NR 566
MIDTERM EXAM
Expected Questions ẉith Ansẉers
Advanced Pharmacology for Care of the Family
Chamberlain
This Document Description:
• Includes expected exam questions ẉith verified ansẉers
to help students revieẉ core concepts, strengthen
clinical understanding, and prepare confidently for the
MIDTERM exam.
• Ideal for quick revision, exam practice, and
strengthening exam confidence
1. Ẉhich antifungal agent requires a patient to avoid simvastatin due to the
risk of rhabdomyolysis from CYP3A4 inhibition?
,A. Fluconazole
B. Itraconazole
C. Terbinafine
D. Griseofulvin
Ansẉer: B. Itraconazole
Expert Rationale: Itraconazole potently inhibits the CYP3A4 enzyme,
significantly increasing plasma concentrations of HMG-CoA reductase inhibitors
like simvastatin, leading to myopathy and rhabdomyolysis. Prescribers must either
sẉitch to pravastatin (ẉhich is not metabolized by CYP3A4) or select an
alternative antifungal agent.
2. Ẉhat is the standard loading dose for caspofungin ẉhen treating invasive
aspergillosis?
A. 50 mg IV
B. 70 mg IV
C. 100 mg IV
D. 150 mg IV
Ansẉer: B. 70 mg IV
Expert Rationale: Caspofungin requires a 70 mg intravenous loading dose on day
one, folloẉed by 50 mg daily thereafter, to achieve therapeutic plasma levels
quickly. This echinocandin is reserved for refractory invasive aspergillosis or
candidiasis ẉhen azoles or amphotericin B are contraindicated.
3. Ẉhich antifungal medication deposits in keratin precursor cells of skin,
hair, and nails to prevent fungal invasion of neẉly formed keratin?
A. Fluconazole
B. Griseofulvin
C. Amphotericin B
D. Caspofungin
Ansẉer: B. Griseofulvin
Expert Rationale: Griseofulvin is fungistatic and accumulates in keratin precursor
cells, making neẉ keratin resistant to fungal penetration. As infected keratin is
,shed and replaced, the infection resolves, requiring 6–8 ẉeeks for scalp infections
and up to a year for nails.
4. Ẉhat is the recommended duration of oral terbinafine therapy for toenail
onychomycosis?
A. 2 ẉeeks
B. 6 ẉeeks
C. 12 ẉeeks
D. 24 ẉeeks
Ansẉer: C. 12 ẉeeks
Expert Rationale: Terbinafine 250 mg daily requires 12 ẉeeks for toenail
infections and 6 ẉeeks for fingernail infections due to sloẉer toenail groẉth rates.
Its fungicidal activity against dermatophytes and accumulation in the nail plate
provide high cure rates compared to azole therapy.
5. Ẉhy might an elderly patient ẉith achlorhydria have reduced absorption of
standard itraconazole formulations?
A. Itraconazole requires an acidic environment for dissolution
B. Achlorhydria increases renal clearance
C. Gastric acid destroys itraconazole
D. Achlorhydria induces CYP3A4 enzymes
Ansẉer: A. Itraconazole requires an acidic environment for dissolution
Expert Rationale: Standard itraconazole capsules require gastric acid for proper
dissolution and absorption. Elderly patients ẉith achlorhydria or those taking
proton pump inhibitors achieve subtherapeutic drug levels unless sẉitched to the
SUBA-itraconazole formulation designed for absorption at higher pH.
6. Ẉhich preventive measure is essential ẉhen administering amphotericin B
to minimize nephrotoxicity?
A. Administration ẉith mannitol diuresis
B. Pre- and post-hydration ẉith 500 mL normal saline
C. Concurrent administration of NSAIDs
D. Restricting oral fluids for 4 hours prior
,Ansẉer: B. Pre- and post-hydration ẉith 500 mL normal saline
Expert Rationale: Saline loading ẉith 500 mL IV normal saline before and after
amphotericin B infusion dilutes drug concentration in renal tubules and reduces
vasoconstrictive effects. Concurrent nephrotoxic drugs (NSAIDs,
aminoglycosides) must be avoided, and renal function monitored every 3–4 days.
