PHARM CASES 8&9

Question 1

An investigational antibiotic RY0120 if found to have bactericidal effect during pre-clinical trial studies. Which of the following antibiotics has the same mechanism of action?

A. Metronidazole
B. Chloramphenicol
C. Erythromycin
D. Clindamycin
E. Trimethoprim

Answer 1

Metronidazole

Question 2

Some important considerations when prescribing antimicrobial therapy include obtaining an accurate diagnosis of infection, identifying opportunities to switch to narrow-spectrum, cost-effectiveness and assessment of the shortest duration necessary, understanding pharmacodynamics characteristics that are peculiar to antimicrobial agents, accounting for host characteristics that influence antimicrobial activity and recognizing the adverse effects of antimicrobial agents on the host. Which of the following situations is least likely to require the use of broad spectrum antibiotic?

A. Empirically therapy for potentially serious infections
B. Treatment for drug resistant bacteria that do not respond to narrow-spectrum antibiotics
C. Microorganism infection therapy that requires post-antibiotic effect
D. Case of superinfection where multiple types of bacteria are involved
E. Prophylaxis in order to prevent bacterial infections

Answer 2

Microorganism infection therapy that requires post-antibiotic effect

Question 3

Imipenem is a β-lactam antibiotic and the first member of the carbapenem class of antibiotics. Carbapenems are resistant to the β-lactamase enzymes produced by many multiple drug-resistant Gram-negative bacteria, thus they play a key role in the treatment of infections not readily treated with other antibiotics. The emergence of imipenem-resistant Pseudomonas aeruginosa is mediated by:

A. Increased antibiotic efflux pump
B. Bypass of antibiotic inhibition
C. Enzymatic inactivation of imipenem
D. Target alteration
E. Decreased cell wall permeability

Answer 3

Decreased cell wall permeability

Question 4

A 28 years old female patient presents to your office with complaints of mild vaginal mucopurulent discharge and severe pelvic pain. She was later diagnosed with Neisseria gonorrhea infection. You prescribe a third generation cephalosporin shown to be effective in the treatment of gonorrhea.

Q1: Which of the following antibiotic was most likely prescribed?

A. Cephalexin
B. Ceftriaxone
C. Cefazolin
D. Cefuroxime
E. Cefaclor

Answer 4

Ceftriaxone

Question 5

A 28 years old female patient presents to your office with complaints of mild vaginal mucopurulent discharge and severe pelvic pain. She was later diagnosed with Neisseria gonorrhea infection. You prescribe a third generation cephalosporin shown to be effective in the treatment of gonorrhea.Q2: Which of the following drugs can be added to the previously prescribed antibiotic to effectively treat Multidrug-Resistant Neisseria gonorrhoeae?

A. Linezolid
B. Doxycycline
C. Streptomycin
D. Clindamycin
E. Amikacin

Answer 5

Doxycycline

Question 6

Methicillin-resistant Staphylococcus aureus, or MRSA has evolved into a serious public health concern. MRSA is largely a hospital-acquired infection (nosocomial). Which of the following pairs of interventions represents the preferred option for the treatment of mild to severe MRSA infections?

A. Draining skin abscesses – Doxycycline
B. Draining skin abscesses – Penicillin
C. Draining skin abscesses – Tetracycline
D. Draining skin abscesses – Vancomycin
E. Draining skin abscesses – Cefaclor

Answer 6

Draining skin abscesses – Vancomycin

Question 7

A 43-year-old woman arrived in the emergency department late at night. The patient had complained of headache throughout the day but did complete her work schedule as a store manager. She felt ill later and went to bed early complaining of headache. She awakened in the late night and seemed confused and not clearly recognizing her partner. She was transported immediately to the emergency department by her partner. With the fever and altered mental status, the possibility of a CNS infection was considered. CSF sampling confirms the diagnosis of staphylococcal meningitis. Which of the following antimicrobial agents would be the MOST appropriate for initial systemic treatment of staphylococcal meningitis?

