ID 2 Flashcards
- K.E. is a 29-year-old asymptomatic patient who is
HIV positive. She recently found out she is pregnant
and is estimated to be early in her first trimester.
Her most recent CD4 count was 170 cells/
mm3, and her viral load was 100,000 copies/mL by
reverse transcriptase polymerase chain reaction.
Which is the best therapy for K.E. to prevent HIV
transmission to her child?
A. No drug therapy is needed; the risks to the
fetus outweigh any benefits.
B. Administer zidovudine 300 mg twice daily
orally throughout the pregnancy, followed by
zidovudine during labor and subsequently to
the infant for 6 weeks.
C. No drug therapy is needed now, but administer
a single dose of nevirapine at the onset of labor.
D. Administer a potent combination antiretroviral
therapy (ART) regimen.
- Answer: D
Transmission of HIV to a child is decreased if the mother’s
viral load is decreased. The benefits of therapy far
outweigh the risk (Answer A is incorrect). A potent
combination ART regimen given throughout the pregnancy
is the most appropriate therapeutic regimen for an
asymptomatic patient with HIV who is pregnant (even
in the first trimester) and has a low CD4 count and high
viral load (Answer D is correct). Although zidovudine
300 mg twice daily orally throughout the pregnancy, followed
by zidovudine during labor and to the child for 6
weeks, was the regimen originally studied to decrease
HIV transmission, potent combination ART is indicated
because of the patient’s low CD4 count and high viral
load; therefore, single-drug therapy is inappropriate
(Answer B is incorrect). A single dose of nevirapine at
the onset of labor will not affect viral load or lower the
risk of HIV transmission as much as potent combination
ART throughout the pregnancy (Answer C is incorrect).
- R.E. is a 33-year-old man who recently tested HIV
positive. He is initiated on tenofovir alafenamide,
emtricitabine, and dolutegravir. Which is the best
counseling for R.E.?
A. Watch for trouble sleeping because dolutegravir
can cause insomnia.
B. If you think you are having a drug-related
adverse effect, cut the dose of all of your drugs
in half.
C. Talk to your pharmacist about drug interactions
because both dolutegravir and tenofovir
inhibit cytochrome P450 (CYP) 3A4.
D. Tenofovir and emtricitabine cause additive
peripheral neuropathy, so let your pharmacist
know if you have tingling in your extremities.
- Answer: A
The patient should be told that dolutegravir can cause
insomnia (Answer A is correct). This patient should be
told to talk to a pharmacist about the current combination
therapy because there are many drug interactions
with antiretroviral agents. However, neither dolutegravir
nor tenofovir inhibit CYP3A4 (Answer C is incorrect).
Informing the patient to cut the dose in half if
there are adverse effects is incorrect because antiretroviral
drugs should never be used below the recommended
dose (Answer B is incorrect). Informing the
patient that tenofovir and emtricitabine cause additive
peripheral neuropathy is incorrect because neither
of these drugs is associated with that adverse effect
(Answer D is incorrect).
- P.P., a 43-year-old man who is HIV positive, presents
to the clinic with a headache that has gradually
worsened during the past 2 weeks. He does not
feel very sick and has not experienced any focal
seizures. His most recent CD4 count was 35 cells/
mm3. After a lumbar puncture is performed, he is
given a diagnosis of cryptococcal meningitis and
successfully treated. Which is the best follow-up
therapy for P.P.?
A. No maintenance treatment is necessary.
B. Administer fluconazole 200 mg daily orally.
C. Administer amphotericin B 1 mg/kg weekly
intravenously.
D. He is protected as long as he is also receiving
Pneumocystis jiroveci pneumonia (PJP)
prophylaxis.
- Answer: B
Patients with cryptococcal meningitis should always
receive maintenance therapy (Answer A is incorrect).
One of the principles of treating AIDS-related illnesses
is that the infections are seldom curable, and generally
long-term secondary prevention is required. Weekly
amphotericin B has been studied for secondary prophylaxis,
but fluconazole is the better agent because of its
ease of administration and lower toxicity (Answer B is
correct and answer C is incorrect). The agents that are effective for PJP prophylaxis have no activity against
Cryptococcus (Answer D is incorrect).
- A study compares the incidence of active tuberculosis
(TB) infection in patients receiving isoniazid
versus rifampin for latent TB infection. After
completing therapy (6 months for isoniazid and 4
months for rifampin), 0.3% in the isoniazid group
and 0.8% in the rifampin group progress to active
disease. Which best represents how many patients
would need to be treated with isoniazid over rifampin
to prevent one progression to active disease?
