Chapter 25- Parasitic infections

Which parasite types are targeted in this chapter’s drug therapy?
A. Bacteria and viruses
B. Protozoa, helminths, mites, and lice
C. Fungi and prions
D. Mycobacteria and spirochetes

Protozoa, helminths, mites, and lice

Which statement about vaccines for human parasites is correct?
A. Several vaccines exist for malaria and giardiasis
B. No licensed vaccines exist for human parasites
C. Vaccines are available only for helminths
D. Vaccines are used only in children

No licensed vaccines exist for human parasites

A hallmark symptom of pinworm (Enterobius vermicularis) infection is:
A. Hemoptysis
B. Perianal pruritus
C. Jaundice
D. Photophobia

Perianal pruritus

Fish tapeworms can cause which deficiency?
A. Iron
B. Vitamin C
C. Vitamin B12 (megaloblastic anemia)
D. Vitamin D

Vitamin B12 (megaloblastic anemia)

Early symptoms of malaria most closely resemble:
A. Seasonal allergies
B. Influenza‑like illness
C. Appendicitis
D. Pancreatitis

Influenza‑like illness

In untreated P. falciparum malaria, severe illness can develop within:
A. 2 hours
B. 12 hours
C. 24 hours
D. 72 hours

24 hours

The classic periodicity of acute malarial paroxysms typically occurs every:
A. 8–12 hours
B. 24–36 hours
C. 36–72 hours
D. 96–120 hours

36–72 hours

Women with trichomoniasis typically present with:
A. Odorless clear discharge
B. Foul‑smelling yellow‑gray frothy discharge with itching/burning
C. Bloody discharge without odor
D. Asymptomatic presentation always

Foul‑smelling yellow‑gray frothy discharge with itching/burning

SATA: Key clinical issues in chronic giardiasis may include:
A. Weight loss
B. Large foul‑smelling stools
C. Vitamin B12, folate, fat‑soluble vitamin deficiencies
D. Hyperglycemia
E. Flatulence

Weight loss, Large foul‑smelling stools, Vitamin B12, folate, fat‑soluble vitamin deficiencies, Flatulence

Prototype amebicide effective in intestinal and extraintestinal disease is:
A. Chloroquine only
B. Metronidazole
C. Tetracycline
D. Doxycycline

Metronidazole

Chloroquine is categorized in amebiasis therapy as a(n):
A. Luminal amebicide
B. Tissue (extraintestinal) amebicide
C. Systemic antibacterial
D. Antifungal

Tissue (extraintestinal) amebicide

Tetracycline/doxycycline aid in amebiasis by:
A. Directly killing trophozoites in the liver
B. Altering intestinal bacterial flora required for amebic viability
C. Increasing host acidity
D. Stimulating motility

Altering intestinal bacterial flora required for amebic viability

Metronidazole oral absorption is approximately:
A. 20%
B. 40%
C. 60%
D. 80%

80%

Metronidazole distributes well into all of the following except:
A. CSF
B. Bone
C. Hepatic abscesses
D. Aqueous humor only

Aqueous humor only

Black Box Warning for metronidazole/tinidazole emphasizes:
A. Risk of tendon rupture
B. Carcinogenicity in rats—use only for indicated conditions
C. Severe hepatotoxicity is universal
D. QT prolongation always occurs

Carcinogenicity in rats—use only for indicated conditions

Metronidazole is not FDA‑approved for:
A. Intestinal amebiasis
B. Bacterial vaginosis
C. Prophylaxis of amebiasis
D. Trichomoniasis

Prophylaxis of amebiasis

In pregnancy, metronidazole has been associated with:
A. Neural tube defects
B. Cleft lip with or without cleft palate when used in 1st trimester
C. Limb defects
D. No risks

Cleft lip with or without cleft palate when used in 1st trimester

After a single 2 g dose of metronidazole, breastfeeding should be withheld for:
A. 2–4 hours
B. 6–8 hours
C. 12–24 hours
D. 48–72 hours

12–24 hours

Key counseling while taking metronidazole includes avoiding:
A. Dairy products
B. Alcohol and alcohol‑containing meds
C. Caffeine
D. Vitamin B12

Alcohol and alcohol‑containing meds

A classic metronidazole adverse effect is:
A. Photophobia
B. Metallic taste
C. Gingival hyperplasia
D. Tinnitus only

Metallic taste

Concomitant metronidazole and warfarin can:
A. Decrease INR
B. Increase bleeding tendency
C. Cause hypoglycemia
D. Prevent thrombosis reliably

