Gi: Parasites

Front 1

Is Entamoeba Histolytica :
protozoa
flatworm
roundworm

Describe it's life cycle.

What takes place in asympt chronic cases? Can this individual spread the infection?

Are cysts able to form in those with active diarrhea?

Back 1

protozoa

cyst ingestion --> trophozoites form in sm. intes. where they:
a)mult in bowel lumen
b)encyst and ulcerate in the intes. wall
c)portal vein --> liver --> abscesses & hepatitis

cysts form in intestine and are passed in the feces
- no

No, they are not.

Front 2

What is the drug of choice for tx'ing all invasive forms of amebic infection?
- mech?
- SE?
- contraindications?

Back 2

metronidazole
- inhibits anaerobic metabolism of parasite
- nausea, HA, drymouth; unpleasant sensations if used w/ alcohol.
- pregnancy

Front 3

What type of organisms are giardia and trichomonas? Tx?

Back 3

protozoan parasites; one intestinal, the other genital

Metronidazole

Front 4

What is the difference b/t plasmodium vivax and plasmodium falciparum re: # of exoerythrocytic cycles in the liver?

Implications for tx?

Back 4

vivax can go thru several cycles

falciparum - only once

Tx for vivax must be active in both exoerythrocytic and erythrocytic cycles
...whereas falciparum tx need only be active erythrocytically

Front 5

Chloroquine
- exo or erythrocytically active?
- gametocidal against which?
- mech?
- degraded by which organ?
- can it build up over long tx?
- short term SE?
- long term?

Back 5

- erythrocytic only
- vivax, ovale, malariae (not falciparum)
- inhibits parasite breakdown of host hemoglobin.
- liver
- yes
- GI upset, HA, blurring of vision
- retinal damage, palsies b/c drug b/ to mucles.

Front 6

Primaquine
- exo or erythrocytically actv?
- actv against which organisms?
- actv against which gametocytes?
- cleared quickly or slowly?
- SE?
- who is sensitive? Why?

Back 6

- exoerythrocytic cycle
- exo forms of vivax and ovale.
- all 4 parasites
- quickly
- can cause leukocytosis, ^^doses --> BM suppression
**can cause hemolysis in those with Primaquine sensitivity.
- esp. AA males; G6PD deficiency

Front 7

Some Chloroquine-resistance is being seen in falciparum. What is the current 1st line in falciparum tx?

Back 7

Malarone
or
Quinine + doxycycline
or
Mefloquine

Front 8

What is Malarone?
- mechs?
- SEs?
- uses?

Back 8

Atovaquone + Proquanil
1. interferes w/ mitochondrial e transport i/ parasite
2. DHFR inhibitor
- HA, GI upset
- tx of chloroquine resistant falciparum

Front 9

Mefloquine
- class?
- uses in malarial tx?
- SEs?

Back 9

- quinolone
- chloroquine resistant falciparum
- CNS related:
+dizziness
+headache
+vivid dreams
+rare psychotic events

Front 10

T. Brucei can cause complications in which system that especially worrisome?

T. Cruzi?

What does chemotx choice depend on in these organisms?

Back 10

CNS

Myocardium

whether the infection has gotten into the CNS.

Front 11

Which two drugs are used to tx both forms of african sleeping sickness if they haven't reached the CNS?

Back 11

Suramin and Pentamidine

Front 12

Suramine:
- admin?
- mech?
- toxicities?
- used in?

Back 12

- IV
- unclear
- CNS, urticaria, pruritis, nepthrotoxicity
- African sleeping sickness that hasn't made it to the CNS

Front 13

Pentamidine:
- admin?
- mech?
- toxicities?
- cleared quickly or slowly?
- used in?

Back 13

- IM
- b/kinetoplast DNA of mitochondria
- hypotension, nausea, vomiting, renal & hepatic damage
- v. slowly (months)
- African sleeping sickness that hasn't made it to the CNS

Front 14

Which drug is used to tx both forms of african sleeping sickness if they get to the CNS?
- admin?
- mech? specific or non?
- SEs?

Back 14

Melarsoprol
- IV in hospital
- reacts with sulfhydrl groups
+ not very
- myocardial damage, HTN, peripheral neuropathy

Front 15

What is Elfornithine? Mech? Advantages?

Back 15

newer drug that shows some promise in african sleeping sickness tx.

Ornithine decarboxylase inhibitor

Somewhat less toxic than the alternatives

Front 16

What drug is used to tx Chagas dz?
- admin?
- mech?
- SE?
- organ of clearance?

Back 16

Nifurtimox
- only orally
- generates free rads
- anorexia, nausea, rashes, HA
- kidneys

Front 17

What can be used to treat Leishmania donovani (leshmaniasis?)?

Back 17

Stibogluconate
- highly toxic compound

Front 18

What is the most prevalent parasitic infestation of humans? (general category)

Most infections of this sort are tx'ed with what?

Back 18

Round worms

Mebendazole

Front 19

Mebendazole
- admin?
- area of effects?
- contraindications?
- SEs?

Back 19

- oral
- largely intraluminal
- pregnancy
- not many, stays luminally

Front 20

The following medications can be used to treat what, even though they aren't usually the 1st choice?

Albendazole
Pyrantel pamoate

Back 20

Roundworm infestations

Front 21

How do you tx Schistosomiasis?
- admin?
- SE?
- mech?

Back 21

praziquantel
- orally
- RARE... sedation, ab discomfort, fever, sweating, nausea, HA, eosinophilia
- contractionand paralysis of worm's muscle by ^^Ca mem permeability

Front 22

In tx of tapeworms, it is important to determine whether the ___ has been eliminated, since it can regenerate the proglottids.

Back 22

scolex

Front 23

What is the most common tapeworm? Prevalent population/Geographic area?

Back 23

hymenolepis nana (dwarf tapeworm)

SE USA in kids

Front 24

What is the drug of choice for most tapeworms?

What about for T. Solium (exception)? Why?

Back 24

niclosamide

praziquantel
- niclosamide cannot kill the ova released from the proglottids... which can get into the CNS and cause bad shit.