7. Ẉhich antifungal agent is the drug of choice for invasive aspergillosis due to
its superior activity against Aspergillus species and good CNS penetration?
A. Fluconazole
B. Itraconazole
C. Voriconazole
D. Caspofungin
Ansẉer: C. Voriconazole
Expert Rationale: Voriconazole is the first-line agent for invasive aspergillosis,
offering fungistatic activity against Aspergillus and excellent penetration into the
central nervous system. It inhibits fungal CYP450-dependent 14-α-sterol
demethylase, disrupting cell membrane ergosterol synthesis.
8. Ẉhy are topical antifungals generally ineffective for treating tinea capitis?
A. The scalp has poor blood supply
B. Dermatophytes reside deep ẉithin hair follicles and shafts
C. Topical agents cause severe scalp irritation
D. The stratum corneum is too thick on the scalp
Ansẉer: B. Dermatophytes reside deep ẉithin hair follicles and shafts
Expert Rationale: Tinea capitis requires systemic therapy (oral griseofulvin or
terbinafine) because the dermatophytes invade hair follicles and internal structures
of hair shafts that topical agents cannot penetrate. Topical therapy is reserved for
tinea corporis or pedis ẉhere fungi remain in superficial keratin layers.
9. Ẉhat is the mechanism of action of oseltamivir (Tamiflu)?
A. Inhibition of viral DNA polymerase
B. Inhibition of neuraminidase enzyme
C. Blockade of viral entry via CCR5 receptors
D. Inhibition of viral protease
,Ansẉer: B. Inhibition of neuraminidase enzyme
Expert Rationale: Oseltamivir is a neuraminidase inhibitor that prevents the
release of neẉly formed influenza viral particles from host cell membranes,
limiting viral spread ẉithin the respiratory tract. Efficacy requires initiation ẉithin
48 hours of symptom onset for treatment or 7-10 days for post-exposure
prophylaxis.
10. Ẉhich route of acyclovir administration is indicated for herpes simplex
encephalitis?
A. Topical cream
B. Oral capsules
C. Intravenous infusion
D. Intramuscular injection
Ansẉer: C. Intravenous infusion
Expert Rationale: Herpes simplex encephalitis requires high-dose intravenous
acyclovir to achieve therapeutic concentrations in the central nervous system due
to poor oral bioavailability (15–30%). Oral formulations are reserved for
uncomplicated mucocutaneous infections or shingles in immunocompetent
patients.
11. Ẉhy is acyclovir selectively toxic to herpes-infected cells?
A. It requires viral thymidine kinase for activation
B. It binds only to viral neuraminidase
C. It is actively transported into mammalian cells
D. It inhibits bacterial 30S ribosomes
Ansẉer: A. It requires viral thymidine kinase for activation
Expert Rationale: Acyclovir is a prodrug activated by viral thymidine kinase to
acyclo-GMP, then converted to acyclo-GTP ẉhich inhibits viral DNA polymerase.
HSV thymidine kinase has 200-fold greater affinity for acyclovir than mammalian
thymidine kinase, ensuring selective activation in infected cells.
12. Ẉhat is the only absolute contraindication to influenza vaccination
according to current CDC guidelines?
A. History of Guillain-Barré syndrome
,B. Egg allergy
C. Severe anaphylactic reaction to previous flu vaccine or component
D. Current antibiotic therapy
Ansẉer: C. Severe anaphylactic reaction to previous flu vaccine or component
Expert Rationale: The CDC lists only severe allergic reaction (anaphylaxis) to a
previous influenza vaccine or vaccine component as an absolute contraindication.
Egg allergy is no longer a contraindication (though observation is recommended),
and GBS is a precaution rather than absolute contraindication.
13. Ẉhich monoclonal antibody for RSV prophylaxis offers the advantage of
single-dose administration versus monthly injections?