A. Cefazolin
B. Cephalexin
C. Cefoxitin
D. Cefuroxime
E. Ceftazidime

Answer 7

Ceftazidime

Question 8

ß-lactams belong to the class of antibiotics which is characterized by a ß-lactam ring. Penicillins, cephalosporins and carbapenems are members of this family. The integrity of the ß-lactam ring is necessary for the antimicrobial activity. Resistance to ß-lactams in clinical isolates is primarily due to the hydrolysis of the antibiotic by a ß-lactamase.Which of the following antibiotics is resistant to degradation by staphylococcal penicillinase?

A. Oxacillin
B. Penicillin V
C. Amoxicillin
D. Ticarcillin
E. Penicillin G

Answer 8

Oxacillin

Question 9

Pseudomonas aeruginosa has become an important cause of infection, especially in patients with compromised immune system. It is the most common pathogen isolated from patients who have been hospitalized longer than 1 week, and it is a frequent cause of nosocomial infections. Which of the following therapeutic options could be effective against Pseudomonas aeruginosa?

A. Ampicillin - Clavulinic Acid
B. Penicillin V - Clavulinic Acid
C. Amoxicillin - Clavulinic Acid
D. Piperacillin  - Clavulinic Acid
E. Nafcillin - Clavulinic Acid

Answer 9

Piperacillin - Clavulinic Acid

Question 10

A 24-year old woman with no previous history of UTI, complains of burning on urination, frequent urination of a small amount, and bladder pain. A clean-catch midstream urine sample shows Gram-negative rods on Gram stain. A culture test is ordered. A diagnosis of cystitis was made based on laboratory findings. An antibiotic was prescribed. Few days later, she develops fatigue and hemolytic anemia. Which of the following drugs has most likely been prescribed?

A. Azithromycin
B. Nitrofurantoin
C. Amoxicillin
D. Doxycycline
E. Cefuroxime

Answer 10

Nitrofurantoin

Question 11

A superinfection is described as a new infection occurring in a patient having a preexisting infection. This new infection superimposed on an earlier one, especially by a different microbial agent of exogenous or endogenous origin that is resistant to the treatment used against the first infection. The administration of which of the following beta lactam antibiotics is the LEAST likely to lead to “superinfections”?

A. Oxacillin
B. Cefipime
C. Amoxicillin
D. Cefpirome
E. Ticarcillin

Answer 11

Oxacillin

Question 12

A 30 years old female presents to the Emergency Department with chills, malaise and high fever. Gram stain of blood sample reveals the presence of gram-positive bacilli.

Q1: Which of the following antibiotics would be a better therapeutic option due to enhanced gram-positive effect?

A. Nalidixic acid
B. Levofloxacin
C. Ofloxacin
D. Moxifloxacin
E. Norfloxacin

Answer 12

Moxifloxacin

Question 13

Q2: Which of the following statements best describes the mechanism of the drug in question 1?

A. Inhibits the enzyme transpeptidase preventing the cross-linking of D-alanine to L-glycine
B. Bind and block Topoisomerase II and topoisomerase IV
C. Inhibits protein synthesis by binding to 50S subunit
D. Prevents the last step in peptidoglycan synthesis
E. Inhibits protein synthesis by binding to 30S subunit

Answer 13

Bind and block Topoisomerase II and topoisomerase IV

Question 14

Q3: Which of the following pairs of side effects are associated with the drug in question 1?

A. Metallic taste - Megaloblastic anemia
B. Achilles tendon rupture - Long QT syndrome
C. Long QT syndrome – Metallic taste
D. Achilles tendon rupture – Ototoxicity
E. Ototoxicity – Long QT syndrome

Answer 14

Achilles tendon rupture - Long QT

Question 15

A 55 years old patient needs antibiotic for the treatment of culture positive infective enterococcal endocarditis. Enterococci are Gram-positive cocci. His medical history shows a severe reaction to penicillin G during the past year.

