126 terms

P'Col2- Antiprotozoals & Antihelminthics

Malaria is caused by ______ parasites.
What are the 4 plasmodium parasites that cause malaria?
What is the vector of malaria?
female anopheles mosquito
Symptoms of malaria
fever, shivering, pain in the joints, HA, repeated vomiting, convulsions, coma
What are the 2 forms of reporduction for malarial parasites?
asexual and sexual
Which type of life cycle occurs in humans?
_______ are introduced into the host through mosquito bite.
Where do sporozoites travel as soon as they are introduced into the host?
liver-- hepatocytes
Once in the liver, sporozoites develop into ______.
Schizonts in hepatocytes eventually turn into _____.
Merozoites then gon on to infect _______.
red blood cells
In the red blood cells, the parasites form motile ______.
The trophozoites then form _____ and eventually _____.
The merozoites formed in RBCs then go on to infect ________.
other RBCs
All of the sporozoites, merozoites, schizonts, and trophozoites constitute the _________ cycle.
Dormant ______ liberate merozoites months to years later.
When dorman hypnozoites liberate merozoites months to years later, this is called the _______ stage.
Dormant hypnozoites are not present in ______.
P. falciparum
P. malariae
Periodic episodes of fever result from synchronized rupture of RBC's releasing _____.
The rise in temp during perioidic episodes of fever is due to ______.
increased tumor necrosis factor -a
Tertian Malaria is aka _______.
every third day malria
Tertian Malaria is caused by ____.
_____ causes benign tertian malaria.
_____ causes malignant tertian malaria.
P. falciparum
Drugs used for acute attack of malaria act on the _______.
parasites in the blood
Drugs used for prophylaxis act on ______.
merozoites emerging from liver cells
Drugs used for radical cure act on _____.
parasites in the liver
Drugs used for transmission prevention by mosquitos act on ________.
_____ agents act on erythrocytic forms of the plasmodium.
Blood schizonticidal
Blood schizonticidal agents act on _____ forms of the plasmodium.
Blood schizonticidal agents may cure malaria caused by ________.
P. falciparum
P. malariae
Tissue schizonticidal agents may cure malaria caused by ________.
P. vivax
P. ovale
Drugs used to treat acute attack
Artemisinin, quinoline-methanols, atovaquone, dapsone, pyrimethamine, and proguanil
What are the quinoline-methanols?
quinine, mefloquine, chloroquine
Drugs that interfere with folate synthesis
dapsone, pyrimethamine, proguanil
Drugs that affect mitochondrial function
Blood schizonticidal agents are typically used in combo with what?
doxycycline, tetracycline, or clindamycin
Tissue schizonticidal agents provide a _____ cure.
How do tissue schizonticidal agents work?
they destroy gametocytes, preventing transmission
Drugs used for chemoprophylaxis kill parasites when?
when they emerge from the liver after the pre-erythrocytic stage
Drugs for chemoprophylaxis of malaria are given to patients traveling to malaria endemic areas. Administration should start when?
1 week prior to entering area
How long should malaria prophylaxis continue?
Continue throughout visit and 1 month after returning home
Drugs used for chemoprophylaxis include:
Chloroquine, Malarone, Mefloquine, Doxycycline, Primaquine
______ is used for areas without resistant P.falciparum.
_____ is used in areas with chloroquine-resistant p.falciparum
Malarone and Mefloquine
_______ is used for P.vivax and P.ovale infections.
Drugs used to prevent transmission destroy ______
What drugs are used to prevent transmission?
Primaquine, Proguanil, Pyrimethamine
Which drugs inhibit dihydrofolate reductase?
Pyrimethamine and Proguanil
Pyrimethamine is commonly used in combo with what?
sulfadoxine and dapsone
ADRs for Pyrimethamine-dapsone
hemolytic anemia, agranulocytosis, lung inflammation
ADRs for Pyrimethamine-sulfadoxine
blood dyscrasias, allergic rxns, megaloblastic anemia
Chloroquine does not affect _______.
sporozoites, hypnozoites, or gametocytes
Chloroquine is effective against which plasmodial species?
all 4
Chloroquine MOA
At neutral pH: diffuses freely into the parasite lysosome
At acidic pH of lysosome: converted to a protonated form and trapped.
-Inhibition of hem polymerase which poisons the parasites & prevents utilization of amino acids from hemoglobin proteolysis
Chloroquine resistance
-Enhanced efflux
______ is resistant to Chloroquine in most parts of the world.
P. falciparum
Chloroquine ADRs
nausea, vomiting, dizziness, blurred vision, HA, urticarial sx, retiophathies, hearing loss, dysrhythmias
Quinine is derived from what?
cinchona bark
Quinine is effective against _____ forms of all 4 species of plasmodium.
Quinine is not effective on ______ forms.
Quinine MOA
similar to that of Chloroquine
Quinine is the main therapeutic agent for ______.