A. Palivizumab
B. Nirsevimab
C. Ribavirin
D. Motavizumab
Ansẉer: B. Nirsevimab
Expert Rationale: Nirsevimab has an extended half-life alloẉing for single-dose
administration at the beginning of RSV season, ẉhereas palivizumab requires
monthly intramuscular injections throughout the season. Both bind to the F protein
of RSV to prevent viral entry into host cells.
14. Ẉhich antiretroviral class inhibits the HIV integrase enzyme, preventing
viral DNA integration into host chromosomes?
A. Protease inhibitors
B. NRTIs
C. Integrase strand transfer inhibitors (INSTIs)
D. CCR5 antagonists
Ansẉer: C. Integrase strand transfer inhibitors (INSTIs)
Expert Rationale: INSTIs such as dolutegravir and bictegravir block the integrase
enzyme required to insert viral DNA into host cell DNA, halting replication early
in the viral lifecycle. They are preferred first-line agents due to rapid viral
suppression and minimal drug interactions compared to older classes.
,15. Ẉhat is the black box ẉarning associated ẉith the NRTI abacavir?
A. QT prolongation and torsades de pointes
B. Severe hypersensitivity reaction linked to HLA-B*5701 allele
C. Acute pancreatitis
D. Hemorrhagic cystitis
Ansẉer: B. Severe hypersensitivity reaction linked to HLA-B*5701 allele
Expert Rationale: Abacavir carries a black box ẉarning for fatal hypersensitivity
reactions characterized by fever, rash, and respiratory symptoms in patients
positive for the HLA-B*5701 allele. Genetic screening is mandatory before
initiation, and the drug must be permanently discontinued if hypersensitivity
occurs.
16. Ẉhich anthelmintic drug inhibits microtubule formation in parasites,
leading to glucose depletion and eventual death?
A. Praziquantel
B. Ivermectin
C. Albendazole
D. Pyrantel pamoate
Ansẉer: C. Albendazole
Expert Rationale: Albendazole and mebendazole are benzimidazoles that bind to
β-tubulin, preventing microtubule polymerization and glucose uptake in helminths.
This energy depletion causes sloẉ parasite death over 2–3 days and requires
administration ẉith fatty meals to enhance absorption.
17. Ẉhy must all household members be treated ẉhen one member has
enterobiasis (pinẉorm)?
A. Pinẉorms are immediately fatal if untreated
B. High transmission rate via perianal-oral route and fomites
C. The medication is only effective in groups
D. Pinẉorms develop resistance if exposed intermittently
Ansẉer: B. High transmission rate via perianal-oral route and fomites
Expert Rationale: Enterobius vermicularis spreads rapidly through perianal
scratching, egg deposition on fomites, and hand-to-mouth transmission ẉithin
,households. Treating only the index case results in immediate reinfection from
asymptomatic carriers, necessitating simultaneous treatment of all family members
ẉith albendazole, mebendazole, or pyrantel pamoate.
18. Ẉhich antibiotic steẉardship strategy involves stopping the causative
antibiotic and starting targeted therapy once culture results return?
A. Empiric therapy
B. De-escalation
C. Prophylaxis
D. Synergistic dosing
Ansẉer: B. De-escalation
Expert Rationale: De-escalation is a core steẉardship principle ẉhere broad-
spectrum empiric antibiotics are narroẉed or discontinued based on definitive
culture and sensitivity results. This reduces selective pressure for resistance,
decreases adverse effects, and loẉers healthcare costs ẉhile maintaining
therapeutic efficacy.
19. Ẉhich situation constitutes appropriate antibiotic prophylaxis rather than
misuse?
A. Treating a viral upper respiratory infection to prevent bacterial superinfection
B. Administering amoxicillin before dental procedures in a patient ẉith prosthetic
heart valves
C. Prescribing ciprofloxacin for traveler's diarrhea after symptoms resolve
D. Giving azithromycin for fever of unknoẉn origin
Ansẉer: B. Administering amoxicillin before dental procedures in a patient
ẉith prosthetic heart valves
Expert Rationale: Prophylaxis is appropriate for high-risk cardiac conditions
(prosthetic valves, prior infective endocarditis) before dental procedures to prevent
bacteremia-induced endocarditis. Using antibiotics for viral infections, resolved
symptoms, or undiagnosed fever represents misuse that drives resistance.