Q1: Which of the following antibiotics would be an appropriate therapeutic option?

A. Ampicillin
B. Amoxicillin
C. Linezolid
D. Carbecillin
E. Tazobactam

Answer 15

Linezolid

Question 16

A 55 years old patient needs antibiotic for the treatment of culture positive infective enterococcal endocarditis. Enterococci are Gram-positive cocci. His medical history shows a severe reaction to penicillin G during the past year.Q2: All of the following statements concerning the drug in question 1 are correct, EXCEPT:

A. Binds to site on the 50S subunit and prevents attachment of the 30S subunit
B. Effective against Gram positive organisms
C. Bactericidal activity is via inhibition of the formation of the ribosomal complex
D. Used to treat MRSA, VRE and drug-resistant pneumococci
E. Does not display cross-resistance with other antimicrobials

Answer 16

Bactericidal activity is via inhibition of the formation of the ribosomal complex

Question 17

Combination therapy involves the drug repurposing and regrouping of the existing antimicrobial agents to provide a synergistic approach for management of infectious diseases due to limited therapeutic options for many emerging infections. Which of the following combinations of agents is the LEAST likely to produce synergistic effects?

A. Penicillin G + tetracycline
B. Trimethoprim + sulfamethoxazole
C. Piperacillin + gentamicin
D. Cilastatin + imipenem
E. Amoxicillin + clavulanic acid

Answer 17

Penicillin G + tetracycline

Question 18

A 27-year-old female presents to the clinic with a chief complaint of burning sensation on the tongue and cheeks, and alteration of taste from the past five days. She is on inhaled fluticasone for the control of moderate asthma. Physical exam reveals white patches on the tongue and mucous membranes of the cheeks. Oral Candida infection is suspected. A culture test (scraping) confirms the diagnosis. An oral suspension administered by “swish and swallow” is prescribed. Which of the following drugs was prescribed?

A. Nystatin
B. Tolnaftate
C. Rifampin
D. Griseofulvin
E. Ketoconazole

Answer 18

Nystatin

Question 19

A 27-year-old female presents to the clinic with a chief complaint of burning sensation on the tongue and cheeks, and alteration of taste from the past five days. She is on inhaled fluticasone for the control of moderate asthma. Physical exam reveals white patches on the tongue and mucous membranes of the cheeks. Oral Candida infection is suspected. A culture test (scraping) confirms the diagnosis. An oral suspension administered by “swish and swallow” is prescribed. Q2: Which of the following statements best describes the mechanism of the drug in question 1?

A. Disrupts plasma membrane permeability by interacting with ergosterol forming artificial pores and allowing leakage of intracellular contents
B. Blocks the synthesis nucleic acids building blocks due to the inhibition of thymidine synthetase
C. Inhibits conversion of lanosterol to ergosterol a major component of fungal cell membranes
D. Interferes with fungal cell wall synthesis by blocking the synthesis of β-(1,3)-D-glucan
E. Inhibits squalene epoxidase and blocks ergosterol synthesis

Answer 19

Disrupts plasma membrane permeability by interacting with ergosterol forming artificial pores and allowing leakage of intracellular contents

Question 20

Community-acquired pneumonia (CAP) is one of the most common infectious diseases and is an important cause of mortality and morbidity worldwide. Typical bacterial pathogens that cause the condition include Streptococcus pneumoniae, Haemophilus influenza, and Moraxella catarrhalis. Which of the following antibiotics is recommended for the treatment of CAP?

A.    Loracarbef
B.    Gentamycin
C.    Chloramphenicol
D.    Azithromycin
E.    Ticarcillin

Answer 20

Azithromycin

Question 21

The patient was a 40-year-old male admitted for chronic cough and a 2-month history of intermittent afternoon fever. He denied both a history of traveling and contact with animals over the previous 3 months. Associated symptoms included general malaise, anorexia, and the loss of 6 kg body weight within the previous 2 months. A diagnosis of endocarditis was made according to Duke Criteria including two blood culture results of B. vesicularis, the presence of vegetation on the mitral valve revealed by an echocardiogram, clinical and laboratory features such as fever, splenomegaly and heart murmur. Ceftriaxone was prescribed.
Q1. Which of the following antibiotics has synergistic effect with bactericidal cell wall inhibitors?

