Week 3 Other Antimicrobials

Question 1

Acyclovir Indications and MOA

Answer 1

1. Herpes Simplex Virus (HSV) 1 and 2
2. Varicella-Zoster
3. EBV and CMV

Phosphorylated 3 times but requires virus specific thymidine kinase so only targets viruses. Final form inhibits viral DNA synthesis

Question 2

Acyclovir Metabolism and Excretion

Answer 2

Excreted by the kidneys; Renal dosing is required

Question 3

Acyclovir Precautions and ADRs

Answer 3

1. Thrombotic thrombocytopenicpurpura/hemolytic uremic syndrome (TTP/HUS)
2. Nephrotoxicity and ATN
3. Neurologic Effects

Question 4

Famciclovir MOA

Answer 4

Metabolized to acyclovir analogue. Achieves higher and longer intracellular concentration

Question 5

Valacyclovir MOA

Answer 5

Prodrug of acyclovir with good oral bioavailability. All other attributes are the same as acyclovir

Question 6

Nirmatrelvir with Ritonavir (Paxlovid) MOA

Answer 6

Nirmatrelvir inhibits COVID replication
Ritonavir inhibits CYP3A4 metabolism to increase nirmatrelvir concentration

Question 7

Paxlovid Excretion and Metabolism

Answer 7

Urine and Feces

Question 8

Paxlovid ADR and Contraindications

Answer 8

1. Avoid administration of CYP3A drugs due to inhibition
2. Dysgeusia has been reported
3. Renal dose adjust with CrCl<60

Question 9

CYP3A metabolized drugs

Answer 9

1. Amiodarone
2. Statins
3. Sildenafil
4. Opioids

Question 10

Remdesivir MOA

Answer 10

Metabolized into active metabolite that inhibits RNA synthesis

Question 11

Remdesivir Metabolism and Excretion

Answer 11

Urine

Question 12

Remdesivir ADR

Answer 12

Nausea and LFT abnormalities

Question 13

Oseltamivir and Zanamivir MOA and Indication

Answer 13

1. Neuraminidase inhibitors that prevent release of virus to stop propagation
2. Influenza A and B

Question 14

Antifungal Medications 5 answers

Answer 14

1. Fluconazole
2. Itraconazole
3. Ketoconazole
4. Terbinafine
5. Voriconazole

Question 15

Terbinafine MOA

Answer 15

Inhibits squalene epoxide; An early step in ergosterol formation
Fungalstatic at low concentration; higher concentrations are more bacterialcidal

Question 16

Azole MOA

Answer 16

Inhibits fungal cell wall formation by inhibiting the fungal CYP450 enzyme stopping ergosterol formation

Question 17

Difference between Fluconazole and other azoles

Answer 17

Has been shown to have less human CYP450 inhibition

Question 18

Azole Boxed Warning and Monitoring
Including terbinafine

Answer 18

Liver failure and hepatitis
Monitor LFTs before and during treatment

Question 19

Albendazole and Mebendazole MOA

Answer 19

Bind to beta-tubulin of the microtubule of parasitic worms causing loss of function

Question 20

Ivermectin MOA

Answer 20

Causes parasitic paralysis and death

Question 21

Pyrantel Pamoate MOA

Answer 21

Depolarizing NMBA creating spastic paralysis in the worm

Question 22

Albendazole and Mebendazole Metabolism

Answer 22

Liver

Question 23

Metronidazole MOA

Answer 23

Deactivates DNA and other proteins in bacteria

Question 24

Metronidazole Precautions

Answer 24

1. Blood Dyscrasias
2. Hepatic Dysfunction
3. Do not take with alcohol because of disulfiram like reactions