Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Spring 2025 Therapeutics V > Exam 5 Antimalarial and Antiparastic Drugs > Flashcards

Exam 5 Antimalarial and Antiparastic Drugs Flashcards

(83 cards)

Start Studying
1
Q

Who is most commonly affected by lice (pediculosis)?

A

Children age 3-11

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the most common symptom of lice?

A

Itching
-from allergic reaction to bites

-note that it is often asymptomatic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Adult lice live for how long?

A

About 30 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are nits?

A

Lice eggs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Nits take how long to hatch?

A

6-9 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Only one treatment option will kill unhatched eggs in addition to live lice, what is it?

A

Spinosad

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Since only one treatment option kills both live and unhatched lice, what do we do when treating with the others?

A

Patients normally need 2 treatments

-the second occurs 9-10 days later to kill newly hatched lice before they lay eggs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the 2 OTC options for lice?

A

Pyrethrins

Pyrethroids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Who should we be careful using pyrethrins and pyrethroids in?

A

Patients with chrysanthemum and ragweed allergies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How is spinosad therapy administered?

A

Topically

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the MOA of spinosad?

A

Nicotinic acetylcholine receptor agonist

Causes rapid excitation of the insect’s nervous system and death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the MOA of the Perethrins?

A

Nerve membrane sodium channel toxins that do not affect potassium channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the scientific name of pinworms?

A

Enterobiasis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Who is most likely to get pinworms?

A

School-aged children

Institutionalized persons

Household members or caretakers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How are pinworms transmitted?

A

Fecal-oral route

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How do we diagnose pinworms?

A

Tape test

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the 2 benzimidazoles used for pinworms/helminths?

A

Mebendazole
Albendazole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Albendazole is useful for what types of infections?

A

Helminth GI and tissue infections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the MOA of the benzimidazoles?

A

Bind to tubulin

Inhibit formation of microtubules by capping them
-prevent addition from the plus end while they are still actively shrinking from the minus end
-microtubule gets very short

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the drug of choice for pinworms?

A

Albendazole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How is albendazole activated?

A

Rapidly converted to albendazole sulfoxide
-active metabolite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Which drug acts as a broad-spectrum anti-helminth?

A

Pyrantel pamoate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Which drug is available OTC for pinworms?

A

Pyrantel pamoate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What consideration with Pyrantel pamoate’s absorption makes it a good option for pinworms?