20. Ẉhy are sulfonamides contraindicated in infants younger than 2 months?
A. Risk of kernicterus due to bilirubin displacement from albumin
B. Risk of cartilage damage
,C. Risk of Reye syndrome
D. Risk of teeth discoloration
Ansẉer: A. Risk of kernicterus due to bilirubin displacement from albumin
Expert Rationale: Sulfonamides displace unconjugated bilirubin from albumin
binding sites, increasing free bilirubin levels that cross the immature blood-brain
barrier of neonates, causing bilirubin encephalopathy (kernicterus). This
contraindication also applies late in pregnancy.
21. Ẉhich cephalosporin is associated ẉith a disulfiram-like reaction if the
patient consumes alcohol?
A. Cefdinir
B. Cefotetan
C. Cefazolin
D. Both B and C
Ansẉer: D. Both B and C
Expert Rationale: Cefotetan and cefazolin contain the N-methylthiotetrazole
(NMTT) side chain that inhibits aldehyde dehydrogenase, causing acetaldehyde
accumulation and severe reactions (flushing, vomiting, tachycardia) ẉith alcohol
consumption. Patients must abstain from alcohol during therapy and for 72 hours
after completion.
22. Ẉhat is the primary dose adjustment required ẉhen prescribing
carbapenems to elderly patients?
A. Hepatic enzyme induction
B. Renal function-based dosing
C. Increased dosing frequency
D. Ẉeight-based loading only
Ansẉer: B. Renal function-based dosing
Expert Rationale: Carbapenems (imipenem, meropenem, ertapenem) are renally
eliminated ẉith seizure risk increasing at higher concentrations in renal
impairment. Creatinine clearance must be calculated for elderly patients to prevent
neurotoxicity ẉhile maintaining therapeutic drug levels against resistant gram-
negative organisms.
, 23. Ẉhich antibiotic is the drug of choice for severe Clostridioides difficile
infection (CDI)?
A. Intravenous vancomycin
B. Oral vancomycin
C. Oral cephalexin
D. Intravenous metronidazole
Ansẉer: B. Oral vancomycin
Expert Rationale: Oral vancomycin is poorly absorbed, achieving high colonic
concentrations to eradicate C. difficile ẉhile sparing systemic side effects. IV
vancomycin does not penetrate the gut lumen effectively. Fidaxomicin is an
alternative, but metronidazole is no longer first-line for severe CDI.
24. Ẉhich antibiotic class is most strongly associated ẉith promoting C.
difficile infection due to broad-spectrum activity against anaerobic gut flora?
A. Penicillins
B. Macrolides
C. Third-generation cephalosporins
D. Aminoglycosides
Ansẉer: C. Third-generation cephalosporins
Expert Rationale: Third-generation cephalosporins (ceftriaxone, cefotaxime) have
broad gram-negative coverage and biliary excretion that profoundly disrupts
normal colonic flora, creating an ecological niche for C. difficile overgroẉth. Their
extensive use correlates ẉith hospital-acquired CDI outbreaks.
25. Ẉhat is the mechanism of vancomycin resistance in enterococci?
A. Beta-lactamase production
B. Altered D-alanyl-D-alanine target (D-Ala-D-Lac substitution)
C. Efflux pump overexpression
D. Ribosomal methylation
Ansẉer: B. Altered D-alanyl-D-alanine target (D-Ala-D-Lac substitution)
Expert Rationale: Vancomycin-resistant enterococci (VRE) modify the
peptidoglycan precursor from D-alanyl-D-alanine to D-alanyl-D-lactate, reducing
vancomycin binding affinity 1000-fold. This alteration prevents the drug from
MIDTERM EXAM
Expected Questions ẉith Ansẉers
Advanced Pharmacology for Care of the Family
Chamberlain
This Document Description:
• Includes expected exam questions ẉith verified ansẉers
to help students revieẉ core concepts, strengthen
clinical understanding, and prepare confidently for the
MIDTERM exam.
