Clindamycin, Colistin, Fosfomycin, Macrobid, Fluoroquinolones, macrolides

Question 1

Clindamycin (Cleocin) MOA

Answer 1

binds 50S ribosome to inhbitis RNA-dependent protein synthesis, bactericidal for GPCs

Question 2

Spectrum of clindamycin

Answer 2

gram positive, aerobes, CA-MRSA, MSSA, drug resistant S. pneu, anaerobes, bacteroides, prevotella, clostridium perfringens, p. jiroveci, toxoplasmosis gondii

Question 3

What are negatives of clindamycin?

Answer 3

may induce C. Dif, carries risk of inducible resistance during single course therapy

Question 4

ADRs of clindamycin (Cleocin)

Answer 4

Gi intolerance, C. diff

Question 5

Normal dose of clindamycin

Answer 5

PO- 150-300 mg QID, IV- 600-900 mg Q6h

Question 6

Clinical uses of clindamycin

Answer 6

CA- MRSA SSTI, B. fragilis, anaerobes, acne, encephalitis due to toxoplasma gondii, PCP pneumonia in AIDS pt w/ bactrim allergy, bacterial vaginosis, ASP pneu, “above diaphragm”

Question 7

Colistin MOA

Answer 7

cationic detergent that binds to and damages bacterial membrane, causes leakage of intracellular contents, rapidly bactericidal, conc dependent

Question 8

Specctrum of activity of colistin

Answer 8

GNR, enterobacteriaceae, pseudomonas, all MDR GNR, carbapenem resistant pathogens

Question 9

Colistin PK

Answer 9

IV only, sometimes nebulizer, renally eliminated

Question 10

ADRs of colistin

Answer 10

nephrotoxicity, common but reversible, neurotoxic- paresthesias, slurred speech, confusion, coma, and seizures

Question 11

Use of colistin

Answer 11

only when have to!

Question 12

Fosfomycin (Monurol) MOA

Answer 12

inhibits bacterial cell wall synthesis by inactivating an enzyme critical in development of the cell wall, bactericidal

Question 13

Spectrum of activity of fosfomycin (Monurol)

Answer 13

e. coli, enterococcus, k. pneu, proteus, S. aureus

Question 14

Fosfomycin PK

Answer 14

PO only, concentrates well in urine and maintains adequate [urine]

Question 15

ADRs of fosfomycin

Answer 15

well tolerated, HA, N/V/D

Question 16

Dose of fosfomycin

Answer 16

3 gm PO x 1, for UTIs x1, for complicated- q 2-3 days, x2-3 dose

Question 17

Clinical use of fosfomycin

Answer 17

because of activity against MDR pathogenscan easily solve a therapeutic dilemma, UTI, limited use in non-UTI infxns

Question 18

nitrofurantoin (Macrobid) MOA

Answer 18

inhibit protein synthesis via several mechanisms, little bacterial resistance, bactericidal

Question 19

Spectrum of activity of nitrofurantoin (macrobid)

Answer 19

e. coli, enterococcus, s. aureus, klebsiella, enterobacter, resistance increasing

Question 20

Nitrofurantoin PK

Answer 20

PO only, preg cat B, functioning kidneys, contraindicated with CrCl

Question 21

Clinical use of nitrofurantoin

Answer 21

UTI, UTI prophylaxis, acute cystitis

Question 22

Fluoroquinolone options

Answer 22

Ciprofloxacin, levofloxacin (Levaquin), Moxifloxacin (Factiv), gemifloxacin, ofloxacin

Question 23

MOA of fluoroquinolones

Answer 23

inhibit replication of bacterial DNA by inhibiting DNA gyrase, gram +: readily pass through cell membrane and enter cytoplasm to reach target site; gram -: diffusion through outer wall and cytoplasmic membrane via porins

Question 24

Fluoroquinolones PK

Answer 24

well absorbed IV/PO, bactericidal, concentration dependent, all except moxi are renally eliminated

Question 25

Spectrum of fluoroquinolones

Answer 25

good gram - coverage, enterobacteriaceae, pseudomonas, h. influenzae, neisseria, m. catarrhalis, aerobic gram +, MSSA (not cipro), s. pneu (not cipro), mycobacteria, atypicals- very active

Question 26

What should fluoroquinolones not be used for?

Answer 26

CA- MRSA, or anaerobes

Question 27

DI of fluoroquinolones

Answer 27

antiacids (administer 4 hrs apart), warfarin (reduce by 50%), food- take on empty stomach

Question 28

Fluoroquinolones ADRs

Answer 28

N/V/D (induce C. diff), rash, avoid in children, QTc prolongation, achilles tendon rupture

Question 29

Clinical use of fluoroquinolones

Answer 29

UTI (not moxi), U/LRTI, pneumonia, COPD, sinusitis, CF, abd infxns, skin, osteo, great s. pneu and atypical coverage

Question 30

Macrolides options

Answer 30

azithromycin (Zithromax), erythromycin, clarithromycin (Biaxin), fidaxomicin (Dificid)

Question 31

Azithromycin (Zithromax) dose

Answer 31

Z-pak: 500 mg PO daily x1 then 250 mg daily x4, 500 mg IV daily

Question 32

Macrolids MOA

Answer 32

bind to 50 S ribosome to inhibit RNA- dependent protein synthesis, time dependent, slowly bactericidal or bacteriostatic

Question 33

Spectrum macrolides

Answer 33

streptococci, H. influenzae, M. Catarrhalis (bactericidal), staph- clarithromycin best, atypicals and mycobacteria, bordetella, syphillis and chlamydia

Question 34

Macrolides PK

Answer 34

less absorbed/ effective at acidic pH, very large Vd, azithromycin t1/2= 66 hrs

Question 35

ADRs of macrolides

Answer 35

GI, taste disturbances- clarithromycin, QTc prolongation

Question 36

Macrolide DI

Answer 36

lots with erythromycin and clarithromycin, not as many w/ azithromycin

Question 37

Clinical use of macrolides

Answer 37

U?LRTI- azithro, atypical- azithro, H. pylori- clarithromycin, chlamydia

Question 38

Fidaxomicin (Dificid) MOA

Answer 38

a macrolide, PO only

Question 39

Fidaxomicin (Dificid) spectrum of activity

Answer 39

C. diff

Question 40

Fidaxomicin (Dificid) ADRs

Answer 40

well tolerated, GI, GI bleed

Question 41

Fidaxomicin (Dificid) pearls

Answer 41

$$$$$, more efficacious than vancomycin