A. 5.
B. 50.
C. 200.
D. 2000.
- Answer: C
The number of patients needed to treat with isoniazid
over rifampin to prevent one progression to active disease
is 200 = 1/(0.008 − 0.003) (Answers A, B, and D
are incorrect and answer C is correct).
- G.T. is a 34-year-old woman positive for HIV who
is brought to the emergency department by her
boyfriend after experiencing headaches, a change
in mental status, and loss of feeling on her right
side. A computed tomographic scan shows two
large ring-enhancing lesions in her brain indicating
toxoplasmic encephalitis. Her most recent CD4
count was 85 cells/mm3, but that was 4 months ago.
She currently takes no antiretroviral agents but does take dapsone for PJP prophylaxis. Which is
the best therapy for G.T.?
A. Atovaquone for 4–6 weeks.
B. High-dose trimethoprim/sulfamethoxazole plus
clindamycin for 6 weeks.
C. Pyrimethamine plus sulfadiazine for 6 weeks.
D. Pyrimethamine plus clindamycin and leucovorin
for 6 weeks.
- Answer: D
Pyrimethamine plus clindamycin and leucovorin for 6
weeks is the correct choice for treating toxoplasmosis in
a patient who is HIV positive, not taking antiretrovirals,
and taking dapsone for PJP prophylaxis (Answer D is
correct). Atovaquone is not first-line therapy, although
data support its effectiveness in combination with sulfadiazine
or pyrimethamine (Answer A is incorrect);
trimethoprim/sulfamethoxazole is not effective for
treatment or secondary prophylaxis of toxoplasmosis
(Answer B is incorrect). Pyrimethamine and sulfadiazine
are the first-line agents for toxoplasmosis; however,
leucovorin should always be used with pyrimethamine
to prevent myelosuppression (Answer C is incorrect).
- H.Y., a 49-year-old man with acute myeloid leukemia,
is given a diagnosis of tuberculosis (TB) and
initiated on empiric therapy with rifampin, isoniazid,
ethambutol, and pyrazinamide. Three months
into his TB therapy, he is hospitalized and given a
diagnosis of aspergillosis; treatment is needed in
addition to his TB treatment. Which is the best antifungal
to use in H.Y.?
A. Fluconazole.
B. Voriconazole.
C. Isavuconazonium.
D. Amphotericin lipid formulation
- Answer: D
Fluconazole has no activity against aspergillus, so
it would not be an option for therapy (Answer A is
incorrect). Although voriconazole has activity against
aspergillus, there is a significant interaction with rifampin,
resulting in lower voriconazole concentrations
(Answer B is incorrect). Isavuconazonium does have
activity against aspergillus, but levels are significantly
decreased in a patient receiving rifampin (Answer C is
incorrect). Amphotericin lipid formulation would be
the best option because of its activity against aspergillus
and lack of drug interaction with any of the TB
medications (Answer D is correct).
- P.I. is a 35-year-old woman who presents to the
clinic with a 2-week history of night sweats, fatigue,
weight loss, and a persistent cough. A tuberculin
skin test (TST) is placed, and a sputum sample is
taken; then, P.I. is sent home with a prescription for
levofloxacin 750 mg daily orally. Two days later, her
TST is measured at 20-mm induration, and her sputum
sample is positive for acid-fast bacilli. P.I., who
has no pertinent medical history, has never been
outside the United States. She lives in an area with
an extremely low incidence of multidrug-resistant
TB. Which regimen is the best therapy for P.I.?
A. Isoniazid for 6 months.
B. Isoniazid, rifampin, pyrazinamide, and ethambutol
for 2 months, followed by isoniazid
and rifampin for 4 more months.
C. Isoniazid and rifampin for 6 months.
D. Levofloxacin, isoniazid, and rifampin for both
TB and other bacterial causes of pneumonia.
- Answer: B
Because the patient is symptomatic and her sputum
is acid-fast bacillus positive, she should be treated for
an active TB infection. The recommended therapy for
active TB is isoniazid, rifampin, pyrazinamide, and
ethambutol for 2 months, followed by isoniazid and
rifampin for 4 more months (Answer B is correct).