A. Amikacin
B. Cefpirome
C. Ampicillin
D. Sulfamethoxazole
E. Norfloxacin

Answer 21

Amikacin

Question 22

Q2. Which of the following side effects could be potentially dose-limiting for the drug in question 1?

A. Bone marrow toxicity
B. Cardiotoxicity
C. Ototoxicity
D. Stevens Johnson Syndrome
E. Pseudomembranous colitis

Answer 22

Ototoxicity

Question 23

Q3. In pregnancy the drug in question 1 belongs to:

A. Class A
B. Class B
C. Class C
D. Class D
E. Class X

Answer 23

Class D

Question 24

A 5-year-old boy is brought to the pediatrician with complaints of itching around the anus; as result, he has become restless and is having difficulty sleeping. No medical history was available at the time of the visit. The doctor ordered a blood exam and pinworm paddle test. No parasites were reported from blood films. The most reliable method for diagnosing pinworm infection is the use of pinworm paddle; they are small spatulas with adhesive material on one side. The sticky side is applied to the perianal region of the patient early in the morning before bathing or defecating. The spatula is examined, adhesive side up, microscopically for eggs. The findings were consistent with pinworm eggs: 50 to 60 micrometers in length by 20 to 30 micrometers wide (figure below). A diagnosis of enterobiasis caused by pinworm is made.Which of the following drugs are recommended for the treatment of enterobiasis?

A. Praziquantel, Niclosamide
B. Albendazole, Mebendazole
C. Praziquantel, Albendazole
D. Pyrantel pamoate, Niclosamide
E. Mebendazole, Pyrantel pamoate

Answer 24

Mebendazole, Pyrantel pamoate

Question 25

A 20 year old, sexually active female presents with a one week history of a moderate vaginal discharge that has a “fishy” odor, most notable after intercourse. She has no complaints of vaginal pruritus or burning. On examination, the discharge appears gray, homogeneous, and is notably malodorous. A diagnosis of bacterial vaginosis is made. Metronidazole is prescribed. Which of the following statements is the least accurate description of metronidazole?

A. Effective in the treatment of protozoal infections
B. Reduced to nitroso intermediates by reacting with ferredoxin
C. Effective in the treatment of pseudomembranous colitis
D. Lacks luminal activity in the treatment of amebiasis
E. Induces metallic taste and Disulfiram-like reaction

Answer 25

Lacks luminal activity in the treatment of amebiasis

Question 26

VT is a 25-year-old who presents to your office with a 4-day history of abdominal cramps, and 8-10 episodes per day of watery diarrhea. She has had a few episodes of vomiting but denies fever or bloody diarrhea. She has no complaints of dysuria or back pain. She has no relevant medical history. She denies recent travel. A stool test is ordered. The results show the presence of E. coli bacteria as shown on the figure below. Which of the following intervention would be appropriate?

A. Prescribe a third generation cephalosporin
B. Prescribe a narrow spectrum penicillin
C. Prescribe an antibiotic effective against MRSA
D. Recommend loperamide and follow-up within seven days
E. Recommend rest, fluid to prevent dehydration and
follow-up within seven days

Answer 26

Recommend rest, fluid to prevent dehydration and

follow-up within seven days

Question 27

44 year old male presents to the emergency room with fever (40ºC) and general malaise of one week duration, and watery stools since the last three days. Medical and surgical history irrelevant. He denies alcohol or smoking habits, illicit drug use or sexual risk contacts. He had returned from a trip to Guatemala two weeks ago. A blood test reveals positive thick smear for Plasmodium falciparum with 37 % of parasitemia (refer to figure below).Q1. Which of the following therapeutic agents could effectively treat gametocytic and exoerythrocytic forms of the parasite?

