Term
| Which antiparasitic below has the broadest spectrum of activity? |
|
Definition
| Albendazole (out of one Albendazole, Thiabendazole, Mebendazole) |
|
|
Term
|
Definition
• Occurs in over 100 countries
• More than 40% of the world’s population is at risk
• Estimated 300–500 million cases of malaria
occur each year
• One million people die from malaria each year
• Young children are at most risk for death
• 1,200 cases occur in the U.S. each year
- Almost all are imported from abroad via travelers or
immigrants from affected areas of the world |
|
|
Term
|
Definition
• Female anopheles mosquito
inoculates the Plasmodium
sporozoite to initiate infection
• Sporozoites invade
hepatocytes; exoerythrocytic
stage schizonts mature in
the liver
• Merozoites released from
the liver and invade RBCs
• Parasites develop into
trophozoites to schizonts to
merozoites
- Only erythrocytic
parasites cause clinical
illness |
|
|
Term
| Plasmodium falciparum and P. malariae |
|
Definition
only
cause one cycle of liver infection
• Liver infection ceases spontaneously in four weeks
• Medications which attack the erythrocytic parasites
will cure the infection |
|
|
Term
|
Definition
a dormant liver stage,
hypnozoite, is not eradicated by most drugs
• Relapses can occur
• Need another agent to deal with hepatic parasites |
|
|
Term
| Antimalarials Chloroquine |
|
Definition
• 4-aminoquinolone
• Active against erythrocytic
phases of susceptible
Plasmodium spp.
- Mechanism of action:
• Concentrated in the acidic
vacuoles of the
intraerythrocytic parasites
• Inhibits a heme polymerase
which protects the parasite
from ferriprotoporphyrin IX
(which damages cell
membranes) |
|
|
Term
|
Definition
• Due to the decreased
uptake of chloroquine into
the digestive vacuole
- Linked to a specific
transporter membrane
protein in the vacuole’s
membrane • Inhibited by calcium channel blockers
• Resistance arose
independently in many
areas of the world |
|
|
Term
• Side effects
• Headache, N/V, dizziness, confusion |
|
Definition
|
|
Term
• First successful agent
to treat malaria
• Cinchona alkaloid
• Acts rapidly against the
erythrocytic stages
of malaria
• Used for treatment of
chloroquine-resistant
malaria
• Mechanism of action:
- Unknown |
|
Definition
|
|
Term
• Metabolism
• Liver; prolonged clearance in patients with
malaria |
|
Definition
|
|
Term
Poorest therapeutic index of all
antimalarials
• Cinchonism
- Tinnitus, headache, N/V
- Dose-related; reversible
• Less commonly
- Rash, bone marrow suppression, massive
hemolysis in P. falciparum (blackwater fever) |
|
Definition
|
|
Term
|
Definition
• Quinolone-methanol derivative of quinine
- Blood schizonticidal drug
• Used mainly for malarial prophylaxis
- Single weekly dose
• Effective in treatment of chloroquineresistant
P. falciparum |
|
|
Term
• Toxicity
• Neuropsychiatric effects
- Psychosis, seizures, anxiety
• N/V, vivid dreams
• Cardiac conduction
disturbances |
|
Definition
|
|
Term
• Useful in treatment of acute P. falciparum
malaria in areas with resistance
- Used in combination with quinine
• Also useful for malarial prophylaxis in
chloroquine resistant regions and other
agents such as mefloquine are not
an option
•-Problem of phototoxicity |
|
Definition
|
|
Term
| • Proguanil (chloroguanide) moa |
|
Definition
• Inhibits dihydrofolate reductase
Proguanil/Atovaquone (Malarone®) |
|
|
Term
• Toxicity
• Well tolerated; N/V; diarrhea at high doses |
|
Definition
Proguanil (chloroguanide)
Proguanil/Atovaquone (Malarone®) |
|
|
Term
|
Definition
• Hydroxynaphthoquinone
• Uncouples oxidative metabolism
• High relapse rate when used as monotherapy
for malaria treatment
Proguanil/Atovaquone (Malarone®) |
|
|
Term
| • Well tolerated: rare rash, N/V |
|
Definition
• Atovaquone
Proguanil/Atovaquone (Malarone®) |
|
|
Term
| Proguanil/Atovaquone (Malarone®) |
|
Definition
• Fixed dose combination
• Proguanil 100 mg and atovaquone 250 mg
• Well tolerated
• One tablet daily for prophylaxis
• Useful in chloroquine resistant areas for
prophylaxis and treatment
• Expensive compared to other prophylactic
agents
• Resistance has become an issue in Africa and
Southeast Asia
-malaria treatment |
|
|
Term
| Treatment of Intestinal Nematodes |
|
Definition
• Thiabendazole
• Mebendazole
• Albendazole
- All synthetic benzimidazole molecules
- Albendazole has the broadest activity |
|
|
Term
|
Definition
extremely broad
• Ascariasis, roundworm
- A. lumbricoides
• Hookworm
- A. duodenale, N. americanus
• Whipworm
- T. trichuris
• Pinworm
- E. vermicularis
• Cutaneous larval migrans
• Echinococcosis
- Liver hydatid cysts • 1/3 cured with albendazole alone
• Neurocysticercosis
- Due to T. solium • Pork tapeworm’s larval stage in the
brain
- Reduces seizure rate and
hastens resolution of cysts |
|
|
Term
Albendazole
• Mechanism of action: |
|
Definition
• Inhibits microtubule synthesis in nematodes,
which impairs glucose uptake by the organism
• Larvicidal in hydatid disease,
neurocysticercosis, ascariasis, and hookworm
• Ovicidal in ascariasis, hookworm, and
whipworm |
|
|
Term
• Toxicity
• N/V; rarely rash |
|
Definition
|
|
Term
|
Definition
• Derivative of ivermectin B1, a macrocyclic
lactone produced by S. avermitilis
• Active against nematodes and arthropod
ectoparasites |
|
|
Term
• Drug of choice for human
onchocerciasis (river
blindness)
• Kills microfilariae in the skin
and reduces burden in the
eye
• Drug of choice for
strongyloidiasis |
|
Definition
|
|
Term
• Useful in the
treatment of scabies
• An ectoparasite
• Especially crusted
(Norwegian) scabies |
|
Definition
|
|
Term
| Ivermectin Mechanism of action: |
|
Definition
Potentiates the opening of glutamate gated chloride
channels that are only found in nematodes and
arthropods |
|
|
Term
• Toxicity
• Well tolerated
• Death of microfilaria can cause fever, pruritis,
arthralgia, myalgia |
|
Definition
|
|
Term
Metronidazole
• Active against |
|
Definition
• Entamoeba histolytica
- Amoebic liver abscess
• Giardia lamblia
- Giardiasis
• Trichomonas vaginalis
- Trichomoniasis |
|
|
Term
|
Definition
• Concentrates within the parasite and acts
as an electron sink as well as directly
damages DNA due to free radicals |
|
|