Patients should be initiated on at least three antibiotics
for the first 2 months (Answers A and C are incorrect). Although fluoroquinolones have some activity against
TB, their use as first-line monotherapy is inappropriate
(Answer D is incorrect).
- A prospective, double-blind study compared the
effects of two therapies—a potent combination
ART with a ritonavir-boosted protease inhibitor
(PI) and a potent combination ART with dolutegravir—in 350 patients with HIV. Which is
the best statistical test to use to compare end points
such as the mean change in viral load or mean
change in CD4 counts?
A. Analysis of variance.
B. Chi-square test.
C. Student t-test.
D. Wilcoxon rank sum test.
- Answer: C
Data are continuous and probably normally distributed
(given the large population of 350 patients in the study);
therefore, a parametric test is indicated. The t-test
is the best parametric test for comparing two groups
(Answer C is correct). Although an analysis of variance
is a parametric test, it is used to compare more than
two groups (Answer A is incorrect). A chi-square test
is used to compare nominal or categorical data between
two groups (Answer B is incorrect). The end points in
this study are continuous and should therefore not be
compared using this statistical test. The Wilcoxon rank
sum test is a nonparametric analog to the t-test (Answer
D is incorrect).
- J.Z. is a 42-year-old HIV-positive man with a diagnosis
of cytomegalovirus (CMV) retinitis 9 months
ago. Since then, he has been treated with valganciclovir.
When he received a diagnosis of CMV retinitis,
his CD4 count was 17 cells/mm3, and he was
initiated on combination ART. Three months ago,
his CD4 count was 175 cells/mm3. Today, his CD4
count is 312 cells/mm3. Which is the best recommendation
for valganciclovir therapy in J.Z.?
A. Discontinue valganciclovir because his CD4
count has been above 100 cells/mm3 for 3
months.
B. Continue valganciclovir until the CD4 count
has been above 100 cells/mm3 for 1 year.
C. Finish 1 year of therapy with valganciclovir
and then discontinue the medication if his
CD4 count is still above 100 cells/mm3.
D. Continue valganciclovir indefinitely.
- Answer: A
Valganciclovir therapy should be continued in an HIVpositive
patient with CMV retinitis until the patient’s
CD4 count is above 100 cells/mm3 for at least 3 months
(Answer A is correct, answers B, C and D are incorrect).
There is no minimum duration of therapy for
CMV retinitis, as there is with MAC or cryptococcal
infections. Therapy would need to be reinitiated if his
CD4 count fell back below 100 cells/mm3. In patients
with CMV retinitis, all lesions must be inactive and the
decision to stop maintenance treatment made in collaboration
with an ophthalmologist.
- K.T. is a 55-year-old woman who is hospitalized
with a presumed Candida infection. She currently
receives simvastatin, diazepam, lisinopril, dofetilide,
and metoprolol. Which azole antifungal
would be best to use to avoid interactions with the
other medications K.T. is receiving?
A. Itraconazole.
B. Fluconazole.
C. Voriconazole.
D. Isavuconazonium.
- Answer: B
All azole antifungals interact with CYP enzymes.
However, fluconazole has less CYP3A4 inhibition than
the other azole antifungals (Answer B is correct). It
interacts with CYP2C9 at lower doses, but it interacts
with CYP3A4 only at doses of 400 mg/day or higher.
All other azole antifungals interact with CYP3A4
at typical therapeutic doses (Answer A, C and D are
incorrect).
- T.E. is a 51-year-old man who has been HIV positive
for 23 years. He is hospitalized for cellulitis
and reports that he has not taken his ART for at
least a year. His current CD4 count is 112 cells/
mm3. He is allergic to penicillins and sulfonamide
antibiotics. Which regimen is the best PJP prophylaxis
for T.E.?
A. Trimethoprim/sulfamethoxazole one doublestrength
tablet by mouth daily.
B. Dapsone 100 mg by mouth weekly.
C. Atovaquone 1500 mg by mouth daily.
D. Pentamidine 300 mg by nebulization once
monthly.
Because the patient has a sulfonamide allergy, trimethoprim/
sulfamethoxazole is not an option, even
though the dose is correct (Answer A is incorrect). All
of the other agents are potential options. However, the
dapsone dose is incorrect, and dapsone should be used
with caution in patients with sulfonamide allergies.
When used alone it must be dosed daily (Answer B is
incorrect). Moreover, pentamidine is difficult to administer
because it must be done by nebulization (Answer
D is incorrect). Therefore, the best choice is atovaquone
(Answer C is correct).
- O.D. is a 38-year-old HIV positive man originally
from Puerto Rico who moved to the continental
United States four years ago. He is hospitalized
for fever, weight loss, chills, myalgia, and lymphadenopathy.
He is initially treated for PJP but his
symptoms worsen. A bronchoscopy is performed
and the cultures are positive for Histoplasma capsulatum.
What is the best treatment for O.D.?
A. Amphotericin B lipid formulation for 1-2
weeks followed by itraconazole 200 mg daily
for 12 weeks total.
B. Micafungin 100 mg IV daily for 1-2 weeks
followed by fluconazole 400 mg daily for 12
weeks total.
C. Voriconazole 200 mg twice daily for 6 weeks
total.
D. Isavuconazole 200 mg every 8 hours for 2 days
followed by 200 mg daily for 6 weeks total.
- Answer: A
Given the fact that this patient is hospitalized and his
infection is worsening, this can be considered a moderate
to severe case of Histoplasmosis. The correct regimen
is 1-2 weeks of an amphotericin B lipid formulation
followed by itraconazole to complete a 12-week course
(Answer A is correct). The echinocandins appear to be
ineffective against Histoplasma so micafungin should
not be used (answer B is incorrect). Although both
voriconazole and isavuconazole have activity against
Histoplasma they currently aren’t recommended based
on limited to no clinical data supporting their use.
Voriconazole also has significant drug interactions
(as does itraconazole) and isavuconazole is expensive
(answers C and D are incorrect).
- R.V. is a 35-year-old man who presents to the emergency
department with a persistent cough, night
sweats, and an unintentional 15 kg recent weight
loss. He has experienced homelessness for over 3
years and has been living at multiple shelters in
the city. An interferon-gamma release assay test
is positive and his sputum is acid-fast bacillus positive.
He is not HIV-infected. Which one of the following
would be the best empiric therapy for R.V.?
A. Rifampin, isoniazid, pyrazinamide, and ethambutol
3 times weekly for 2 months followed
by rifampin and isoniazid 2 times weekly for 4
months.
B. Rifampin, isoniazid, pyrazinamide, and ethambutol
daily for 2 months followed by rifampin
and isoniazid 5 times weekly for 4 months.
C. Rifampin, isoniazid, pyrazinamide, and ethambutol
daily for 2 months followed by rifampin,
isoniazid, and ethambutol 3 times weekly
for 4 months.
D. Rifampin, isoniazid, pyrazinamide, and ethambutol
5 times weekly for 2 months followed
by rifampin, isoniazid, and pyrazinamide 2
times weekly for 4 months.
- Answer: B
This patient has active tuberculosis as demonstrated
by his symptoms, positive sputum, and positive IGRA
test. Patients with active tuberculosis should be treated
with 4 drugs (rifampin, isoniazid, pyrazinamide, ethambutol)
for 2 months and 2 drugs (rifampin and isoniazid)
for 4 months (answers C and D are incorrect).
Although a regimen administered 2 and 3 times weekly
is optional, it is not the recommended therapy (answer
A is incorrect). However, in this man experiencing
homelessness, it may be necessary if he cannot adhere
to daily or five-times-weekly dosing. Ideally, active
tuberculosis treatment should be given either daily or
5 times weekly (Answer B is correct).
Patient Case
1. F.G. is a 27-year-old man who is HIV positive but asymptomatic. His CD4 count is 550 cells/mm3
, and his
viral load is 5000 copies/mL by reverse transcriptase polymerase chain reaction. Which is the best treatment
for F.G.?
A. ART should not be given because his CD4 count is still above 500 cells/mm3
.
B. Initiate emtricitabine/tenofovir only because his CD4 count is still above 500 cells/mm3
.
C. Initiate combination therapy of abacavir, lamivudine, and atazanavir/ritonavir.
D. Initiate combination therapy of tenofovir, emtricitabine, and dolutegravir.
- Answer: D
The patient should be treated at this time; a potent com-
bination ART should be initiated in all HIV-infected
patients, regardless of CD4 count (Answer A is incor-
rect). Combination therapy of tenofovir, emtricitabine,
and dolutegravir is a recommended initial therapeutic
regimen (Answer D is correct). Regimens without an
NNRTI, PI, or INSTI are not indicated for HIV (Answer
B is incorrect). The regimen of abacavir, lamivudine,
and atazanavir/ritonavir is not a recommended or alter-
native option. It should only be used if recommended
or alternative options are not appropriate (Answer C is
incorrect)
Patient Case
2. Six months after F.G. (from patient case 1) starts appropriate therapy, his CD4 count is 720 cells/mm3
, and his
viral load is undetectable. Two years later, his CD4 count decreases to 310 cells/mm3
, and his viral load is 15,000
copies/mL. Resistance testing detects resistance to dolutegravir. His HIV regimen is changed to abacavir, lami-
vudine, and darunavir/ritonavir. Which of the following tests must be performed before starting abacavir?
A. Liver function tests because of the risk of hepatotoxicity.
B. HLA-B*5701 allele screening because of the risk of a serious hypersensitivity reaction.
C. Hemoglobin A1C and a lipid panel because of the risk of endocrine disturbances.
D. Bilirubin because of the risk of hyperbilirubinemia
- Answer: B
A patient taking abacavir should be screened for the
presence of the HLA-B*5701 allele before initiating
therapy. If the patient is positive for this allele, the risk
of hypersensitivity reactions is increased (Answer B
is correct). Although abacavir may increase AST and
ALT concentrations, the incidence of hepatotoxicity is
extremely low and these labs do not need to be checked
before starting therapy. (Answer A is incorrect).
Endocrine disturbances (e.g., hyperglycemia, fat redis-
tribution, lipid abnormalities) are more associated with
PIs (Answer C is incorrect). Abacavir does not cause
hyperbilirubinemia; therefore, the patient need not be
monitored for this (Answer D is incorrect).
Patient Cases
3. Three years later, F.G. (from patient cases 1–2) has not responded to any of his ART regimens because of
resistance or intolerance. His CD4 count has decreased to 135 cells/mm3
. For which infection is it most
important that F.G. receive primary prophylaxis?
A. Pneumocystis jiroveci pneumonia (PJP).
B. Cryptococcal meningitis.
C. Cytomegalovirus (CMV).
D. Mycobacterium avium complex (MAC).
- Answer: A
When the CD4 count decreases to 135 cells/mm3
, the
patient should receive primary prophylactic treat-
ment against PJP (CD4 count less than 200 cells/mm3
)
(Answer A is correct). Primary prophylaxis is neces-
sary for MAC when the CD4 count is less than 50 cells/
mm3
(Answer D is incorrect). For CMV, patients with
CD4 counts less than 50 cells/mm3
should receive reg-
ular funduscopic examinations (Answer C is incorrect).
In general, primary prophylaxis is not used for crypto-
coccal meningitis (Answer B is incorrect).
- B.L. is a 44-year-old HIV-positive man who arrives at the emergency department severely short of breath.
He is an extremely nonadherent patient and has not seen a health care provider in more than 3 years. A chest
radiograph shows pulmonary infiltrates in both lung fields. The results of the laboratory tests are as follows:
sodium 147 mEq/L, potassium 4.2 mEq/L, chloride 104 mEq/L, bicarbonate 25.2 mEq/L, glucose 107 mg/
dL, blood urea nitrogen 38 mg/dL, serum creatinine 1.1 mg/dL, aspartate aminotransferase 28 IU/L, alanine
aminotransferase 32 IU/L, lactate dehydrogenase 386 IU/L, alkaline phosphate 75 IU/L, pH 7.45, Po2
63 mm
Hg, Pco2
32 mm Hg, and oxygen saturation 85%. His CD4 count is 98 cells/mm3
. Sputum Gram stain is neg-
ative, as is silver stain. Which is the best therapy for B.L.?
A. Pentamidine intravenously with adjuvant prednisone therapy for 21 days.
B. Trimethoprim/sulfamethoxazole orally for 21 days.
C. Trimethoprim/sulfamethoxazole intravenously with adjuvant prednisone therapy for 21 days.
D. Atovaquone orally for 21 days.
- Answer: C
Although pentamidine would be an appropriate alterna-
tive therapeutic option for a patient who is HIV positive
with PJP, the optimal empiric therapy is trimethoprim/
sulfamethoxazole intravenously with adjuvant predni-
sone therapy for 21 days (Answer A is incorrect and
answer C is correct). The regimen may be changed to
trimethoprim/sulfamethoxazole orally after the patient
has clinical improvement. Although trimethoprim/
sulfamethoxazole is the drug of choice for PJP, adjuvant
prednisone therapy is indicated because the patient’s
A-a gradient is 55, and his PO2
is less than 70 mm Hg
(Answer B is incorrect). Atovaquone is indicated only
for patients with mild to moderate PJP who cannot tol-
erate trimethoprim/sulfamethoxazole. This patient does
not meet this criterion (Answer D is incorrect).
Patient Cases
5. G.H. is a 33-year-old HIV-positive man who presents to the clinic with a severe headache that has gradually
worsened during the past 3 weeks. He also has memory problems and is always tired. He has refused ART in
the past, and his most recent CD4 count was 75 cells/mm3
. He is given a diagnosis of cryptococcal meningitis.
Which is the best treatment for G.H.?
A. Amphotericin B deoxycholate 0.7–1 mg/kg/day plus fluconazole 800 mg daily for 2 weeks, followed by
fluconazole 400 mg/day for 8 weeks. Begin ART in the first 1–2 weeks of therapy.
B. Liposomal amphotericin B 3–4 mg/kg/day plus flucytosine 25 mg/kg every 6 hours for 2 weeks, followed
by fluconazole 400 mg/day for 8 weeks. Begin ART after 5 weeks of antifungal therapy.
C. Fluconazole 1200 mg/day for 10–12 weeks. Begin ART fluconazole 800 mg daily.
D. Lipid-formulated amphotericin B 3–4 mg/kg/day plus fluconazole 800 mg/day for 2 weeks, followed by
fluconazole 400 mg/day for 8 weeks. Begin ART in the first 1-2 weeks of therapy.
- Answer: B
Patients with cryptococcal meningitis should ideally be
treated with liposomal amphotericin and flucytosine for
at least 2 weeks, followed by fluconazole for at least 8
weeks (Answer B is correct). Although amphotericin B
deoxycholate with fluconazole is an alternative, this is
not the best option (Answer A is incorrect). Fluconazole
alone is also an alternative but should only be used
when none of the amphotericin products is an option for
therapy (Answer C is incorrect). Because of the higher
mortality when ART is begun early in cryptococcal
meningitis therapy, initiation of ART should be delayed
until 5 weeks after beginning appropriate antifungal
therapy (Answer D is incorrect).
- After being treated for cryptococcal meningitis, G.H. is initiated on potent combination ART. For 2, 6, and
8 months after starting the therapy, his CD4 counts are 212, 344, and 484 cells/mm3
, respectively. Which is
the best follow-up therapy for G.H. now?
A. Continue fluconazole maintenance therapy.
B. Give maintenance therapy with fluconazole for at least 1 year; then, it can be discontinued because the
CD4 counts have increased.
C. Continue maintenance therapy with fluconazole until CD4 counts are greater than 500 cells/mm3
.
D. Discontinue maintenance therapy with fluconazole.
- Answer: B
Maintenance therapy for cryptococcal meningitis with
fluconazole can be discontinued after a minimum of 1
year of long-term maintenance therapy if the CD4 count
increases to more than 100 cells/mm3
for 3 months or
longer after potent combination ART (Answer B is cor-
rect and answer D is incorrect). Because this patient’s
CD4 counts have been greater than 100 cells/mm3
for at
least 3 months, maintenance therapy can be discontin-
ued after he has been treated for 1 year (Answers A and
C are incorrect).
Patient Case
7. J.C. is a 36-year-old HIV-positive woman with severe anemia. She has been tested for iron deficiency and
has been taken off zidovudine and trimethoprim/sulfamethoxazole. She has also started to lose weight and
to have severe diarrhea. A blood culture is positive for Mycobacterium avium-inracellulare (MAI). Which
treatment is best for J.C.?
A. Clarithromycin plus ethambutol for 2 weeks, followed by maintenance with clarithromycin alone.
B. Azithromycin plus ethambutol for at least 12 months.
C. Clarithromycin plus isoniazid for 2 weeks, followed by maintenance with clarithromycin alone.
D. Ethambutol plus rifabutin indefinitely.
- Answer: B
For the treatment of MAC, azithromycin plus ethambutol
for at least 12 months is the best therapeutic combination;
this combination includes one of the newer macrolides
and a second agent (ethambutol is usually the preferred
second agent) (Answer B is correct). Therapy may be dis-
continued after 12 months if CD4 counts increase with
potent combination ART and if the patient is asymp-
tomatic. Clarithromycin plus ethambutol for 2 weeks, followed by maintenance with clarithromycin alone, is
incorrect because there is no induction period for MAC
(Answer A is incorrect). A therapeutic regimen of clari-
thromycin plus isoniazid is inappropriate because isonia-
zid has no activity against MAC (Answer C is incorrect).
