Antiparasitic Drugs

Question 1

What is a broad spectrum drug against Round Worms?

Answer 1

Mebendazole - low systemic

Question 2

What is a common mechanism between Mebendazole and Albendazole?

Answer 2

They both disrupt microtubules and immobilize the parasite.

Question 3

What drug is typically used for systemic round worm infections and Echinococcus?

Answer 3

Albendazole - metabolite is active and distributes throughout body.

Question 4

What drug is used for strongyloides and hook worms larvae?

Answer 4

Thiabendazole

Question 5

What drug is used as an alternative for broad spectrum round worm infections?

Answer 5

Thiabendazole

Question 6

What round worm drug is most rapidly absorbed and which has the least absorption?

Answer 6

Rapidly Absorbed - Thiabendazole

Poorly Absorbed - Mebendazole and Pyrantel Pamoate

Question 7

What drug is primarily used to treat pin worms and hook worms?

Answer 7

Pyrantel Pamoate

Question 8

How does Pyrantel Pamoate work on the round worms?

Answer 8

depolarizing neuromuscular blocker causing paralysis of the worms.

Question 9

What is the drug of choice for schistosoma fluke infections?

Answer 9

Praziquantel - some activity against other trematodes

Question 10

What drug is used as a broad spectrum against cestodes (tapeworms)?

Answer 10

Praziquantel

Question 11

What is the best treatment for taenia solium (pork tape worm from undercooked meat)?

Answer 11

Praziquantel - additionally kills the eggs and larvae together stopping the infection

Question 12

What drug is used to treat neurocysticerosis (once the larvae migrate into the brain)?

Answer 12

Albendazole (Remember - drug metabolite is well distributed throughout body)

Question 13

What drug is used if the patient is a wussie and can’t tolerate other medications for cestrodes?

Answer 13

Paromomycin Sulfate

Question 14

How do antimalarial drugs typically work?

Answer 14

They do not kill the sporozoites, but prevent the spread within the body and the immune system kills them.
–Prevents progression of symptoms–

Question 15

When an individual is in the endemic zone of malaria what is the target of the preventative drug?

Answer 15

RBC from of the disease of all species

Question 16

After leaving the endemic zone, what should the targets of the therapy be?

Answer 16

Hepatocyte Form - for 14 days after leaving endemic zone of P. Vivax and Ovale.

Question 17

In regards to disease process, how are P. Malariae and Falciparum similar?

Answer 17

They only have hepatic form at the beginning of the infection the stay in the RBC form.

Question 18

How do you have to treat P. Vivax and P. Ovale differently compared to the other forms of malaria?

Answer 18

They can have latent hepatic infection that can reside lifelong, so treatment must target both RBC and Hepatic forms.

Question 19

How does Chloroquine selectively target infected RBCs?

Answer 19

The drug is a weak base that can diffuse, but in the an infected RBC there is an acidic vacoule that charges the drug now allowing it to escape, essentially concentrating in the infection.

Question 20

What drug would you take while you are in Africa to prevent malaria?

Answer 20

Chloroquine

Question 21

What is the mechanism of Chloroquine?

Answer 21

Prevents heme polymerase, causing a build up of free radicals effectively killing the parasite.
(Resistance is increasing year by year)

Question 22

What two forms of malaria can Chloroquine treat?

Answer 22

P. Falciparum
P. Malariae
–Unable to kill the hepatic infections of the other two–

Question 23

What is a side effect of prolonged use of Chloroquine?

Answer 23

Visual impairment

Question 24

What drug can be used to treat/prevent malaria if it is resistant to Chloroquine?

Answer 24

Mefloquine

Question 25

What are the side effects of Mefloquine and who should not take it?

Answer 25

Causes CNS effects - anxiety, depression, paranoia, vertigo, etc. Individuals with psychiatric disorders or siezures should not take it can make symptoms worse. (Even if taking psychiatric drugs)

Question 26

What is the two drug combination that treats/prevents RBC malaria and works synergistically?

Answer 26

Atovaquone + Proguanil - -more specifically can treat Chloroquine resistant P. Falciparum - Better tolerated, but more expensive

Question 27

How does each drug of Atovaquone and Proguanil work?

Answer 27

Atovaquone - inhibits mitocondrial transport preventing pyrimidine synthesis Proguanil - inhibits dihydrofolate reductase, blocking pyrimidine synthesis

Question 28

What drug can be used for fast action in acute malaria infections?

Answer 28

Quinine - similar mechanism of Chloroquine

Question 29

What drug can be used as a second line for chloroquine resistant P. Falciparum?

Answer 29

Quinine.

Question 30

What are common side effects of Quinine?

Answer 30

Cinchonism - causes all the following symptoms. | Headache, visual distrubances, dizziness, and tinnitis.

Question 31

What drug can be used for broad spectrum bacteria coverage and can treat malaria?

Answer 31

Doxycyline

Question 32

What are the three ways Doxycyline can treat malaria?

Answer 32

- decreases protein synthesis - depresses dihydroorate dehydrogenase synthesis - inhibits prymidine synthesis

Question 33

When is it most common to use Doxycycline for malaria?

Answer 33

Multi-drug resistant P. Falciparum or prevent of Chloroquine-resistant strains.

Question 34

What anti-malarial drug can be used to treat hepatocyte latent infection of P. Vivax and P. Ovale?

Answer 34

Primaquine

Question 35

What drug would you give a patient who had returned from an endemic zone for 14 days?

Answer 35

Primaquine - to kill of any P. Vivax and Ovale that remained or were able to penetrate to the liver.

Question 36

Who should not take Primaquine due to adverse reaction and hemalytic anemia?

Answer 36

Individuals with G6PDH deficiencies.

Question 37

What drugs would you use for an asymptomatic entamoeba histolytica?

Answer 37

Iodoquinol or Paromomycin Sulfate - targets the lumen of the bowel, does not penetrate tissues

Question 38

What drug would be used for symptomatic infection that can penetrate the tissues of the bowel?

Answer 38

Metronidazole | Should also used Iodoquinol or Paromomycin

Question 39

What are unique effects of Paromomycin Sulfate and Iodoquinol?

Answer 39

Iodoquinol - should not be used for people with iodine allergies Paromomycin Sulfate - does not absorb, minimal systemic side effects, tolerated well

Question 40

What drug can be used for both Trichomonas and Giardia Lamblia?

Answer 40

Metronidazole

Question 41

What drug is commonly used for Giardia Lamblia and Cryptosporidum?

Answer 41

Nitazoxanide (not first choice for Giardia)

Question 42

What drug is used to treat Toxoplasma and treat/prevent pneumocystitis jiroveci?

Answer 42

Atovaquone

Question 43

What are common treatment options for pneumocystisis jiroveci?

Answer 43

1. TMP/SMX 2. Clindamycin + Primaquine 3. Atovaquone 4. Dapsone