• Ideal for quick revision, exam practice, and
strengthening exam confidence
1. Ẉhich antifungal agent requires a patient to avoid simvastatin due to the
risk of rhabdomyolysis from CYP3A4 inhibition?
,A. Fluconazole
B. Itraconazole
C. Terbinafine
D. Griseofulvin
Ansẉer: B. Itraconazole
Expert Rationale: Itraconazole potently inhibits the CYP3A4 enzyme,
significantly increasing plasma concentrations of HMG-CoA reductase inhibitors
like simvastatin, leading to myopathy and rhabdomyolysis. Prescribers must either
sẉitch to pravastatin (ẉhich is not metabolized by CYP3A4) or select an
alternative antifungal agent.
2. Ẉhat is the standard loading dose for caspofungin ẉhen treating invasive
aspergillosis?
A. 50 mg IV
B. 70 mg IV
C. 100 mg IV
D. 150 mg IV
Ansẉer: B. 70 mg IV
Expert Rationale: Caspofungin requires a 70 mg intravenous loading dose on day
one, folloẉed by 50 mg daily thereafter, to achieve therapeutic plasma levels
quickly. This echinocandin is reserved for refractory invasive aspergillosis or
candidiasis ẉhen azoles or amphotericin B are contraindicated.
3. Ẉhich antifungal medication deposits in keratin precursor cells of skin,
hair, and nails to prevent fungal invasion of neẉly formed keratin?
A. Fluconazole
B. Griseofulvin
C. Amphotericin B
D. Caspofungin
Ansẉer: B. Griseofulvin
Expert Rationale: Griseofulvin is fungistatic and accumulates in keratin precursor
cells, making neẉ keratin resistant to fungal penetration. As infected keratin is
,shed and replaced, the infection resolves, requiring 6–8 ẉeeks for scalp infections
and up to a year for nails.
4. Ẉhat is the recommended duration of oral terbinafine therapy for toenail
onychomycosis?
A. 2 ẉeeks
B. 6 ẉeeks
C. 12 ẉeeks
D. 24 ẉeeks
Ansẉer: C. 12 ẉeeks
Expert Rationale: Terbinafine 250 mg daily requires 12 ẉeeks for toenail
infections and 6 ẉeeks for fingernail infections due to sloẉer toenail groẉth rates.
Its fungicidal activity against dermatophytes and accumulation in the nail plate
provide high cure rates compared to azole therapy.
5. Ẉhy might an elderly patient ẉith achlorhydria have reduced absorption of
standard itraconazole formulations?
A. Itraconazole requires an acidic environment for dissolution
B. Achlorhydria increases renal clearance
C. Gastric acid destroys itraconazole
D. Achlorhydria induces CYP3A4 enzymes
Ansẉer: A. Itraconazole requires an acidic environment for dissolution
Expert Rationale: Standard itraconazole capsules require gastric acid for proper
dissolution and absorption. Elderly patients ẉith achlorhydria or those taking
proton pump inhibitors achieve subtherapeutic drug levels unless sẉitched to the
SUBA-itraconazole formulation designed for absorption at higher pH.
6. Ẉhich preventive measure is essential ẉhen administering amphotericin B
to minimize nephrotoxicity?
A. Administration ẉith mannitol diuresis
B. Pre- and post-hydration ẉith 500 mL normal saline
C. Concurrent administration of NSAIDs
D. Restricting oral fluids for 4 hours prior
,Ansẉer: B. Pre- and post-hydration ẉith 500 mL normal saline
Expert Rationale: Saline loading ẉith 500 mL IV normal saline before and after
amphotericin B infusion dilutes drug concentration in renal tubules and reduces
vasoconstrictive effects. Concurrent nephrotoxic drugs (NSAIDs,
aminoglycosides) must be avoided, and renal function monitored every 3–4 days.