A

It is highly insoluble

-this improves use in intestinal infections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is the MOA of Pyrantel pamoate?
Depolarizing neuromuscular blocking agent Causes release of acetylcholine and inhibits cholinesterase *Worms are paralyzed and expelled*
26
What are the 2 most common organisms that cause malaria?
Plasmodium falciparum *most deaths* Plasmodium vivax
27
Which types of malaria can cause relapses?
*Plasmodium vivax Plasmodium ovale
28
How does Plasmodium vivax cause relapses?
Hypnozoites in the liver can stay dormant for months and then come back
29
What are the 3 classifications of antimalarial drugs?
Tissue schizonticides Blood schizonticides Gametocytocides
30
What do the Tissue schizonticides do?
Kill liver stage parasites
31
What do the Blood schizonticides do?
Kill erythrocytic forms
32
What do Gametocytocides do?
Kill sexual stages Block transmission*
33
What are the 4 main antimalarial drug classes?
Artemisinin 4-aminoquinolones 8-aminoquinolones Antibiotics
34
What part of the Artemisinin structure is important for its function?
The endoperoxide bridge
35
How is artemisinin activated?
Likely via heme-iron in the food vacuole
36
What is the MOA of artemisinin?
Must be activated through heme-iron in the food vacuole MOA: -Activated artemisinin may form free radicals -Alkylates parasite components (proteins, lipids, DNA) -Triggers unfolded protein response -Inhibits translation, proteasome, mitochondria -May inhibit phosphatidylinositol-3-kinase (PfPI3K) (not an accepted hypothesis)
37
What type of drug is Artemisinin?
Blood schizonticide
38
Artemisinin is not active against which stages of malaria?
Liver stage Hypnozoites (dormant)
39
What is a draw-back to Artemisinin therapy?
Has a very short half-life (1-2h) -commonly is paired with longer half-life drugs -artemisinin provides the knockdown and the other drug eliminates the remaining parasites
40
What is the active form of artemisinin?
Dihydroartemisinin
41
What is the mechanism of resistance against artemisinin?
Mutations in Kelch 13 gene -this causes parasites to progress through the life cycle more slowly so they are in the ring phase longer -the parasite holds out until artemisinin is gone with its short half-life
42
What drug is a 4-aminoquinoline?
Chloroquine
43
How do malaria parasites metabolize hemoglobin?
Malaria parasites ingest hemoglobin from the host cell -Degrade hemoglobin to amino acid and free heme in the food vacuole *Free heme is toxic* -The parasite polymerizes the heme into hemozoin which is nontoxic
44
How can 4-aminoquinolines (quinine and chloroquine) result in a build-up of toxic heme?
They accumulate in the food vacuole and inhibit heme polymerization by the malaria organism -this prevents conversion of toxic free heme to the hemozoin nontoxic form
45
How does resistance against 4-aminoquinolones occur?
Lack of accumulation in the food vacuole
46
Which drug has been the drug of choice for malaria since the 1940's?
Chloroquine -hydroxychloroquine is the same thing with an extra hydroxy group
47
Which drug is an 8-aminoquinoline?
Primaquine
48
Primaquine is the drug of choice for what forms of malaria?
Liver stages (BOTH actively growing and hypnozoites*) -of P. vivax and P. ovale
49
How is primaquine activated?
CYP450 2D6 in humans
50
What is the only drug that Primaquine should be used in combination with?
Chloroquine
51
What is the MOA of Primaquine?
Step 1: Hydroxylation by CYP2D6 Step 2: Spontaneous oxidation to quinoneimines -Human cytochrome P450 NADPH: oxoreductase (CPR) reduces quinoneimines back to OH-PQm to create a catalytic cycle of H2O2 production -H2O2 kills plasmodium parasites
52
What are the side effects of Primaquine?
High Risk of hemolysis in patients with G6PD deficiency
53
What do we need to check patients for before starting Primaquine?
G6PD normal levels
54
What is the role of Doxycycline as an antimalarial drug?
Blood schizonticide (kills erythrocyte forms)
55
What is the MOA of doxycycline for malaria?
Targets components of the apicoplast (plant-like organelle carrying out many essential biochemical processes)
56
What are the 2 most common forms of resistance against malaria?
Chloroquine Resistance Artemisinin Resistance
57
What are the 3 places with low rates of chloroquine resistance?
Regions in Central America west of the Panama Canal Haiti Dominican Republic
58
How are we preventing artemisinin resistance?
Artemisinin-based drugs are used in combination
59
What are the available malaria vaccines?
RTS,S/AS01 R21/Matrix-M
60
Who should receive the Malaria vaccines?
Children living in regions with moderate to high Plasmodium falciparum Start dosing at 5 months of age
61
What is the recommended prophylaxis for all malaria-endemic regions?
Atovaquone/Proguanil Doxycycline Tafenoquine
62
What is the recommended prophylaxis for regions primarily with P. vivax?
Primaquine
63
What is the recommended prophylaxis for regions with chloroquine-sensitive malaria?
Chloroquine Hydroxychloroquine
64
What is the recommended prophylaxis for regions with mefloquine-sensitive malaria?
Mefloquine
65
What are the primary symptoms of malaria?
Fever AND Has traveled to a malaria endemic region before fever onset
66
How long after the mosquito bite do symptoms of malaria occur?
2-4 weeks is typical Up to 3 years after exposure if P. vivax or P. ovale
67
How do we diagnose malaria?
Giemsa-stained blood smear *standard -do both a thick and a thin smear
68
What is a thick smear used for in malaria diagnosis?
Used to estimate parasite density
69
What is a thin smear used for in malaria diagnosis?
Used to determine the Plasmodium species
70
How many times should we perform and check a blood smear for malaria diagnosis?
Check every 12-24 hours and run 3 times to rule out malaria
71
Patients have severe malaria if they have one or more of the following:
Impaired consciousness/coma Hemoglobin <7 AKI Acute respiratory distress syndrome (ARDS) Circulatory collapse/shock Acidosis Disseminated intravascular coagulation Parasite density >/= 5%
72
Severe malaria is typically caused by what type of malaria?
P. falciparum
73
What are the 3 treatment options for uncomplicated malaria (chloroquine resistance present or unknown)?
Artemether-Lumefantrine (Coartem) Atovaquone-Proguanil (Malarone) Quinine Sulfate + Doxycycline/Tetracycline/Clindamycin
74
What is the treatment of choice for uncomplicated malaria, chloroquine resistance present, no mefloquine resistance, or unknown resistance?
Mefloquine *note that this should be treated as last line *2-dose regimen
75
What are the 2 treatment options for uncomplicated malaria in a chloroquine sensitive region?
Chloroquine Hydroxychloroquine
76
What are the treatment options for anti-relapse treatment of P. vivax and P. ovale infections?
Primaquine phosphate Tafenoquine *Need G6PD testing for both of these*
77
What is the only time that Tafenoquine can be used for anti-relapse therapy?
If chloroquine was used already for treatment
78
What is the preferred P. falciparum treatment?
Artemether-lumefantrine preferred Unless there is no chloroquine resistance, then: Chloroquine or Hydroxychloroquine
79
What is the preferred P. ovale or P. vivax treatment?
Artemether-Lumefantrine preferred + Anti-relapse drug: Primaquine (after G6PD therapy) Unless there is no chloroquine resistance, then: Chloroquine or Hydroxychloroquine + Anti relapse drug: Primaquine or Tafenoquine
80
What is the preferred P. knowlesi or P. malariae treatment?
Hydroxychloroquine or Chloroquine
81
How often should blood smears be performed with severe malaria?
Every 12-24 hours until negative
82
What is the treatment for severe malaria?
IV artesunate then transition to oral therapy: -Artemether-lumefantrine* -Atovaquone proguanil -Quinine + Doxy/Clinda -Mefloquine
83
What is the main side effect of Artesunate?
Delayed hemolytic anemia

Spring 2025 Therapeutics V (41 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions