APHA NAPLEX (ACTUAL 2025/2026) QUESTIONS AND
VERIFIED ANSWERS
When 2 anti-infective therapies together produce a greater
effect than the effects of each used alone, this phenomenon is
termed
A. commensalism
B. synergy
C. antagonism
D. additive
E. interacting ----Answers----B. Synergy
Analysis of the cerebrospinal fluid may give valuable clues to
the identity of the pathogen in meningitis. Given the following
results, what would be indicative of a bacterial infx?
I. increased WBCs
II. increased glucose
III. increased protein
A. I only
B. II only
C. I and III only
,D. II and III only
E. all of the above ----Answers----C. Bacterial meningitis infx
show an increase in WBC and proteins in the CSF. Glucose is
decreased
Empiric therapy for meningitis for pts up to 1mo of age
includes
A. vanco and ampicillin
B. aminoglycoside and ampicillin
C. ceftriaxone and vancomycin
D. vanco and aminoglycosides
E. ampicillin and ceftriaxone ----Answers----B. the regimen
covers the most likely organisms for meningitis in this age
group: Stept agalactiae, E.coli, Listeria monocytogenes
(ampicillin), and Klebsiella species. Ampicillin and cefotaxime
would be another appropriate choice for empiric therapy in pts
up to 1mo of age
CF is a 65yo male diagnosed with endocarditis. Blood cultures
reveal a highly sensitive strain of Streptococcus. Which of the
following is most appropriate if CF has an anaphylactoid
penicillin allergy?
A. vancomycin
B. gentamicin
C. ceftriaxone and gentamicin
,D. meropenem
E. rifampin and gentamicin ----Answers----A. Vancomycin is
appropriate for penicillin allergic pts with endocarditis caused
by Strept species. Other regimens for strep include penicillin
or ceftriaxone (w/ or w/o gent), which has a potential for
cross-linking reactivity in pts w/ penicillin allergies
Pts presenting with acute bronchitis without risk factors
should be treated empirically with
A. supportive care
B. clarithromcyin
C. cefuroxime
D. ciprofloxacin
E. erythromycin ----Answers----A. B/c half of bronchitis infx
are caused by viral etiology, antibacterial therapy for low-risk
pts should not be attempted unless severe presentation
The most common organisms associated with CAP in adults
treated as outpts are
A. pseudomonas aeruginosa, mycoplasma pneumo, and h. flu
B. strept pneumo, h. flu. and klebsiella pneumo
C. mycoplasma pneumo, strept pneumo, h. flu, and kleb
pneumo
D. mycoplasma pneumo, strept pneumo, h. flu, and
chlamydophila pneumo
, E. mycoplasma pneumo, strept pneumo, h. flu, and
pseudomonas aeruginosa ----Answers----D. Pseudomonas
aeruginosa is more likely in pts with risk factors for multidrug
resistant bacteria such as late-onset HAP or VAP. Kleb
pneumoniae is also not commonly associated with CAP.
Which of the following is an appropriate regimen for a pt w/
early-onset HAP w/o risk factors for MDR pathogens?
A. doxycycline
B. azithromycin
C. unasyn
D. cipro and vanco
E. cefepime, cipro, and vanco ----Answers----C. Empiric
therapy for early-onset HAP w/o risk factors for MDR
resistant pathogens is as follows: ceftriaxone, a
fluoroquinolone, unasyn, or ertapenem. Doxycycline or
azithromycin is appropriate for outpatient treatment of CAP.
Cefepime, cipro and vanco in combination are appropriate for
late-onset HAP or pts w/ risk factors for MDR.
Initial treatment of active TB infections in which no resistant
strains of mycobacterium tuberculosis are suspected should
include
A. rifabutin and pyrazinamide
B. rifampin and pyrazinamide
C. ethambutol, rifampin, isoniazid, and pyrazinamide
VERIFIED ANSWERS
When 2 anti-infective therapies together produce a greater
effect than the effects of each used alone, this phenomenon is
termed
A. commensalism
B. synergy
C. antagonism
D. additive
E. interacting ----Answers----B. Synergy
Analysis of the cerebrospinal fluid may give valuable clues to
the identity of the pathogen in meningitis. Given the following
results, what would be indicative of a bacterial infx?
I. increased WBCs
II. increased glucose
III. increased protein
A. I only
B. II only
C. I and III only
,D. II and III only
E. all of the above ----Answers----C. Bacterial meningitis infx
show an increase in WBC and proteins in the CSF. Glucose is
decreased
Empiric therapy for meningitis for pts up to 1mo of age
includes
A. vanco and ampicillin
B. aminoglycoside and ampicillin
C. ceftriaxone and vancomycin
D. vanco and aminoglycosides
E. ampicillin and ceftriaxone ----Answers----B. the regimen
covers the most likely organisms for meningitis in this age
group: Stept agalactiae, E.coli, Listeria monocytogenes
(ampicillin), and Klebsiella species. Ampicillin and cefotaxime
would be another appropriate choice for empiric therapy in pts
up to 1mo of age
CF is a 65yo male diagnosed with endocarditis. Blood cultures
reveal a highly sensitive strain of Streptococcus. Which of the
following is most appropriate if CF has an anaphylactoid
penicillin allergy?
A. vancomycin
B. gentamicin
C. ceftriaxone and gentamicin
,D. meropenem
E. rifampin and gentamicin ----Answers----A. Vancomycin is
appropriate for penicillin allergic pts with endocarditis caused
by Strept species. Other regimens for strep include penicillin
or ceftriaxone (w/ or w/o gent), which has a potential for
cross-linking reactivity in pts w/ penicillin allergies
Pts presenting with acute bronchitis without risk factors
should be treated empirically with
A. supportive care
B. clarithromcyin
C. cefuroxime
D. ciprofloxacin
E. erythromycin ----Answers----A. B/c half of bronchitis infx
are caused by viral etiology, antibacterial therapy for low-risk
pts should not be attempted unless severe presentation
The most common organisms associated with CAP in adults
treated as outpts are
A. pseudomonas aeruginosa, mycoplasma pneumo, and h. flu
B. strept pneumo, h. flu. and klebsiella pneumo
C. mycoplasma pneumo, strept pneumo, h. flu, and kleb
pneumo
D. mycoplasma pneumo, strept pneumo, h. flu, and
chlamydophila pneumo
, E. mycoplasma pneumo, strept pneumo, h. flu, and
pseudomonas aeruginosa ----Answers----D. Pseudomonas
aeruginosa is more likely in pts with risk factors for multidrug
resistant bacteria such as late-onset HAP or VAP. Kleb
pneumoniae is also not commonly associated with CAP.
Which of the following is an appropriate regimen for a pt w/
early-onset HAP w/o risk factors for MDR pathogens?
A. doxycycline
B. azithromycin
C. unasyn
D. cipro and vanco
E. cefepime, cipro, and vanco ----Answers----C. Empiric
therapy for early-onset HAP w/o risk factors for MDR
resistant pathogens is as follows: ceftriaxone, a
fluoroquinolone, unasyn, or ertapenem. Doxycycline or
azithromycin is appropriate for outpatient treatment of CAP.
Cefepime, cipro and vanco in combination are appropriate for
late-onset HAP or pts w/ risk factors for MDR.
Initial treatment of active TB infections in which no resistant
strains of mycobacterium tuberculosis are suspected should
include
A. rifabutin and pyrazinamide
B. rifampin and pyrazinamide
C. ethambutol, rifampin, isoniazid, and pyrazinamide
