Antoprotozoals And Antihelmintic Agents

Question 1

What is the etiology of amebiasis?

Answer 1

Entamoeba histolytica

Question 2

What are the two forms of E. Histolytica and which one is the infective one?

Answer 2

Cysts = infective

Trophozoites

Question 3

What are the two phases of E histolytica, and which one is symptomatic?

Answer 3

Liver phase=symptomatic

Lumen phase =asymptomatic

Question 4

If one person in the household has e. Histolytica, do you need to treat the rest of the household?

Answer 4

Yes, it is spread via food, water, and contact, and is a “population” disease. Usually the whole household is infected

Question 5

What is the etiology of giardiasis?

Answer 5

Giardia lamblia

Question 6

How is trichomoniasis spread?

Answer 6

Sexually

Question 7

If one person has trichomoniasis, does their partner?

Answer 7

Yes you need to treat both partners. Men are usually asymptomatic though.

Question 8

What is the characteristic symptom of trichomoniasis in women?

Answer 8

Vaginitis

Frothy yellow discharge 🤮

Question 9

Is toxoplasmosis a big deal for healthy people?

Answer 9

No, it is a mild infection in people with good immune systems

Question 10

Is toxoplasmosis a big deal for pregnant women and immunocompromised peopel
/

Answer 10

Yes, can cause major problems to the fetus and can be life threatening to someone with an incompetent immune system

Question 11

What is the etiology of pneumocystis aka PCP?

Answer 11

Pneumocystis jirovecii

Pneumocystis carinii

Question 12

For what population is pneumocystosis a big deal?

Answer 12

AIDS patients

MAJOR cause of death for them via pneumocystis pneumonia

Question 13

What drugs are the tissue amebicides for entamoeba histolytica?

Answer 13

Metronidazole

Tinidazole

Emetine + Dehydroemetine

Question 14

What are the luminal amebicides used for asymptomatic luminal phases of entamoeba histolytica?

Answer 14

Iodoquinol

Paromomycin

Tetracycline and erythromycin

Question 15

What is the drug of choice for entamoeba histolytica?

Answer 15

Metronidazole (with or without a luminal amebicide)

You would give just the luminal amebicide if they were asymptomatic- no metronidazole

Question 16

What is the DOC for giardia?

Answer 16

Metronidazole

Question 17

What is the DOC for trichomonas vaginalis?

Answer 17

Metronidazole

Question 18

What are the DOCs for toxoplasma gondii (toxoplasmosis)?

Answer 18

Pyrimethamine-sulfadiazine + leucovorin

Question 19

What are the DOCs for pneumocystis jirovecii/carinii?

Answer 19

Bactrim + leucovorin

Question 20

How many treatments of metronidazole do we give for giardiasis or trichomoniasis?

Answer 20

Single treatment

Question 21

How does metronidazole get activated?

Answer 21

It gets reduced by ferredoxin, which is only in anaerobes

Question 22

What is the MOA of metronidazole?

Answer 22

Its metabolites are taken up into DNA where they form unstable molecules

Question 23

Will metronidazole kill amoebas in luminal phase?

Answer 23

No, must combine with luminal agent

Question 24

What are the side effects of metronidazole?

Answer 24

Metallic taste

Disulfiram-like reaction

Nervous system toxicity with prolonged use, but we don’t use metronidazole for long periods

GI upset, superinfection

Question 25

What is the main point about tinidazole?

Answer 25

It’s a metronidazole alternative

Question 26

When would we use emetine + dehydroemetine (Mebadin)?

Answer 26

Severe amebiasis infections in which metronidazole didn’t work (Last resort, very toxic)

Question 27

What are the side effects of emetine+dehydroemetine (mebadin)?

Answer 27

Cardiotoxicity**** Serious GI upset Teratogenicity****

Question 28

If someone is pregnant and metronidaozle didn’t work for their amebiasis infection, can we give them an injection of emetine+dehydroemetine(Mebadin)?

Answer 28

NO VERY TERATOGENIC

Question 29

Who can NOT have emetine+dehydroemetine (Mebadin)

Answer 29

Heart disease Kidney disease Pregnant women *****

Question 30

What is the main use of iodoquinol?

Answer 30

Luminal phase of e. histolytica aka asymptomatic amebiasis

Question 31

What are the toxicities of iodoquinol?