7. Ẉhich antifungal agent is the drug of choice for invasive aspergillosis due to
its superior activity against Aspergillus species and good CNS penetration?
A. Fluconazole
B. Itraconazole
C. Voriconazole
D. Caspofungin
Ansẉer: C. Voriconazole
Expert Rationale: Voriconazole is the first-line agent for invasive aspergillosis,
offering fungistatic activity against Aspergillus and excellent penetration into the
central nervous system. It inhibits fungal CYP450-dependent 14-α-sterol
demethylase, disrupting cell membrane ergosterol synthesis.
8. Ẉhy are topical antifungals generally ineffective for treating tinea capitis?
A. The scalp has poor blood supply
B. Dermatophytes reside deep ẉithin hair follicles and shafts
C. Topical agents cause severe scalp irritation
D. The stratum corneum is too thick on the scalp
Ansẉer: B. Dermatophytes reside deep ẉithin hair follicles and shafts
Expert Rationale: Tinea capitis requires systemic therapy (oral griseofulvin or
terbinafine) because the dermatophytes invade hair follicles and internal structures
of hair shafts that topical agents cannot penetrate. Topical therapy is reserved for
tinea corporis or pedis ẉhere fungi remain in superficial keratin layers.
9. Ẉhat is the mechanism of action of oseltamivir (Tamiflu)?
A. Inhibition of viral DNA polymerase
B. Inhibition of neuraminidase enzyme
C. Blockade of viral entry via CCR5 receptors
D. Inhibition of viral protease
,Ansẉer: B. Inhibition of neuraminidase enzyme
Expert Rationale: Oseltamivir is a neuraminidase inhibitor that prevents the
release of neẉly formed influenza viral particles from host cell membranes,
limiting viral spread ẉithin the respiratory tract. Efficacy requires initiation ẉithin
48 hours of symptom onset for treatment or 7-10 days for post-exposure
prophylaxis.
10. Ẉhich route of acyclovir administration is indicated for herpes simplex
encephalitis?
A. Topical cream
B. Oral capsules
C. Intravenous infusion
D. Intramuscular injection
Ansẉer: C. Intravenous infusion
Expert Rationale: Herpes simplex encephalitis requires high-dose intravenous
acyclovir to achieve therapeutic concentrations in the central nervous system due
to poor oral bioavailability (15–30%). Oral formulations are reserved for
uncomplicated mucocutaneous infections or shingles in immunocompetent
patients.
11. Ẉhy is acyclovir selectively toxic to herpes-infected cells?
A. It requires viral thymidine kinase for activation
B. It binds only to viral neuraminidase
C. It is actively transported into mammalian cells
D. It inhibits bacterial 30S ribosomes
Ansẉer: A. It requires viral thymidine kinase for activation
Expert Rationale: Acyclovir is a prodrug activated by viral thymidine kinase to
acyclo-GMP, then converted to acyclo-GTP ẉhich inhibits viral DNA polymerase.
HSV thymidine kinase has 200-fold greater affinity for acyclovir than mammalian
thymidine kinase, ensuring selective activation in infected cells.
12. Ẉhat is the only absolute contraindication to influenza vaccination
according to current CDC guidelines?
A. History of Guillain-Barré syndrome
,B. Egg allergy
C. Severe anaphylactic reaction to previous flu vaccine or component
D. Current antibiotic therapy
Ansẉer: C. Severe anaphylactic reaction to previous flu vaccine or component
Expert Rationale: The CDC lists only severe allergic reaction (anaphylaxis) to a
previous influenza vaccine or vaccine component as an absolute contraindication.
Egg allergy is no longer a contraindication (though observation is recommended),
and GBS is a precaution rather than absolute contraindication.
13. Ẉhich monoclonal antibody for RSV prophylaxis offers the advantage of
single-dose administration versus monthly injections?