Increase bleeding tendency

Disulfiram + alcohol + metronidazole may lead to:
A. Bradycardia and hypothermia
B. Tachycardia, flushing, N/V (disulfiram‑like reaction)
C. Severe hypertension
D. Hypoglycemia

Tachycardia, flushing, N/V (disulfiram‑like reaction)

For trichomoniasis, the nurse evaluates therapy primarily by:
A. Increased vaginal discharge
B. Decreased vaginal drainage and odor
C. Rising WBC count
D. Development of fever

Decreased vaginal drainage and odor

Nitazoxanide for protozoal diarrhea should be taken:
A. On an empty stomach at bedtime
B. With food
C. With antacids only
D. With dairy only

With food

Tinidazole’s common adverse effect is:
A. Constipation
B. Bitter metallic taste with nausea
C. Photosensitivity
D. Cough

Bitter metallic taste with nausea

Chloroquine is most effective against which stage?
A. Exoerythrocytic liver hypnozoites
B. Erythrocytic forms
C. Sporozoites in mosquito
D. Gametocytes exclusively

Erythrocytic forms

Due to widespread resistance, chloroquine is less useful for treatment of:
A. P. vivax
B. P. falciparum in most endemic regions
C. P. malariae
D. P. ovale

P. falciparum in most endemic regions

Primaquine acts mainly against:
A. Erythrocytic forms only
B. Exoerythrocytic (tissue) forms to prevent recurrence
C. Only gametocytes of P. falciparum
D. Sporozoites in humans

Exoerythrocytic (tissue) forms to prevent recurrence

Chloroquine MOA includes all except:
A. Inhibits DNA/RNA polymerase
B. Raises internal pH of parasite acid vesicles
C. Inhibits prostaglandin effects
D. Directly inhibits folate synthesis

Directly inhibits folate synthesis

For malaria prophylaxis, chloroquine should be taken:
A. Daily starting day of travel
B. Weekly, same day each week, starting 1–2 weeks before and 4 weeks after travel
C. Monthly only during travel
D. Only if fever occurs

Weekly, same day each week, starting 1–2 weeks before and 4 weeks after travel

Chloroquine adverse effects can include:
A. Retinal damage and focusing difficulty
B. Profound hyperkalemia
C. Severe hypoglycemia
D. Stevens‑Johnson syndrome (universal)

Retinal damage and focusing difficulty

Children are especially sensitive to which compound class within chloroquine products?
A. 4‑aminoquinolines
B. Tetracyclines
C. Macrolides
D. Nitroimidazoles

4‑aminoquinolines

SATA: Important chloroquine teaching includes:
A. Take with food to reduce GI distress
B. Eye exams at initiation and every 3 months
C. Avoid urine‑acidifying foods (cranberries, prunes, plums, cheeses, meats, fish, eggs, grains)
D. Double dose if you vomit once
E. Take the same time each dosing day

Take with food to reduce GI distress, Eye exams at initiation and every 3 months, Avoid urine‑acidifying foods (cranberries, prunes, plums, cheeses, meats, fish, eggs, grains), Take the same time each dosing day

Which increases chloroquine effects?
A. Cimetidine
B. Magnesium trisilicate
C. Vitamin C
D. Dairy

Cimetidine

Which decreases chloroquine effects?
A. Cimetidine
B. Magnesium trisilicate
C. Vitamin C (by increasing urinary excretion)
D. B and C

Magnesium trisilicate, Vitamin C (by increasing urinary excretion)

Artemether/lumefantrine (Coartem) pearls include:
A. Avoid with QT prolongation; take with food; repeat dose if vomiting within 2 hours
B. Safe with grapefruit juice
C. Take on empty stomach
D. Only for prophylaxis

Avoid with QT prolongation; take with food; repeat dose if vomiting within 2 hours

Atovaquone/proguanil (Malarone) is used for:
A. Treatment only
B. Prevention and treatment, including chloroquine‑resistant strains
C. Prophylaxis only
D. Severe malaria IV therapy

Prevention and treatment, including chloroquine‑resistant strains

Hydroxychloroquine differs from chloroquine primarily by:
A. No risk to eyes
B. Fewer adverse effects overall with similar uses
C. Only works for P. falciparum
D. Cannot be used with primaquine

Fewer adverse effects overall with similar uses

Mefloquine carries a Black Box Warning for:
A. Tendon rupture
B. Severe neuropsychiatric reactions; avoid in major psychiatric disorders
C. Severe hemolysis in G6PD deficiency
D. Stevens‑Johnson syndrome

