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
M
A. commensalism
ED
B. synergy
C. antagonism
D. additive
ST
E. interacting ----Answers----B. Synergy
Analysis of the cerebrospinal fluid may give valuable clues to
U
the identity of the pathogen in meningitis. Given the following
results, what would be indicative of a bacterial infx?
D
Y
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
M
B. aminoglycoside and ampicillin
ED
C. ceftriaxone and vancomycin
D. vanco and aminoglycosides
E. ampicillin and ceftriaxone ----Answers----B. the regimen
ST
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
U
therapy in pts up to 1mo of age
D
CF is a 65yo male diagnosed with endocarditis. Blood
Y
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
M
ED
A. supportive care
B. clarithromcyin
C. cefuroxime
ST
D. ciprofloxacin
E. erythromycin ----Answers----A. B/c half of bronchitis infx
are caused by viral etiology, antibacterial therapy for low-risk
U
pts should not be attempted unless severe presentation
D
The most common organisms associated with CAP in adults
Y
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?
M
A. doxycycline
ED
B. azithromycin
C. unasyn
D. cipro and vanco
ST
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
U
fluoroquinolone, unasyn, or ertapenem. Doxycycline or
azithromycin is appropriate for outpatient treatment of
D
CAP. Cefepime, cipro and vanco in combination are
appropriate for late-onset HAP or pts w/ risk factors for
Y
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
M
A. commensalism
ED
B. synergy
C. antagonism
D. additive
ST
E. interacting ----Answers----B. Synergy
Analysis of the cerebrospinal fluid may give valuable clues to
U
the identity of the pathogen in meningitis. Given the following
results, what would be indicative of a bacterial infx?
D
Y
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
M
B. aminoglycoside and ampicillin
ED
C. ceftriaxone and vancomycin
D. vanco and aminoglycosides
E. ampicillin and ceftriaxone ----Answers----B. the regimen
ST
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
U
therapy in pts up to 1mo of age
D
CF is a 65yo male diagnosed with endocarditis. Blood
Y
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
M
ED
A. supportive care
B. clarithromcyin
C. cefuroxime
ST
D. ciprofloxacin
E. erythromycin ----Answers----A. B/c half of bronchitis infx
are caused by viral etiology, antibacterial therapy for low-risk
U
pts should not be attempted unless severe presentation
D
The most common organisms associated with CAP in adults
Y
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?
M
A. doxycycline
ED
B. azithromycin
C. unasyn
D. cipro and vanco
ST
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
U
fluoroquinolone, unasyn, or ertapenem. Doxycycline or
azithromycin is appropriate for outpatient treatment of
D
CAP. Cefepime, cipro and vanco in combination are
appropriate for late-onset HAP or pts w/ risk factors for
Y
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