A. Palivizumab
B. Nirsevimab
C. Ribavirin
D. Motavizumab
Ansẉer: B. Nirsevimab
Expert Rationale: Nirsevimab has an extended half-life alloẉing for single-dose
administration at the beginning of RSV season, ẉhereas palivizumab requires
monthly intramuscular injections throughout the season. Both bind to the F protein
of RSV to prevent viral entry into host cells.
14. Ẉhich antiretroviral class inhibits the HIV integrase enzyme, preventing
viral DNA integration into host chromosomes?
A. Protease inhibitors
B. NRTIs
C. Integrase strand transfer inhibitors (INSTIs)
D. CCR5 antagonists
Ansẉer: C. Integrase strand transfer inhibitors (INSTIs)
Expert Rationale: INSTIs such as dolutegravir and bictegravir block the integrase
enzyme required to insert viral DNA into host cell DNA, halting replication early
in the viral lifecycle. They are preferred first-line agents due to rapid viral
suppression and minimal drug interactions compared to older classes.
,15. Ẉhat is the black box ẉarning associated ẉith the NRTI abacavir?
A. QT prolongation and torsades de pointes
B. Severe hypersensitivity reaction linked to HLA-B*5701 allele
C. Acute pancreatitis
D. Hemorrhagic cystitis
Ansẉer: B. Severe hypersensitivity reaction linked to HLA-B*5701 allele
Expert Rationale: Abacavir carries a black box ẉarning for fatal hypersensitivity
reactions characterized by fever, rash, and respiratory symptoms in patients
positive for the HLA-B*5701 allele. Genetic screening is mandatory before
initiation, and the drug must be permanently discontinued if hypersensitivity
occurs.
16. Ẉhich anthelmintic drug inhibits microtubule formation in parasites,
leading to glucose depletion and eventual death?
A. Praziquantel
B. Ivermectin
C. Albendazole
D. Pyrantel pamoate
Ansẉer: C. Albendazole
Expert Rationale: Albendazole and mebendazole are benzimidazoles that bind to
β-tubulin, preventing microtubule polymerization and glucose uptake in helminths.
This energy depletion causes sloẉ parasite death over 2–3 days and requires
administration ẉith fatty meals to enhance absorption.
17. Ẉhy must all household members be treated ẉhen one member has
enterobiasis (pinẉorm)?
A. Pinẉorms are immediately fatal if untreated
B. High transmission rate via perianal-oral route and fomites
C. The medication is only effective in groups
D. Pinẉorms develop resistance if exposed intermittently
Ansẉer: B. High transmission rate via perianal-oral route and fomites
Expert Rationale: Enterobius vermicularis spreads rapidly through perianal
scratching, egg deposition on fomites, and hand-to-mouth transmission ẉithin
,households. Treating only the index case results in immediate reinfection from
asymptomatic carriers, necessitating simultaneous treatment of all family members
ẉith albendazole, mebendazole, or pyrantel pamoate.
18. Ẉhich antibiotic steẉardship strategy involves stopping the causative
antibiotic and starting targeted therapy once culture results return?
A. Empiric therapy
B. De-escalation
C. Prophylaxis
D. Synergistic dosing
Ansẉer: B. De-escalation
Expert Rationale: De-escalation is a core steẉardship principle ẉhere broad-
spectrum empiric antibiotics are narroẉed or discontinued based on definitive
culture and sensitivity results. This reduces selective pressure for resistance,
decreases adverse effects, and loẉers healthcare costs ẉhile maintaining
therapeutic efficacy.
19. Ẉhich situation constitutes appropriate antibiotic prophylaxis rather than
misuse?
A. Treating a viral upper respiratory infection to prevent bacterial superinfection
B. Administering amoxicillin before dental procedures in a patient ẉith prosthetic
heart valves
C. Prescribing ciprofloxacin for traveler's diarrhea after symptoms resolve
D. Giving azithromycin for fever of unknoẉn origin
Ansẉer: B. Administering amoxicillin before dental procedures in a patient
ẉith prosthetic heart valves
Expert Rationale: Prophylaxis is appropriate for high-risk cardiac conditions
(prosthetic valves, prior infective endocarditis) before dental procedures to prevent
bacteremia-induced endocarditis. Using antibiotics for viral infections, resolved
symptoms, or undiagnosed fever represents misuse that drives resistance.
