STDs

Question 1

MOA of benzathine Penicillin G

Answer 1

bactericidal beta-lactam binds PBPs causing cell lysis.

Poor CSF penetration

Question 2

ADE of benzathine penicillin G

Answer 2

rapid renal elimination (avoid renal failure)
hypersensitivity and skin rashes.

Jarisch-Herxheimer Reaction with most secondary syphilis patients after first injection: chills fever headache myalgias and arthralgia. Lesions become brilliant in color. Do NOT discontinue penicillin. Aspirin gives relief.

Question 3

MOA of procaine Pen G?

Answer 3

penicillin mixed with procaine, a local anisthetic. Goal is to reduce pain of large IM injections.

Question 4

MOA of acyclovir

Answer 4

guanosine analog. Inhibits viral DNA polymerase and competes with deoxyguanosine triphosphate for incorporation into viral DNA.
REQUIRES thymidine kinase phosphorylation.

Question 5

ADE of acyclovir

Answer 5

neurotoxicity including seizures because it penetrates CSF

Patient must be well hydrated to avoid crystalline nephropathy

Question 6

MOA of cidofovir

Answer 6

viral DNA polymerase inhibitor. DOES NOT REQUIRE PHOSPHORYLATION BY thymidine kinase.

Question 7

ADE of cidofovir

Answer 7

nephrotoxicity.
Give probenecid (urocosuric) to prevent it.

Question 8

MOA of famciclovir

Answer 8

Guanosine analog. Famciclovir is metabolized to penciclovir and does not cause chain termination. Inhibits viral DNA polymerase by competing with deoxyguanosine triphosphate.

Requires thymidine kinase phosphorylation.

Question 9

ADE of famciclovir

Answer 9

no significant issues. FAMcyclovir=Family friendly

Patient must be well hydrated to avoid crystalline nephropathy

Question 10

MOA of cervarix

Answer 10

recombinant L1 protein (major antigenic protein of HPV capsid).
Protects against HPV 16 and 18 (bivalent)

Question 11

ADE of cervarix

Answer 11

injection site irritation and pain

Question 12

MOA of gardasil

Answer 12

recombinant L1 protein (major antigenic protein of HPV capsid).
Protects against HPV 6, 11, 16 and 18 (quadrivalent)

Question 13

ADE of gardasil

Answer 13

injection site irritation and pain

Question 14

MOA of azithromycin

Answer 14

macrolide. binds 50S ribosomal subunit: bacteriostatic

Question 15

ADE of azithromycin

Answer 15

GI upset

vaginitis

Question 16

MOA of ceftriaxone

Answer 16

cephalosporin. beta-lactam; binds PBPs causing cell lysis. bactericidal

Question 17

MOA of clindamycin

Answer 17

binds 50S ribosomal subunit to inhibit protein synthesis. bacteriostatic.

Question 18

ADE of clindamycin

Answer 18

When used intravaginally, increases risk of low birthweight and pre-term delivery.
Excreted in breast milk.
GI upset even when given intravaginally.
vaginal pain

Question 19

MOA of doxycycline

Answer 19

tetracycline. binds 30S ribosomal subunit: inhibits protein synthesis. bacteriostatic

Question 20

ADE of doxycycline

Answer 20

GI upset
hepatic damage in high dose (esp in pregnancy)
photosensitivity
Cat. D teratogen

Question 21

MOA of levofloxacin

Answer 21

fluoroquinolone. Inhibits DNA gyrase (topo II) in gram negative: bactericidal
Inhibits topo IV in gram-positive

Question 22

ADE of levofloxacin

Answer 22

taste disturbance (levo -> leavened bread taste)
BBW of risk of tendonitis and rupture
BBW of exacerbation of muscle weakness
Contraindicated with myasthenia gravis
Cat. C teratogen

Question 23

MOA of metronidazole

Answer 23

metro–>multi.
amebicidal, bactericidal and trichomonacidal.
Taken up by anaerobic organisms and cells where it is reduced to active form and disrupts DNA helical structures, inhibiting bcterial nucleic acid synthesis.
Equally effective against dividing and non-dividing cells.

Question 24

ADE of metronidazole

Answer 24

extensive hepatic metabolism.
Urine discoloration.
Disulfiram-like effect (avoid alcohol)
Inhbiits CYP2C9
Avoid in pregnancy and breastfeeding.

Question 25

MOA of ofloxacin

Answer 25

fluoroquinolone. Inhibits DNA gyrase (topo II) in gram negative: bactericidal
Inhibits topo IV in gram-positive

Question 26

ADE of ofloxacin

Answer 26

BBW of risk of tendonitis and rupture
BBW of exacerbation of muscle weakness
Contraindicated with myasthenia gravis
Cat. C teratogen

Question 27

ADE of butaconazole

Answer 27

high doses produce abdominal wall defects and cleft palate in fetus. avoid in 1st trimester.

Can weaken latex condoms because oil based.

Question 28

MOA of butaconazole

Answer 28

blocks ergosterol synthesis from lanosterol.

interacts with 14-alpha demethylase (CYP) necessary for conversion of lanosterol

Question 29

What is the Jarisch-Herxheimer Reaction?

Answer 29

occurs in most secondary syphilis patients after first injection of penicillin: chills fever headache myalgias and arthralgia. Lesions become brilliant in color. Do NOT discontinue penicillin. Aspirin gives relief.