Antiprotazoals

Question 1

characteristics and classifications of protozoa

Answer 1

• classified based on adult stage motility
• unicellular

Question 2

target transmission of protozoa

Answer 2

vectors
(insects and person to person)

Question 3

considerations of anti-protozoal drugs

Answer 3

not safe during pregnancy
toxic at therapeutic doses
drug resistance

Question 4

what anaerobic protozoa (amebiasis) causes disease

Answer 4

entamoeba histolytica

Question 5

transmission of amebiasis

Answer 5

oral-fecal route

Question 6

what does an amebic cyst do

Answer 6

survives GA contents, pass into lumen, transformes into trophozoites in large intestinal lumen and feed off of enteric bacteria

Question 7

symptoms of amebiasis

Answer 7

• asymptomatic - intestinal lumen
• severe diarrhea, abdominal cramps
• colitis and bloody diarrhea
• amebic dysentery

Question 8

when does a patient get amebic
- severe diarrhea and cramps
- dysentery
- liver abscess

Answer 8

• trophozoites invade intestinal epithelium
• ulcerate colonic mucosa in large intestine
• infect portal vein and travel to liver

Question 9

treatment of asymptomatic amebic intestinal lumen infection

Answer 9

paromomycin or iodoquinol (only dual therapy)

Question 10

what type of antibiotic and amebicide is paromomycin

Answer 10

aminoglycoside
luminal amebicide

Question 11

what type drug is iodoquinol (diiodihydroxyquinoline)

Answer 11

halogenated hydroxyquinoline
luminal amebicide

Question 12

contraindications of iodoquinol

Answer 12

used in addition to other drugs used to treat other forms of amebiasis

Question 13

what is used to treat moderate infection and invasive colitis (intestinal, extraintestinal, & tissue infection)

Answer 13

nitroimidazoles

Question 14

clinical pearl of nitroimidazoles

Answer 14

avoid with alcohol

Question 15

what does metronidazole treat

Answer 15

extraluminal amebiasis, amebic colitis, and dysentery

Question 16

where is metronidazole less effective

Answer 16

eliminating cysts in bowel lumen

Question 17

MOA of metronidazole

Answer 17

PFOR reduces ferredoxin which activates metronidazole through reduction which creates a short-lived nitro-free radical which binds to DNA protein and INHIBITS DNA synthesis and induces its degredation

Question 18

metronidazole also kills

Answer 18

anaerobes

Question 19

MOA of tinidazole

Answer 19

generation of cytotoxic free radicals and drug interactions

Question 20

what can tinidazole treat

Answer 20

intestinal amebiasis and liver abscess

(not asymptomatic cyst/luminal)

Question 21

what can nitazoxanide treat

Answer 21

metronidazole resistant protozoal strains

Question 22

proposed MOA of nitazoxanide

Answer 22

noncompetitive inhibitor of pyruvate PFOR enzymes

Question 23

symptoms of cryptosporidiosis

Answer 23

asymptomatic
watery diarrhea
stomach cramps
N/V
fever
weight loss
* life threatening in immune compromised individuals

Question 24

treatment of cryptosporidiosis

Answer 24

nitazoxanide

Question 25

most commonly diagnosed intestinal parasite in the US that is transmitted as a cyst in feces contaminated water, soil, food, or water

Answer 25

giardiasis

Question 26

which giardia form is most drug resistant

Answer 26

cyst

Question 27

symptoms of giardia and its treatments

Answer 27

asymptomatic to D, gas, abdominal cramps, greasy floating stools, dehydration malnutrition in kids due to failure to absorb fat, lactose, vitamin A and B12 #1 - metronidazole nitazoxanide tinidazole

Question 28

cause of common forms of vaginitis and urethritis that is an STD

Answer 28

trichomoniasis

Question 29

symptoms of trichomoniasis

Answer 29

itching or irritation discomfort during urination discharge

Question 30

treatment of trichomoniasis

Answer 30

#1 metronidazole nitazoxanide tinidazole

Question 31

a sporozoa, obligate intracellular parasite

Answer 31

toxoplasma gondii

Question 32

transmission of toxoplasma gondii

Answer 32

foodborne-undercooked, contaminated meat and veggies human to animal (cats) transplacental fetal infection