Answer 31

Iodine-induced thyroid enlargement Eye problems, possible blindness

Question 32

What do we use paromomycin for?

Answer 32

Asymptomatic amebiasis Giardiasis Trichomonas vaginalis

Question 33

What are the side effects of paromomycin?

Answer 33

GI upset! | Even though it is an aminoglycoside, you don’t get ototoxicity/nephrotoxicity since it is not significantly absorbed

Question 34

What kind of medication is paromomycin?

Answer 34

Aminoglycoside

Question 35

What are tetracycline and erythromycin used for?

Answer 35

Alternative treatments for amebiasis and giardiasis after paromomycin didn’t work either

Question 36

What other drug will be given with tetracycline/erythromycin for symptomatic amebiasis patients?

Answer 36

Metronidazole

Question 37

What is the drug of choice for toxoplasmosis?

Answer 37

Pyrimethamine + sulfadiazine

Question 38

What kind of infection is toxoplasmosis (toxoplasma gondii)?

Answer 38

Opportunisitic infection

Question 39

Is pyrimethamine + sulfadiazine static or cidal?

Answer 39

It is static, So, it can be given prophylactically for toxoplasmosis, as well as can be given for active infection, but will not clear the infection.

Question 40

What should you give with pyrimethamine+sulfadiazine?

Answer 40

Leucovorin**

Question 41

What is the drug of choice for pneumocystis pneumonia (caused by P. jirovecii/P. carinii)?

Answer 41

Bactrim | Don’t forget it is a sulfa

Question 42

30% of AIDS patients can not tolerate Bactrim :( | And since pneumocystis pneumonia is one of the biggest killers of AIDS patients, what are they supposed to take?

Answer 42

Pentamidine

Question 43

What is pentamidine usually reserved for?

Answer 43

Patients who can’t tolerate bactrim | Not as effective and more toxic though

Question 44

What microbe causes pneumocystis pneumonia (PCP)?

Answer 44

Pneumocystis jirovecii Or pneumocystis carinii (It is a yeast like fungus)

Question 45

What is the mechanism of action of bactrim? I forgot

Answer 45

Inhibition of folate metabolism | Synergy between trimethoprim and sulfamethoxazole

Question 46

What are the main toxicities of bactrim? I forgot

Answer 46

Hypersensitivity Stevens Johnson syndrome Photosensitivity Aplastic anemia for G6PD

Question 47

When you treat someone with an antihelminthic drug, what usually causes the side effects?

Answer 47

The worms dying. Not the drug It’s usually just some flu-like symptoms

Question 48

What are the DOCs for roundworms (nematodes)?

Answer 48

Albendazole Mebendazole Pyrantel pamoate

Question 49

What is the MOA of albendozole and mebendazole?

Answer 49

Binds to B-tubulin and inhibitis the microtubule-dependent uptake of glucose (Starves the worms)

Question 50

What is an alternative treatment for roundworms(nematodes)?

Answer 50

Ivermectin DOCs were albendazole, mebendazole, or pyrantel pamoate

Question 51

What are the adverse effects of albendazole and mebendazole?

Answer 51

Kills fetuses Do not use in pregnant women

Question 52

What is the MOA of pyrantel pamoate?

Answer 52

Its a cholinesterase inhibitor that produces a depolarize game neuromuscular blockade

Question 53

What is the MOA of ivermectin?

Answer 53

Paralyzes the worm by intensifying GABA-mediated transmission of signals in peripheral nerves

Question 54

What is the DOC for flukes and tapeworms?

Answer 54

Praziquantel

Question 55

What is an alternative treatment for flukes?

Answer 55

Bithionol | DOC is praziquantel

Question 56

What is an alternative treatment for tapeworms?

Answer 56

Niclosamide | DOC is praziquantel

Question 57

What is the MOA of praziquantel?

Answer 57

Increasing worm’s permeability to Ca++, resulting in contraction and paralysis of the worms muscles (Dislodges the worm)

Question 58

What is the MOA of bithionol?

Answer 58

Uncoupled oxidative phosphorylation= no ATP synthesis

Question 59

Paromomycin is an aminoglycoside, so will we see the same ototoxicity and nephrotoxicity we see with other aminoglycosides?

Answer 59

No, because it is not well absorbed from GI tract