Although ethambutol plus rifabutin has activity against
MAC, current guidelines recommend regimens include
either azithromycin or clarithromycin; therefore, the eth-
ambutol plus rifabutin regimen is not the treatment of
choice (Answer D is incorrect).
Patient Case
8. J.M. is a 42-year-old man who works at a long-term care facility and was recently exposed to a patient with
TB; he was not wearing personal protective equipment. A TST is placed, and 48 hours later, he has an 18-mm
induration. This is the first time he has reacted to this test. His chest radiograph is negative. Which is best in
view of J.M.’s positive TST?
A. No treatment is necessary, and J.M. should have another TST in 8–10 weeks.
B. J.M. should have another TST in 1 week to see whether this is a booster effect.
C. J.M. should be monitored closely, but no treatment is necessary because he is older than 35 years.
D. J.M. should be initiated on rifampin 600 mg/day plus isoniazid 300 mg/day for 3 months.
- Answer: D
A patient with an induration greater than 15 mm after a
TST for TB needs to be assessed for treatment. Because
this patient works at a high-risk congregate setting (i.e.,
the long-term care facility), he needs to be treated for
latent TB (Answer A is incorrect). The booster effect
is a phenomenon associated with an initial small reac-
tion causing immunologic stimulation, followed by a
larger reaction with a subsequent test. This patient had
an initial large reaction (18-mm induration) (Answer B
is incorrect). Age is not a factor to consider in treating
latent TB (Answer C is incorrect). Initiating rifampin
plus isoniazid for a short 3-month course is the best rec-
ommendation for managing this patient’s positive TST
(Answer D is correct).
Patient Case
9. R.J. is a 32-year-old HIV-positive man who presents to the clinic with increased weight loss, night sweats,
and a cough productive of sputum. He is currently receiving darunavir/ritonavir 800 mg/100 mg daily,
tenofovir disoproxil fumarate 300 mg daily, emtricitabine 200 mg daily, fluconazole 200 mg/day orally, and
trimethoprim/sulfamethoxazole double strength daily. A sputum sample is positive for acid-fast bacillus. R.J.
lives in an area with a low incidence of multidrug-resistant TB. Which is the best initial treatment?
A. Initiate isoniazid, rifampin, and pyrazinamide with no change in HIV medications.
B. Initiate isoniazid, rifampin, and pyrazinamide; increase the dosage of darunavir/ritonavir; and use a
higher dosage of rifampin.
C. Initiate isoniazid, rifabutin, pyrazinamide, and ethambutol, with a lower dosage of rifabutin.
D. Initiate isoniazid, rifabutin, pyrazinamide, and ethambutol, and decrease the dosage of darunavir/
ritonavir.
- Answer: C
Rifampin should not be administered concurrently with
protease inhibitors (rifampin will induce the metabo-
lism of darunavir and ritonavir) (Answer A is incor-
rect). Patients who are HIV positive should be initiated
on four drugs for TB, and darunavir should not be
used with rifampin, even at a higher dose (Answer B
is incorrect). The best recommendation is isoniazid,
rifabutin, pyrazinamide, and ethambutol, with a lower
dose of rifabutin; it includes the four drugs for TB and a
lower dose of rifabutin (because of darunavir/ritonavir
inhibition) (Answer C is correct). The darunavir/
ritonavir dose does not need to be changed when rifab-
utin is added (Answer D is incorrect).
Patient Cases
10. Which represents the best follow-up for R.J. (from Patient Case 9)?
A. Treatment with the initial drugs should continue for 6 months.
B. Treatment can be decreased to isoniazid and a rifamycin after 2 months for a total treatment of 18–24
months.
C. Treatment can be decreased to isoniazid and a rifamycin after 2 months for a total treatment of 6 months;
HIV RNA concentrations should be observed closely during therapy.
D. Treatment can be decreased to isoniazid, a rifamycin, and either pyrazinamide or ethambutol after 2 months
for a total treatment of 6 months; HIV RNA concentrations should be observed closely during therapy.
- Answer: C
For this patient, only the rifamycin and isoniazid need
to be continued after 2 months of therapy with the
four drugs for TB (Answer A is incorrect). The regi-
men can be simplified to a rifamycin and isoniazid
after 2 months, but the recommended total treatment
duration is 6 months (Answers B and D are incorrect).
The concentrations of HIV RNA should be monitored
closely because of potential alterations in drug concen-
trations of the PI (Answer C is correct).
- L.F. is a 55-year-old man (73 kg) who was involved in a motor vehicle accident with subsequent rib fractures
and bilateral pneumothoraces. He is admitted to the ICU and mechanically ventilated. He is started on levo-
floxacin which after 3 days is switched to piperacillin/tazobactam and vancomycin. After 5 days of broad
spectrum antibiotics his temperature continues to spike. A blood culture is positive for Candida krusei. What
is the best treatment for L.F.?
A. Fluconazole 400 mg IV daily for 7 days following the first negative blood culture.
B. Micafungin 100 mg IV daily for 14 days following the first negative blood culture.
C. Amphotericin B lipid formulation 3 mg/kg/day for 14 days following the first negative blood culture.
D. Voriconazole 200 mg IV twice daily for 7 days following the first negative blood culture.
- Answer: B
Candida krusei is an organism that is frequently resis-
tant to azole antifungals, including fluconazole and
voriconazole; therefore, those agents should not be
used in this situation (answers A and D are incorrect).
The best choice would be either an echincocandin or
amphotericin product (although the newer azoles,
posaconazole, and isavuconazole do have some activity
against C. krusei). Given its lower side effect profile
and lack of adjustments needed for renal or hepatic dys-
function, micafungin is the best choice in this situation
(answer B is correct). The length of therapy is also cor-
rect, treatment for 14 days after the first negative blood
culture. Although an amphotericin B lipid formulation
would be a second-line option, the higher incidence of
side effects associated with its use make it not the best
choice (answer C is incorrect).
Patient Case
12. A.B. is a 55-year-old woman who presents to your clinic with toenail discoloration with a few of her toenails
separating from the nail bed. She is diagnosed with onychomycosis. What is the best treatment for A.B.?
A. Fluconazole 200 mg orally daily for 14 days.
B. Itraconazole 200 mg orally daily for 28 days.
C. Miconazole cream applied twice daily to toenails for 2 months.
D. Terbinafine 250 mg orally daily for 3 months.
- Answer: D
Onychomycosis needs to be treated for a long period
of time, generally 3 months. Although fluconazole is
active against the organisms that cause onychomycosis
and systemic therapy is generally best, a 14-day course
would not be long enough to effectively treat the infec-
tion (answer A is incorrect). Itraconazole is one of the
drugs of choice for onychomycosis, in either a continu-
ous or pulse therapeutic regimen. However, once again,
28 days is not long enough for treatment (answer B is
incorrect). There are a number of different topical anti-
fungal medications that can be used for onychomyco-
sis. However, miconazole cream is not one of them.
Also, topical treatment requires longer therapy than
systemic treatment (answer C is incorrect). Terbinafine
is one of the drugs of choice for onychomycosis and the
treatment duration, 3 months, is correct (answer D is
correct).
Patient Case
13. C.A. is a 66-year-old man with a history of advanced non–small cell lung cancer. After his most recent
chemotherapy, he became severely neutropenic and received a diagnosis of Aspergillus pneumonia. C.A. has
acute renal failure related to his chemotherapy and is receiving warfarin, diltiazem, dronedarone, atorvasta-
tin, pantoprazole, and carbamazepine. Which antifungal would be the best therapy for C.A.?
A. Lipid amphotericin.
B. Micafungin.
C. Fluconazole.
D. Voriconazole.
- Answer: B
Micafungin has activity against Aspergillus and is the
best option for this patient because it does not require
dosage adjustment for renal dysfunction and has lim-
ited drug interactions (Answer B is correct). Lipid
amphotericin has activity against Aspergillus and could
be used for this infection, but because of its renal tox-
icity, lipid amphotericin is not the best choice in this patient with acute renal failure (Answer A is incor-
rect). Fluconazole has no activity against Aspergillus
and could potentially interact with the some of the
drugs the patient is receiving (Answer C is incorrect).
Voriconazole has activity against Aspergillus, but it sig-
nificantly interacts with several of the drugs the patient
is receiving (atorvastatin, dronedarone, warfarin, car-
bamazepine), making it a less than ideal choice in this
patient (Answer D is incorrect).