A. Artemisinin
B. Chloroquine
C. Mefloquine
D. Primaquine
E. Pyrimethamine

Answer 27

Primaquine

Question 28

44 year old male presents to the emergency room with fever (40ºC) and general malaise of one week duration, and watery stools since the last three days. Medical and surgical history irrelevant. He denies alcohol or smoking habits, illicit drug use or sexual risk contacts. He had returned from a trip to Guatemala two weeks ago. A blood test reveals positive thick smear for Plasmodium falciparum with 37 % of parasitemia (refer to figure belowQ2. You prescribe an agent known to prevents the polymerization of heme to non-toxic hemozoin leading to the disruption of the parasite membrane. Which of the following malaria drugs has been prescribed?

A. Artemisinin
B. Chloroquine
C. Fansidar
D. Primaquine
E. Pyrimethamine

Answer 28

Chloroquine

Question 29

A 34-year-old male presents with persistent cough for more than three weeks, hemoptysis, and weight loss.He arrived recently to the US from Mexico. A sputum sample shows a positive acid-fast stain. A tuberculin test (Mantoux test) is ordered to confirm a diagnosis of tuberculosis (TB).

Q1: What is the minimum induration diameter for a positive diagnosis of TB in this patient?1 mm
A. 5 mm
B. 10 mm
C. 15 mm
D. 20 mm

Answer 29

10 mm

Question 30

A 34-year-old male presents with persistent cough for more than three weeks, hemoptysis, and weight loss.He arrived recently to the US from Mexico. A sputum sample shows a positive acid-fast stain. A tuberculin test (Mantoux test) is ordered to confirm a diagnosis of tuberculosis (TB). : Which of the following drug combinations would be an appropriate initial treatment?

A. Isoniazid
B. Isoniazid – Rifampicin
C. Isoniazid – Rifampicin – Pyrazinamide
D. Isoniazid – Rifampicin – Pyrazinamide-Ethambutol
E. Isoniazid – Rifampicin – Pyrazinamide – Dapsone

Answer 30

Isoniazid – Rifampicin – Pyrazinamide-Ethambutol

Question 31

A 34-year-old male presents with persistent cough for more than three weeks, hemoptysis, and weight loss.He arrived recently to the US from Mexico. A sputum sample shows a positive acid-fast stain. A tuberculin test (Mantoux test) is ordered to confirm a diagnosis of tuberculosis (TB). Q3: Which of the drugs in question 2 is associated with optic nerve neuritis and red-green color blindness?

A. Isoniazid
B. Rifampicin
C. Pyrazinamide
D. Ethambutol
E. Dapsone

Answer 31

Ethambutol

Question 32

A 34-year-old male presents with persistent cough for more than three weeks, hemoptysis, and weight loss.He arrived recently to the US from Mexico. A sputum sample shows a positive acid-fast stain. A tuberculin test (Mantoux test) is ordered to confirm a diagnosis of tuberculosis (TB). Q4: Which of the drugs in question 2 is associated with orange colored body fluids?

A. Isoniazid
B. Rifampicin
C. Pyrazinamide
D. Ethambutol
E. Dapsone

Answer 32

Rifampicin

Question 33

A 34-year-old male presents with persistent cough for more than three weeks, hemoptysis, and weight loss.He arrived recently to the US from Mexico. A sputum sample shows a positive acid-fast stain. A tuberculin test (Mantoux test) is ordered to confirm a diagnosis of tuberculosis (TB). Q5: You warned the patient about the incidence of peripheral neuropathy associated with isoniazid. This side effect could be managed by the administration of:

A. Ascorbic acid
B. Leucovorin
C. Pyridoxine
D. Sodium bicarbonate
E. Mesna

Answer 33

Pyridoxine

Question 34

A 31 year-old female presents to the Emergency Room with dyspnea, myalgia, and rhinorrhea. Her symptoms began approximately 24 hours ago and are continuous, steadily getting worse. She is having significant nasal discharge but minimal cough. Her 5 year-old daughter has experienced rhinorrhea as well over the past 4 days. She has no significant past medical history and takes no medications.Physical exam shows fever, lethargy, nasal discharge, shortness of breath, and muscle soreness. The rapid flu nasal swab test was positive for influenza A. Which of the following antiviral drugs would be selective for influenza A?