P. falciparum
Quinine ADRs
cinchonism, hypotension, dysrhythmias, delirium, bone marrow depression, hypoglycemia
Mefloquine is effective against ______.
Mefloquine MOA
similar to Chloroquine & Quinine
Mefloquine ADRs
GI disturbances, confusion, dysphoria, neuropsychiatric reactions
Lumefantrine is used in combo with ________.
Lumefantrine MOA
similar to that of chloroquine, quinine, and Mefloquine
Primaquine is active against ______zoites.
Primaquine eradicates _____.
P.vivax and P.ovale
_______ is most effective for preventing transmission in all 4 plasmodium species.
Primaquine does not affect ______ stage.
erythrocytic stage ( so no sporozoites and such)
What are the analogues of primaquine?
Etaquine and Tafenoquine
Is Primaquine or it's analogues more active?
analogues (Etaquine and Tafenoquine)
Primaquine ADRs
GI effects, methemoglobinemia, hemolysis in glucose 6-phosphate dehydrogenase deficient patients
Artemisinin is derived from _____.
chinese herb ging hao
What are the Artemisinin synthetics?
Artemether and arether
What is the advantage to Artemisinin synthetics?
higher activity and better absorption
Artemisinin is effective for _______.
acute attack of malaria
Artemisinin MOA
inhibits parasite Calcium dependent ATPase
Artemisinin based combo therapy is standard for _________.
uncomplicated falciparum malaria
Atavoquone is active against ________ schizonts.
tissue and blood erythrocytic
Atavoquone MOA
disruption of mitochondrial electron transport
Atavoquone is alternative therapy for _____.
P. jiroveci infection
Atavoquone is used for tx and prophylaxis of _______.
falciparum malaria in combo w/ atovaquone & proguanil
1st line for Chloroquine-sensitive P. falciparum and P. malariae
Chloroquine phosphate
1st line for P.vivax and P.ovale infections
Chloroquine then Primaquine
1st line for Uncomplicated Chloroquine-resistant P.falciparum
Quinine plus Doxycylcine or Clindamycin
1st line for severe or complicated P.falciparum
Artensunate with Doxycycline or Clindamycine
Amebiasis is an infection with ________.
Entamoeba histolytica
Tx options for Amebiasis
Metronidazole, Iodoquinol, Paromomycin, Pentamidine, Diioxanide furoate, and sodium stibogluconate
______ is DOC for tx of extraluminal amebiasis.
Metronidazole MOA
activated by anaerobic organisms then damages parasite DNA
What are the luminal amebicides?
Iodoquinol, Diloxanide furoate, Paromomycin sulfate
Luminal amebicides are not active against ______.
Benzimidazole MOA
selectively inhibit polymerization of beta-tubulin
Praziquantel MOA
increase the permeability of cell membranes to calcium resulting in paralysis & death
Pyrantel Pamoate MOA
depolarizing neuromuscular blockade resulting in paralysis & expulsion of worm
Ivermectin MOA
paralyzes nematodes & arthropods
______ is the DOC for Giardiasis and Trichomoniasis.
______ is DOC for tissue infections with E. histolytica.
Metronidazole or Tinidazole
Tinidazole may be effective for ________ if Metronidazole resistant.
Metronidazole ADRs
metallic, bitter taste; GI disturbance; dizziness, HA, sensory neuropathis, disulfram-like effect (nasuea and vomiting if alcohol is ingested)
Which is better tolerated: Metronidazole or Tinidazole?
Luminal amebicides are commonly used with ________.
Which antihelminthic can be used to treat T. saginata and T. solium?
_______ is the DOG for an asymptomatic infected amebiasis patient.
Diloxanide furoate
Emetine & Dehydroemetine are effective against tissue _______.
Emetine & Dehydroemetine use is limited to _________.
severe amebiasis when metronidazole not an option
Tx for acute invasive intestinal amebiasis
Metronidazole followed by diloxanide
Tx for chronic intestinal amebiasis
Tx for hepatic amebiasis
Tx for the carrier state of amebiasis
Which benzimidazole is rapidly absorbed from the GI?
Mebendazole & Albendazole should be taken on an empty stomach when?
When used for intraluminal parasites
Mebendazole & Albendazole should be taken with a fatty meal when?
when used for tissue parasites
Benzimidazole uses
Ascariasis, Trichuriasis, hookworm, pinworm, Hydatid disease, Neurocysticercosis
Most toxic Benzimidazole
What is the DOC for Schistosomiasis?
Piperazine is used in tx of ________.
Piperazine MOA
Inhibits neuromuscular transmission in the worm & causes paralysis of ascaris
Pyrantel Pamoate is active mainly against ________.
luminal organisms
Two uses for Ivermectin
Ivermectin ADRs
fever, HA, dizziness, drowsiness, weakness, joint & muscle pain, decreased BP, increased HR, edema
Avoid Ivermectin use with ______.
barbituates, benzodiazepines, and valproic acid