosides most effective against?

gram negative

181

What are the 2 neuraminidase inhibitors?

Zanamavir and Oseltamivir

183

What is the MOA of the azoles for antifungal therapy? How is it different from terbenafine?

Inhibition of the CYP450 that converts lanosterol to ergosterol; Terbenafine inhibits squalene epoxidase which converts squalene to lanosterol

184

2 antibiotic classes inhibiting 30 S

Aminoglycosides and tetracyclines

185

Which protease inhibitor is used to "boost" others by inhibiting cytochrome P450?

Ritonavir

187

How do you treat lepromatous leprosy?

Dapson, Rifampin, and Clofazimine

189

What are 3 beta-lactamase inhibitors?

Clavulanic acid, sulbactam, and tazobactam

190

What is valganciclovir?

Prodrug of ganciclovir with better oral bioavailability

191

What are 3 mechanisms of resistance to sulfa drugs?

Increased PABA production to outcompete, alteration of dihydropteroate synthase, or decreased uptake

192

In which generation of cephalosporins do you lose gram positive coverage?

3rd (ceftriaxone, cefotaxime, and ceftazidime)

193

What drug can be used to treat HBV, HCV, and Kaposi's?

IFN alpha

194

What are suramin and melarsoprol used to treat?

Trypanosoma brucei

194

What is the MOA of chloroquine?

Blocks detoxification of heme to HEMOZOIN so heme accumulates and is toxic to plasmodia

195

Which tetracycline is best for a renally impaired patient?

Doxycycline because it is fecally excreted

196

How do you prophylax against endocarditis from surgery and dental procedures?

Penicillins

197

What are the AE of the penicillinase-resistant penicillins?

Hypersensitivity reactions and Interstitial nephritis

199

Why are tetracyclines so effective against Chlamydia and Rickettsia?

They can accumulate intracellularly

200

What is the AE of raltegravir?

hypercholesterolemia

201

Is it safe to give cephalosporins in a penicillin allergic patient?

yes there is low cross-reactivity between the two

202

Which ribosomal inhibitors can cause QT prolongation?

macrolides

203

DOC for 1) T. brucei 2) T. cruzi

1) Suramin and Melarsoprol 2) Nifurtimox

204

What are the 3 anti-staphylococcal penicillins?

Nafcillin, Oxacillin, and Dicloxacillin

205

Which bacteria can you NOT use the penicillinase resistant penicillins on?

MRSA

206

What is the MOA of flucytosine? Used for?

blocks DNA and RNA synthesis by using cytosine deaminase to convert to 5 FU

207

How do you prevent neurotoxicity in a patient on isoniazid?

Pyridoxine (B6)

208

Which azole is best for Blastomyces, Coccidiodes, and Histoplasma?

Itraconazle

210

Which antifungal deposits in keratin-containing tissues?

Griseofulvin

211

What is the DOC for toxoplasmosis? Prophylaxis in AIDS?

Pyrimethamine; TMP-SMX when CD4 less than 100

212

What are the AE of ribavirin (2)?

Hemolytic anemia and SEVERE TERATOGEN

213

What is the most important AE of carbapenems?

Seizures! Use is therefore limited to serious drug rxns

214

DOC for Trypanosoma cruzi

Nifurtimox

215

What is the MOA of macrolides?

Bind to 23S rRNA at the 50S ribosome and prevent translocation

216

What are sulbactam, tazobactam, and clavulanic acid used for?

Beta lactamase inhibitors

217

How are NNRTI's different from NRTI's?

They bind to reverse transcriptase at a different site than the NRTI's

218

In which setting would you choose aztreonam over aminoglycosides? Can you give both?

In renal failure because aminoglycosides are nephrotoxic. However, the two are synergistic so can be given together under other circumstances.

219

What is the MOA of sulfa drugs?

They are PABA antimetabolites that inhibit dihydropteroate synthase

220

Which drugs inhibit squalene epoxidase and therefore prevent formation of lanosterol?

Terbinafine and Naftifine

221

In which tissue is griseofulvin most likely to deposit?

Keratin containing tissues

222

How do you prophylax against recurrent UTI's?

TMP-SMX

223

What are the 4 AE of aminoglycosides?

Nephrotoxicity, Neuromuscular blockade, Ototoxicity, and Teratogenic

224

What is the MOA of tetracyclines?

Inhibit 30 S to prevent attachment of aminoacyl tRNA

225

Why do infants on chloramphenicol get "Gray baby syndrome"

They lack liver UDP-glucuronyl transferase to glucuronidate it

226

Which NRTI does NOT have to be activated?

Tenofovir

227

Which drugs potentiate the nephrotoxicity of aminoglycosides?

Cephalosporins

228

Which ribosomal inhibitors can cause cholestatic hepatitis?

Macrolides

229

How can you reduce the nephrotoxicity of amphotericin B?

HYDRATE

230

What is the utility of ritonavir vs. other protease inhibitors?

Ritonavir is used to boost the concentrations of others by inhibiting cytochrome P450