Question 33

symptoms of toxoplasmosis

Answer 33

asymptomatic if immunocompromised: reactivation of tissue cysts in brain causing encephalitis (fever, confusion, HA, seizures, poor coordination) mild flu like sx stillbirth, miscarriage, child with toxoplasmosis - large/small head, vision loss, mental disability, seizures

Question 34

toxoplasmosis treatment

Answer 34

3 drug combo - pyrimethamine (folate analog competitive inhibition) - sulfadiazine (antifolate inhibiting protozoal dihydropteroate synthase and PABA) - leucovorin calcium (reduced folate)

Question 35

why do you give leucovorin calcium

Answer 35

to offset hematologic complications due to pyrimethamine induced folic acid deficiency

Question 36

what causes African sleeping sickness

Answer 36

trypanosoma brucei gambiense or T. b. rhodesiense

Question 37

what is trypanosomiasis transmitted by

Answer 37

tsetsefly

Question 38

early stage hemolymphatic trypanosomiasis

Answer 38

parasites live and grow in blood & lymph. Itching, fever, jpint pains, chills, HA, lymphadopathy

Question 39

late stage meningoencephalitis trypanosomiasis

Answer 39

invade CNS (severe HA) inflammation of brain and spinal cord producing lethargy mental deterioration continuous sleep coma death if untreated

Question 40

treatment for early stage trypanosomiasis

Answer 40

pentamidine isethionate suramin

Question 41

moa of pentamidine

Answer 41

binds DNA in kinetopast with high affinity, inhibits kinetopast replication and function inhibits RNA, phospholipid, protein synthesis

Question 42

treats early and late stage t. b. (with CNS involvement)

Answer 42

eflornithine

Question 43

which type of T.b does eflornithine treat

Answer 43

ONLY t. b gambiense with nifurtimox

Question 44

adverse effects of suramin

Answer 44

neurological complications

Question 45

adverse effects of eflornithine

Answer 45

seizures in overdose death

Question 46

only option and 1st line therapy for treating T. b. rhodesiense (2nd line for T b gambiense

Answer 46

melarsoprol

Question 47

MOA melarsoprol

Answer 47

inhibits pyruvate kinase --> inh. glycolysis --> inh atp synthesis inhibits adenine and adenosine uptake by trypanosomal transporters

Question 48

adverse effects of melarsoprol

Answer 48

4-6% death rate fever, vomiting, abdominal pain immediately phlebitis reactive encephalopathy - brain inflammation polyneuropathy renal disease cardiac disease

Question 49

how to lessen adverse effects of melarsoprol - brain inflammation: - polyneuropathy: -GI side effects:

Answer 49

corticosteroids thiamine fasting prior to administration

Question 50

Chaga's disease (american trypanosomiasis) cause and transmission

Answer 50

trypanosoma cruzi transmitted via reduviid insect vectors

Question 51

acute chaga's disease symptoms

Answer 51

granuloma "chagoma" unilateral orbital edema fever, hepatosplenomegaly and lymphadenopathy

Question 52

chronic chaga's disease symptoms

Answer 52

cardiomyopathy and HF 1st degree heartblock - right bundle branch block arrhythmias enlargement of esophagus and color (mega syndrome) meningoencephalitis strokes seizures focal paralysis

Question 53

1st line treatment of chaga's disease

Answer 53

benznidazole

Question 54

moa benznidazole

Answer 54

inhibits protein and RNA synthesis

Question 55

2nd line and investigational treatment of chaga's disease

Answer 55

nifurtimox

Question 56

moa nifurtimox

Answer 56

generates intracellular oxygen radicals inhibits parasite enzyme trypanothione reductase

Question 57

what is special about nifurtimox

Answer 57

activity against motile parasites

Question 58

monitoring for both benznidazole and nifurtimox

Answer 58

blood count, hepatic, CMP