Severe neuropsychiatric reactions; avoid in major psychiatric disorders

Before prescribing primaquine, screen for:
A. HLA‑B*5701
B. G6PD deficiency
C. TPMT deficiency
D. HIV

G6PD deficiency

Primaquine is not effective for:
A. Preventing recurrent P. vivax/ovale
B. Treating acute attacks of malaria
C. Preventing initial occurrence (with suppressive agent after travel)
D. Radical cure of hypnozoites

Treating acute attacks of malaria

Prototype anthelmintic (benzimidazole) is:
A. Ivermectin
B. Mebendazole
C. Praziquantel
D. Niclosamide

Mebendazole

Mebendazole MOA:
A. Calcium channel blockade in worms
B. Blocks glucose uptake \rightarrow depletes glycogen \rightarrow worm death
C. Inhibits folate pathway
D. Inhibits protease

Blocks glucose uptake \rightarrow depletes glycogen \rightarrow worm death

Mebendazole coverage includes all except:
A. Pinworm
B. Whipworm
C. Roundworm
D. Schistosoma haematobium

Schistosoma haematobium

Taking mebendazole with food will:
A. Decrease serum levels
B. Increase serum levels
C. Cause toxicity universally
D. Have no effect

Increase serum levels

Administration instructions for mebendazole include:
A. Swallow whole only
B. Chew or crush and mix with food or liquid
C. Only IV
D. Sublingual

Chew or crush and mix with food or liquid

SATA: Significant mebendazole adverse effects can include:
A. Agranulocytosis and leukopenia
B. Elevated AST/ALT
C. Seizures
D. Severe hyperglycemia
E. GI upset (N/V/D, abdominal pain)

Agranulocytosis and leukopenia, Elevated AST/ALT, Seizures, GI upset (N/V/D, abdominal pain)

Which decreases mebendazole serum concentration?
A. Carbamazepine
B. Metronidazole
C. Cimetidine
D. Warfarin

Carbamazepine

Which increases toxic effects when combined with mebendazole?
A. Phenytoin
B. Aminoquinolines
C. Metronidazole
D. Vitamin C

Metronidazole

Albendazole absorption is increased by:
A. High‑fat meal
B. Empty stomach
C. Dairy restriction
D. Antacids

High‑fat meal

Triclabendazole caution:
A. Always IV only
B. Use cautiously with QT‑prolonging medications
C. Contraindicated in all liver disease
D. Must be taken fasting

Use cautiously with QT‑prolonging medications

Ivermectin is most active against:
A. Strongyloidiasis; also used orally for resistant lice
B. Schistosomiasis only
C. Tapeworm only
D. Hookworm only

Strongyloidiasis; also used orally for resistant lice

Permethrin is first‑line for:
A. Only head lice
B. Only scabies
C. Both head lice and scabies
D. Neither

Both head lice and scabies

Permethrin MOA:
A. Inhibits calcium influx in parasite neurons
B. Inhibits sodium influx \rightarrow delayed repolarization \rightarrow paralysis/death
C. Inhibits potassium efflux
D. Opens chloride channels

Inhibits sodium influx \rightarrow delayed repolarization \rightarrow paralysis/death

Standard permethrin head lice application time before rinsing is:
A. 5 minutes
B. 10 minutes
C. 30 minutes
D. Overnight

10 minutes

Standard permethrin scabies application is left on for:
A. 30–60 minutes
B. 2–4 hours
C. 8–14 hours
D. 24 hours

8–14 hours

Permethrin use in pregnancy:
A. Contraindicated
B. Recommended by CDC for pubic lice and scabies in pregnancy
C. Only second‑line
D. Only oral route is allowed

Recommended by CDC for pubic lice and scabies in pregnancy

SATA: Common local adverse effects of permethrin include:
A. Pruritus and erythema
B. Burning/tingling/numbness at application site
C. Scalp edema/pain
D. Anaphylaxis universally
E. Rash

Pruritus and erythema, Burning/tingling/numbness at application site, Scalp edema/pain, Rash

Contraindications for permethrin include hypersensitivity to:
A. Chrysanthemums, pyrethroids, pyrethrins
B. Penicillins
C. Sulfonamides
D. Macrolides

Chrysanthemums, pyrethroids, pyrethrins

Lindane is:
A. First‑line for pediculosis/scabies with no safety issues
B. Second‑line; BBW for neurotoxicity (seizures/death), avoid in premature infants and uncontrolled seizure disorders
C. Safe in infants <2 months
D. Only shampoo with no systemic absorption risk

Second‑line; BBW for neurotoxicity (seizures/death), avoid in premature infants and uncontrolled seizure disorders