iPTX 3 exam 4 - Parasitic Infections

what are the 3 main classes of parasites?

Protozoa, Helminths, Ectoparasites

what is the transmission of Protozoa like?

Fecal-oral route, arthropod vector

what is the transmission of helminths like?

Fecal-oral route

what is the tranmission of ectoparaistes like?

Arthropod vector

What are the 3 groups of parasitic infections that the CDC focuses on?

Malaria, neglected tropical diseases, parasitic infections within the US

T or F:

Malaria is the highest risk of mortality

True

what are the risk factors for Amebiasis?

travel or immigration from area from poor sanitation, people who have anal sex

what are the S/sx of amebiasis?

asympomatic; diarrhea, abdominal pain and cramping, amebic dysentery and extraintestinal disease

what is the treatment of amebiasis that is asymptomatic?

Paramomycin

what is the treatment of amebiasis for mild-to-mod?

Flagyl, followed by paramomycin

what is the preferred treatment for extraluminal disease of amebiasis?

metronidazole

what is the dosing for paramomycin in amebiasis?

weight-based dosing; 25 - 35 mg/kg/day in 3 divided dose

T or F:

You need to administer food with paramomycin

True

what is the dosing for Flagyl for amebiasis?

500 - 750 mg TID with food

What if a patient has a Child-pugh class C for their liver, what dosing of Flagyl do you give for amebiasis?

375 mg TID

What is the MoA of Tinidazole?

cytotoxic mechanism through damaging DNA crosslinking

T or F:

There is no renal or hepatic dose adjustments for Tinidazole

True

what are the risk factors for Giardia?

Traveling to areas with poor sanitation, immunocompromised, people who have anal sex

what is the clinical presentation of Giardia?

diarrhea, gas, foul-smelling, greasy poop, Nausea, dehydration

When is treatment of asymptomatic patients with Giardia recommended?

To groups of vulnerable patients to help prevent the spread of infection

What are the treatments for symptomatic Giardia patients?

Nitazoxanide 500 mg PO BID x 3 days

Tinidazole 2000 mg PO once

Metronidazole 500 mg PO BID OR 250 mg TID x 5 - 7 days

what is the MoA of Nitazoxanide?

interference with pyruvate (Ferredoxin oxidoreductase; PFOR) for anaerobic metabolism

T or F:

There is renal or hepatic dose adjustments for Nitazoxanide

False

what are the risk factors of Cyclospora?

Living or traveling to tropic or subtropics, seasonal

what is the clinical presentation for cyclospora?

watery diarrhea, loss of appetite

what is the preferred treatment for cyclospora?

Bactrim

what is the immunocompetent dosing for Bactrim for Cyclospora?

1 DS PO BID x 7 - 10 days

what ist he immunocompromised dosing for Bactrim for Cyclospora

1 DS PO BID for 2 - 4 weeks

what is the alternative medication that treats cyclospora?

Nitazoxanide 500 mg PO BID x 7 days

what CrCl do you adjust Bactrims dosing at?

< 30 mL/min

what are the risk factors of Hookworms?

Warm/moist climates, poor sanitary conditions, walking barefoot in soil

what is the clinical presentation of Hookworms?

asymptomatic, abdominal pain, diarrhea, weight loss/loss of appetite

what is the preferred treatment for Hookworms?

Albendazole 400 mg PO once; take with food

what are the alternative treatments for Hookworms?

Mebendazole, Pyrantel pamoate

what should be given as an adjunctive treatment with Albendazole?

Iron supplements

What is the MoA of Albendazole?

causes degeneration of cytoplasmic microtubule in intestinal and tegmental cells of helminths

T or F:

There is no renal and hepatic dose adjustments for Albendazole

True

What is the MoA of Mebendazole?

Blocks glucose reuptake and inhibits the formation of helminth microtubules

what is the dosing for Pyrantel Pamoate?

11 mg/kg PO

what are the risk factors for round worms?

Traveling to tropical regions, live/work in rural, warm climates/agriculture, sanitation facilities, LTCF

what is the clinical presentation of Roundworms?

Asymptomatic, abdominal pain, bloating, heartburn, dry cough

what is the gold standard for diagnosing roundworms?

Serialized stool exam

what is the treatment for Roundworms?

Ivermectin 200 mcg/kg x 1 - 2 days; repeat in 2 weeks if a pt is immunocompromised

what is the dosing for ivermectin?

Weight-based dosing; 200 mcg/kg

comes in 3 mg tablets

What are the early symptoms of malaria?

Fever, flu-like illness, chills, HA, muscle aches, fatigue, N/V/D

what are the severe symptoms of malaria?

Kidney failure, seizures, altered cognition, loss of consciousness

what is the gold standard of malaria diagnosis?

microscopy blood smears

what are the two types of blood smears for malaria?

Thick smear, Thin smear

What are thick smears?

More efficient in detecting parasites

what are thin smears?

more efficient in detection of morphology

if a patient tests negative blood smear for malaria, what do you do?

Repeart a blood smear every 12-24 hours for a total of 3 times

If a patient tests positive blood smear for malaria, what do you do?

Calculate parasite density and determine the species

what drug is indicated for the treatment of acute, uncomplicated malaria due to P. falciparum?

Arthemether-Lumefantrine (Coartem)

what drug is indicated for the initial treatment of severe malaria?

Artesunate

What is the duration of therapy for Artesunate?

Until the patient is able to tolerate PO therapy

what drug is indicated for the treatment of uncomplicated malaria due to strains of P. falciparum, P. Malariae, P. ovale, and P. vivax?

Chloroquine, Hydroxychloroquine

what is the dosing regimen for Artesunate?

2.4 mg/kg at 0 hours, 12 hours, 24 hours, then daily

T or F:

you need to adminster Artesunate as a slow bolus over 1-2 mins

True