Anti-Virals & Antibiotics

Question 1

Acyclovir MOA

Answer 1

Competitively inhibits viral DNA polymerase; competes w/ deoxyguanosine triphosphate for incorporation into viral DNA

Question 2

Acyclovir Tox

Answer 2

Neurotoxicity including seizures; Hydrate pt well to avoid crystalline nephropathy or neurotox

Question 3

Acyclovir PK

Answer 3

Little metabolism; renal elim; dose adj in renal dysfxn or failure may occur

Question 4

Interesting fact about acyclovir and oral dose levels

Answer 4

*Oral bioavailability DECREASES with INCREASING dose; Req TK activity

Question 5

Famciclovir MOA

Answer 5

Competitively inhibits viral DNA polymerase; competes w/ deoxyguanosine triphosphate for incorporation into viral DNA

Question 6

Famciclovir Tox

Answer 6

No significant issues; Hydrate pt

Question 7

Famciclovir PK

Answer 7

Little metabolism; renal elim; dose adj in renal dysfxn or failure may occur

Question 8

Benzathine Pen G MOA

Answer 8

Bactericidal Beta-Lactam: binds PBPs causing cell lysis

Question 9

Benzathine Pen G Tox

Answer 9

Poor penetration of CSF (not good tx for neurosyphilis); HSR or skin rxns may be problematic; Jarisch-Herxheimer Rxn (do NOT D/C penicillin)

Question 10

Benzathine Pen G PK

Answer 10

Rapidly eliminated via renal tubular excretion (delayed in renal dysfxn)

Question 11

Benzathine Pen G Admin

Answer 11

IM admin produces a drug depot that liberates drug over 2 week period

Question 12

Use of procaine Pen G

Answer 12

Congenital Syphilis

Question 13

Azithromycin MOA

Answer 13

Binds 50S ribosomal subunit; Bacteriostatic

Question 14

Azithromycin Tox

Answer 14

GI upset, vaginitis

Question 15

Azithromycin PK

Answer 15

Little metabolism; most elim in stool; long half-life; extensive tissue uptake & slow release

Question 16

Doxycycline MOA

Answer 16

Binds 30S ribosomal subunit; Bacteriostatic

Question 17

Doxycycline Tox

Answer 17

GI upset; hepatic damage in high dose esp in pregnancy; photosensitivity w/ sunlight or tanning bed

Question 18

Doxycycline PK

Answer 18

Little metabolism; most elim in stool; long half-life; extensive tissue uptake & slow release

Question 19

Doxycycline Pregnancy Cat

Answer 19

D

Question 20

Levofloxacin/Ofloxacin MOA

Answer 20

Inhibits DNA gyrase (topo II) in Gram-negative; Inhibits topo IV in Gram-positive; Bactericidal (both)

Question 21

Levofloxacin/Ofloxacin Tox

Answer 21

Taste disturbance; GI upset; 2 BBW

Question 22

Levofloxacin/Ofloxacin BBW

Answer 22

BBW=increased risk of tendonitis & rupture; BBW=exacerbation of muscle weakness-avoid in Myasthenia Gravis

Question 23

Levofloxacin/Ofloxacin PK

Answer 23

Little metabolism; most elim in urine; medium half-life (prolonged in renal dysfxn)

Question 24

Fluoroquinolones pregnancy cat

Answer 24

Cat C

Question 25

Ceftriaxone MOA

Answer 25

Bactericidal Beta-Lactam: binds PBPs causing cell lysis

Question 26

Ceftriaxone PK

Answer 26

Medium half-life; widely distributed; elim in urine primarily via GF

Question 27

Metronidazole MOA

Answer 27

Unionized drug taken up by anaerobic organisms & cells where it is reduced to its active form which disrupts DNA's helical structure; Amebecidal, bactericidal, & trichomonacidal

Question 28

Metronidazole Tox

Answer 28

GI upset; candidiasis; disulfram-like effect (avoid alcohol for 24 hours after completing therapy); secondary malignancies maybe

Question 29

Metronidazole PK

Answer 29

Medium half-life; widely distributed; extensive hepatic metabolism w/ elim primarily in urine & stool; Inhibits CYP2C9

Question 30

Metronidazole in pregnancy

Answer 30

Avoid in pregnancy & breastfeeding

Question 31

Metronidazole interesting fact

Answer 31

*Discoloration of urine upon elimination

Question 32

Clindamycin MOA

Answer 32

Binds 50S ribosomal subunit to inhibit protein synthesis; Bacteriostatic

Question 33

Clindamycin Tox

Answer 33

Systemic- GI upset; Local Vag- vaginal erythema, vulvovaginal pruritis, vaginal discharge, vaginal swelling, vaginal bleeding, vaginal pain

Question 34

Clindamycin PK

Answer 34

Short half-life; extensive metabolism w/ elim of products in urine & stool; 30% of vaginally instilled drug becomes systematized

Question 35

Clindamycin in breast feeding

Answer 35

Excreted in breast milk- no issues but caution

Question 36

Clindamycin in pregnancy

Answer 36

Intravag use only in 1st trimester due to AE of low birth wt, pre-term, PPROM, & neonatal infxns

Question 37

Butoconazole MOA

Answer 37

Blocks ergosterol synthesis through interacting w/ 14-alpha-demethylase, a CYP necessary for conversion of lanosterol to ergosterol

Question 38

Butoconazole Tox

Answer 38

Oil-based products can weaken latex condoms or diaphragms

Question 39

Butoconazole PK

Answer 39

Limited systemic absorption; peak serum levels in 12-24 hrs; residual fungicidal activity in vagina for several days; systemic drug ext metabolized & recovered in stool

Question 40

Butoconazole in pregnancy

Answer 40

Avoid in 1st trimester; High systemic doses produce abdominal wall defects & cleft palate in fetus + maternal stress

Question 41

Cervarix MOA

Answer 41

Bivalent: 16 + 18 - L1 protein

Question 42

Cervarix Tox

Answer 42

Injection site irritation & pain may occur

Question 43

Gardasil MOA

Answer 43

Quadrivalent: 6, 11, 16, 18 - L1 protein

Question 44

Gardasil Tox

Answer 44

Injection site irritation & pain may occur