A. Oseltamavir
B. Acyclovir
C. Rimantadine
D. Zanamivir
E. Ganciclovir

Answer 34

Rimantadine

Question 35

Which of the sites (A, B,C, D or E) on the figure below represents the site of the action of the drug in question 1?

Answer 35

E

Question 36

A 28-year-old woman visits the clinic for evaluation. Six weeks previously, she presented with dysuria and was treated for urinary tract infection; however, symptoms persisted. She also noticed acute onset of bilateral vulval blisters. You order a HSV gG-based serology test. Serological tests for herpes simplex virus (HSV) can accurately distinguish between HSV-1 and HSV-2 by detecting antibodies to HSV glycoproteins G-1 or G-2. The test is positive for HSV-2. You initiate treatment with parenteral acyclovir.

Q1: Which of the following statements is least likely to be accurate concerning the antiviral acyclovir?

A. Guanine nucleoside analog that acts as DNA chain terminator
B. Resistance is mediated by under expression of thymidine kinase (TK)
C. Monophosphorylated by viral thymidine kinase (TK) then further bioactivated by host cell kinases to triphosphate
D. Acyclovir-triphosphate is a substrate and inhibitor of DNA polymerase
D. Used primarily for the treatment of cold sores due to herpes simplex virus type 2 infection

Answer 36

Used primarily for the treatment of cold sores due to herpes simplex virus type 2 infection

Question 37

A 28-year-old woman visits the clinic for evaluation. Six weeks previously, she presented with dysuria and was treated for urinary tract infection; however, symptoms persisted. She also noticed acute onset of bilateral vulval blisters. You order a HSV gG-based serology test. Serological tests for herpes simplex virus (HSV) can accurately distinguish between HSV-1 and HSV-2 by detecting antibodies to HSV glycoproteins G-1 or G-2. The test is positive for HSV-2. You initiate treatment with parenteral acyclovir.Few hours following the administration of parenteral acyclovir she complains of cloudy urine and mild dysuria. Microscopic urinalysis analysis reveals birefringent needle-shaped crystals (refer to figure). This side effect could be managed by increasing:

A.Physical activity
B. Carbohydrates intake
C. Fluid intake
D. Salt intake
E. Fiber intake

Answer 37

Fluid intake

Question 38

A 43-year-old HIV-infected woman with a CD4 count of 22 cells/mm3 presents with new visual problems. She describes difficulty seeing out of her left eye and she has noticed many floaters in the same eye. On examination, she has obvious decreased visual acuity in her left eye. She is urgently referred to an ophthalmologist for evaluation and cytomegalovirus (CMV) retinitis was confirmed.

Q1: Which of the following antisense therapeutic agents is effective in the treatment of CMV infection?

A. Foscarnet
B. Ganciclovir
C. Formivirsen
D. Cidofovir
E. Famciflovir

Answer 38

Formivirsen

Question 39

A 43-year-old HIV-infected woman with a CD4 count of 22 cells/mm3 presents with new visual problems. She describes difficulty seeing out of her left eye and she has noticed many floaters in the same eye. On examination, she has obvious decreased visual acuity in her left eye. She is urgently referred to an ophthalmologist for evaluation and cytomegalovirus (CMV) retinitis was confirmed. Q2: Which of the following pairs of side effects is associated with the drug in question 1?

