Antiparasitics

Question 1

What combination of drugs can prevent Toxoplasmosis?

Answer 1

Sulfamethoxazole/Trimethaprim

Question 2

What can we assume about the metabolism of Toxoplasmosis

Answer 2

It is a manufacturer of Folic Acid

Question 3

What is the most common tx for Trichomoniasis?

Answer 3

Metronidazole

Question 4

What percentage of patients have metronidazole resistant Trich?

Answer 4

5%

Question 5

Drugs used for Malaria?

Answer 5

–  Chloroquine
–  Quinine
–  Primaquine
–  Quinidine
– Artimisinins (Artesunate, Artemether)

Question 6

What catagory of drug is Chloroquine?

Answer 6

Antiprotozoal

Question 7

MOA of Chloroquine?

Answer 7

Damages parasitic DNA. Damages the membrane of a RBC that is infected by the parasite.
Also inactivates an enzyme of Plasmodium that normally polymerizes the heme that is released as the parasite digests the host hemoglobin. Soluble heme is toxic to the parasite.

Question 8

Distinguishing characteristics of Chloroquine?

Answer 8

– Related to Quinine, Quinidine, Primaquine
– PO. Rapidly absorbed. Early treatment of disease may allow for cure in less than one week. Resistance is now reported in some parts of the world.

Question 9

Predicted actions of Chloroquine?

Answer 9

Prophylaxis or acute treatment of malaria due to P. falciparum.

Question 10

Adverse/Side effects of Chloroquine?

Answer 10

GI upset, headaches, pruritus.
Can cause retinal damage.

Use cautiously in patients with hepatic dysfunction. Can cause severe
hemolysis in patients with G6PD deficiency.

Question 11

What is the Achilles Heel of the infectious mycotic organisms that are susceptible to azoles?

Answer 11

Ergosterol (the mycotic version of cholesterol, that we don’t have)

Question 12

How do azoles work?

Answer 12

They prevent the formation of ergosterol

Question 13

What drugs prevent the activity of ergosterol?

Answer 13

Amphotericin B

Question 14

Patients who are taking Metronidazole cannot simultaneously use _______.

Why?

Answer 14

Alcohol

Pathway for breakdown path of ethyl alcohol.
Alcohol dehydrogenase, converts ETOH to acetylaldehyde. No place for it to go - can’t become acetate and it builds up: vascular HA, difficulties in vision, all sx of nasty hangover.
(SO SENSITIVE - aftershave has caused it. Penetrating skin or inhaled ETOH)

Question 15

MOA of Metronidazole?

Answer 15

Binds to protozoan or anaerobic bacterial DNA halting cell division.

Question 16

Distinguishing characteristics of Metronidazole (4)?

Answer 16

– Azole compound
– Inhibits aldehyde dehyrodgenase in liver – Highly lipid soluble
– Metallic taste

Question 17

Predicted actions of Metronidazole?

Answer 17

– Absorbed via all routes.
– Distributed all tissue.
– Yeast and tinea overgrowth

Question 18

CI of Metronidazole

Answer 18

– Use cautiously in patients with hepatic dysfunction. Can cause severe hemolysis in patients with G6PD deficiency.
– Contraindicated with ethanol

Question 19

What category of drug is Mebendazole?

Answer 19

Anthelminthic (Most commonly used of all the antihelminthics)

Question 20

MOA of Mebendazole?

Answer 20

Microtubule destruction

Question 21

Distinguishing characteristics of Mebendazole?

Answer 21

– Available in the form of a chewable tablet – Has few adverse effects
– Excreted unchanged in the feces
– Avoid use during pregnancy

Question 22

Predicted actions of Mebendazole?

Answer 22

Effective against pinworms, roundworms, whipworms, and hookworms

Question 23

What category of drug is Ivermectin?

Answer 23

Antiparasitic

Question 24

MOA of Ivermectin?

Answer 24

Intensified release of GABA transmission

Question 25

Predicted actions of Ivermectin?

Answer 25

– Cidal to helminths and arthropods

– Systemic distribution to parasites

Question 26

CI of Ivermectin?

Answer 26

– Avoid with benzodiazepines and barbiturates

– Avoid during pregnancy