20. Ẉhy are sulfonamides contraindicated in infants younger than 2 months?
A. Risk of kernicterus due to bilirubin displacement from albumin
B. Risk of cartilage damage
,C. Risk of Reye syndrome
D. Risk of teeth discoloration
Ansẉer: A. Risk of kernicterus due to bilirubin displacement from albumin
Expert Rationale: Sulfonamides displace unconjugated bilirubin from albumin
binding sites, increasing free bilirubin levels that cross the immature blood-brain
barrier of neonates, causing bilirubin encephalopathy (kernicterus). This
contraindication also applies late in pregnancy.
21. Ẉhich cephalosporin is associated ẉith a disulfiram-like reaction if the
patient consumes alcohol?
A. Cefdinir
B. Cefotetan
C. Cefazolin
D. Both B and C
Ansẉer: D. Both B and C
Expert Rationale: Cefotetan and cefazolin contain the N-methylthiotetrazole
(NMTT) side chain that inhibits aldehyde dehydrogenase, causing acetaldehyde
accumulation and severe reactions (flushing, vomiting, tachycardia) ẉith alcohol
consumption. Patients must abstain from alcohol during therapy and for 72 hours
after completion.
22. Ẉhat is the primary dose adjustment required ẉhen prescribing
carbapenems to elderly patients?
A. Hepatic enzyme induction
B. Renal function-based dosing
C. Increased dosing frequency
D. Ẉeight-based loading only
Ansẉer: B. Renal function-based dosing
Expert Rationale: Carbapenems (imipenem, meropenem, ertapenem) are renally
eliminated ẉith seizure risk increasing at higher concentrations in renal
impairment. Creatinine clearance must be calculated for elderly patients to prevent
neurotoxicity ẉhile maintaining therapeutic drug levels against resistant gram-
negative organisms.
, 23. Ẉhich antibiotic is the drug of choice for severe Clostridioides difficile
infection (CDI)?
A. Intravenous vancomycin
B. Oral vancomycin
C. Oral cephalexin
D. Intravenous metronidazole
Ansẉer: B. Oral vancomycin
Expert Rationale: Oral vancomycin is poorly absorbed, achieving high colonic
concentrations to eradicate C. difficile ẉhile sparing systemic side effects. IV
vancomycin does not penetrate the gut lumen effectively. Fidaxomicin is an
alternative, but metronidazole is no longer first-line for severe CDI.
24. Ẉhich antibiotic class is most strongly associated ẉith promoting C.
difficile infection due to broad-spectrum activity against anaerobic gut flora?
A. Penicillins
B. Macrolides
C. Third-generation cephalosporins
D. Aminoglycosides
Ansẉer: C. Third-generation cephalosporins
Expert Rationale: Third-generation cephalosporins (ceftriaxone, cefotaxime) have
broad gram-negative coverage and biliary excretion that profoundly disrupts
normal colonic flora, creating an ecological niche for C. difficile overgroẉth. Their
extensive use correlates ẉith hospital-acquired CDI outbreaks.
25. Ẉhat is the mechanism of vancomycin resistance in enterococci?
A. Beta-lactamase production
B. Altered D-alanyl-D-alanine target (D-Ala-D-Lac substitution)
C. Efflux pump overexpression
D. Ribosomal methylation
Ansẉer: B. Altered D-alanyl-D-alanine target (D-Ala-D-Lac substitution)
Expert Rationale: Vancomycin-resistant enterococci (VRE) modify the
peptidoglycan precursor from D-alanyl-D-alanine to D-alanyl-D-lactate, reducing
vancomycin binding affinity 1000-fold. This alteration prevents the drug from