A. Urticaria – Hallucinations
B. Myelosuppression – Nephrotoxicity
C. Cataracts – Increased IOP
D. Nephrotoxicity – Seizures
E. Arrhythmias – Increase IOP

Answer 39

Cataracts – Increased IOP

Question 40

A 41-year-old HIV-infected woman has recently been diagnosed with HIV infection. She comes to the clinic for further evaluation. She believes she was likely infected with HIV approximately 3 years ago. She complains of recurrent pneumonia. Her physical examination shows oral candidiasis. She does not have any other HIV-related manifestations and she has no history of HIV-related complications. Her CD4 count is 238 cells/mm3 (12%). Which of the following would be an appropriate conclusion?

A. She is in an advanced stage of HIV infection
B. She is in a clinical latency phase
C. She is in a terminal clinical latency phase
D. She is slowly progressing from HIV infection to AIDS
E. She has AIDS

Answer 40

She has AIDS

Question 41

Which of the following antiviral drugs is a potent inhibitor of cytochrome P450 enzymes CYP3A4 and CYP2D6 and used in low doses to “boost” the effectiveness of HIV drugs?

A. Indinavir
B. Ritonavir
C. Abacavir
D. Tenovofir
E. Saquinavir

Answer 41

Ritonavir

Question 42

A 29-year-old woman is diagnosed with asymptomatic HIV in pregnancy. Her initial laboratory studies show a CD4 count of 482 cells/mm3and an HIV RNA level of 53,638 copies/ml.Based on her last menstrual period, she is 11 weeks pregnant. She is feeling well with minimal nausea. Which of the following therapeutic regimens would help prevent vertical transmission for up to 80%?

A. ZDV full dose, trimester 1 & 2 plus 6 weeks to neonate
B. Nevirapine one dose at onset of delivery plus one dose to neonate reduce
C. Nevirapine one dose at onset of delivery plus two doses to neonate
D. ZDV full dose, trimester 2 & 3 plus 6 weeks to neonate
E. Nevirapine two doses at onset of delivery plus one dose to neonate

Answer 42

ZDV full dose, trimester 2 & 3 plus 6 weeks to neonate

Question 43

A 28-year-old HIV-infected man returns to the clinicfor a follow-up appointment to discuss whether he should start antiretroviral therapy. He was diagnosed with HIV infection about 9 months ago. His laboratory studies obtained 1, 4 and 7 months prior showed CD4 counts of 524, 608 and 692 cells/mm3. He has no HIV-related symptoms and has not had any AIDS-defining illnesses. A blood test for HLA-B5701 is positive. The patient is very interested in taking antiretroviral therapy and there are no concerns with his ability to adhere with therapy. Which of the following drug combinations would be the least appropriate therapeutic regimen in this patient?

A. EFV/TDF/FTC 
B. ATV/r plus TDF/FTC 
C. DRV/r plus TDF/FTC 
D. DTG plus ABC/3TC
E. DTG plus TDF/FTC

Answer 43

DTG plus ABC/3TC

Question 44

A 28-year-old HIV-infected man returns to the clinicfor a follow-up appointment to discuss whether he should start antiretroviral therapy. He was diagnosed with HIV infection about 9 months ago. His laboratory studies obtained 1, 4 and 7 months prior showed CD4 counts of 524, 608 and 692 cells/mm3. He has no HIV-related symptoms and has not had any AIDS-defining illnesses. A blood test for HLA-B5701 is positive. The patient is very interested in taking antiretroviral therapy and there are no concerns with his ability to adhere with therapy. Which of the following drug combinations would be the least appropriate therapeutic regimen in this patient?Q2: Cobicistat is a pharmacokinetic enhancer used to enhance the bioavailability of antiretroviral drugs metabolized by these enzymes. It is an inhibitor of cytochrome P450 3A (CYP3A) enzymes. The likelihood of icterus associated with cobicistat is enhanced by the concomitant administration of:

A. Elvitegravir 
B. Tenofovir 
C. Emtricitabine 
D. Atazanavir
E. Darunavir

Answer 44

Atazanavir

Question 45

A 62-year-old patient was admitted for unremitting, severe, right frontal headache, gait ataxia, and slurred speech for the preceding five days. His past medical history was notable for insulin-dependent diabetes, hypertension, and mitral valve replacement. The patient’s wife denied recent travel. The history goes back ten days prior to presentation when the patient was evaluated at an outside institution for persistent headaches and gait ataxia. The patient was presumed to have metabolic encephalopathy and was admitted to the rehabilitation ward for further evaluation of the gait disturbance. He was transferred back to the medical ward for change in mental status and worsening encephalopathy. Over the next 48 hours, the patient had fever above 101°F. A lumbar puncture was conducted and revealed clear and colorless CSF. The CSF gram stain showed the presence of budding yeast and India ink stain was positive (See figure below). The patient was started on intravenous amphotericin B and flucytosine.Q3. Which of the following antifungals has high CNS penetration and has been proven effective in the treatment of crytpococcal meningitis?

A. Capsofungin
B. Fluconazole
C. Itraconazole
D. Micafungin
E. Ketoconazole

Answer 45

Fluconazole

Question 46

A 62-year-old patient was admitted for unremitting, severe, right frontal headache, gait ataxia, and slurred speech for the preceding five days. His past medical history was notable for insulin-dependent diabetes, hypertension, and mitral valve replacement. The patient’s wife denied recent travel. The history goes back ten days prior to presentation when the patient was evaluated at an outside institution for persistent headaches and gait ataxia. The patient was presumed to have metabolic encephalopathy and was admitted to the rehabilitation ward for further evaluation of the gait disturbance. He was transferred back to the medical ward for change in mental status and worsening encephalopathy. Over the next 48 hours, the patient had fever above 101°F. A lumbar puncture was conducted and revealed clear and colorless CSF. The CSF gram stain showed the presence of budding yeast and India ink stain was positive (See figure below). The patient was started on intravenous amphotericin B and flucytosine.Which of the following sites (A, B, C, D or E) on the figure represents the site of action of flucytosine

Answer 46

C

Question 47

A 62-year-old patient was admitted for unremitting, severe, right frontal headache, gait ataxia, and slurred speech for the preceding five days. His past medical history was notable for insulin-dependent diabetes, hypertension, and mitral valve replacement. The patient’s wife denied recent travel. The history goes back ten days prior to presentation when the patient was evaluated at an outside institution for persistent headaches and gait ataxia. The patient was presumed to have metabolic encephalopathy and was admitted to the rehabilitation ward for further evaluation of the gait disturbance. He was transferred back to the medical ward for change in mental status and worsening encephalopathy. Over the next 48 hours, the patient had fever above 101°F. A lumbar puncture was conducted and revealed clear and colorless CSF. The CSF gram stain showed the presence of budding yeast and India ink stain was positive (See figure below). The patient was started on intravenous amphotericin B and flucytosine.Flucytosine is a fluorinated antifungal prodrug. Which of the following statements best describes the mechanism of action of flucytosine?

A. Flucytosine is activated by fungal Cytosine Decarboxylase to 5-Fluorouracil
B. Flucytosine is activated by fungal Cytosine Decarboxylase to 5-Fluorodeoxyuridine
C. Flucytosine is activated by fungal Cytosine Deaminase to 5-Fluorodeoxyuridne
D. Flucytosine is activated by fungal Cytosine Dioxygenase to 5-Fluorouracil
E. Flucytosine is activated by fungal Cytosine Deaminase to 5-Fluorouracil

Answer 47

Flucytosine is activated by fungal Cytosine Deaminase to 5-Fluorouracil

Question 48

Antiretroviral (ART) is recommended for everyone infected with HIV. ART helps HIV patients live longer, healthier lives and reduces the risk of HIV transmission.
Which of the following ART regimens is the least appropriate drug combination due to antagonistic effect on HIV 1?

A. ATV + IDV 
B. ddI + TDF
C. 2 NNRTIs
D. d4T + ZDV
E. ddI + d4T

Answer 48

d4T + d4T + ZDV