Pediatric Examination and Board Review (174 page)

SELECT THE ONE BEST ANSWER

1.
Before transplant it was known that the child was seronegative for CMV and the donor of the kidney was seropositive. The antiviral agent of choice for prophylaxis of CMV infection is

(A) acyclovir

(B) cidofovir

(C) foscarnet

(D) ganciclovir

(E) zidovudine

2.
The mother of the child asks you about adverse effects that can occur with the use of ganciclovir. You tell the mother that the most important toxic effect of ganciclovir is

(A) anemia

(B) neutropenia

(C) hallucinations

(D) hepatitis

(E) renal toxicity

3.
The mechanism of action of ganciclovir includes

(A) prevention of viral entry into the host cell

(B) prevention of viral transcription by inhibiting viral DNA polymerase

(C) interrupting viral protein assembly

(D) modulation of host response to infection

(E) inhibition of the reverse transcriptase enzyme

4.
An 1800-g infant is born at 35 weeks’ gestation. Growth parameters are consistent with intrauterine growth retardation including microcephaly. The infant has scattered petechiae as well as hepatosplenomegaly. The diagnosis of congenital CMV infection is confirmed by detection of virus in sequential urine specimens. IV ganciclovir is discussed with the parents as a treatment option. The major benefit of IV ganciclovir in this clinical setting is

(A) prevention of sensorineural hearing loss

(B) more rapid resolution of hepatosplenomegaly

(C) more rapid resolution of CMV retinitis

(D) improved weight gain and head circumference growth

(E) more rapid resolution of thrombocytopenia

5.
A 3-year-old child is hospitalized for repair of congenital heart disease. Influenza B is known to be present in the community, and there has been influenza B infection in several staff members. The child did not receive influenza vaccine. The best initial management is

(A) initiation of zanamivir chemoprophylaxis

(B) vaccination with whole virus influenza vaccine

(C) vaccination with live attenuated influenza vaccine

(D) initiation of rimantadine chemoprophylaxis

(E) initiation of oseltamivir chemoprophylaxis

6.
You are asked about the activity and treatment of antiviral agents against influenza. Which of the following antiviral agents are active against influenza A and influenza B and approved for treatment of infection caused by both viruses?

(A) amantadine

(B) rimantadine

(C) zanamivir

(D) interferon-alpha

(E) ribavirin

7.
A 15-year-old adolescent female develops a fever of 104°F (40°C), cough, rhinorrhea, headache, sore throat, and myalgias during the middle of an epidemic of influenza A. You are considering prescribing oseltamivir for treatment. Recommendations for use of oseltamivir include starting the medication within which of the following number of days of symptoms of influenza?

(A) 1 day

(B) 2 days

(C) 3 days

(D) 4 days

(E) 7 days

8.
For another patient, you are asked about the potential indications for acyclovir use. The infection for which your patient is most likely to benefit from the use of acyclovir is

(A) a 14-year-old adolescent female with an initial genital herpes infection that began 2 days ago

(B) a 2-week-old female infant with microcephaly, hepatosplenomegaly, and shedding CMV in the urine

(C) a 3-year-old with hepatitis associated with varicella zoster virus infection that began 2 days ago

(D) a 2-year-old boy with encephalitis caused by human HHV type VI

(E) a 15-month old healthy infant with adenovirus pneumonia

9.
You are asked about the mechanism of action of acyclovir by a group of medical students. You reply that

(A) acyclovir in its triphosphate form inhibits the viral DNA polymerase of HSV

(B) acyclovir has metabolites that interfere with elongation of viral messenger RNA during HSV infection

(C) acyclovir results in the methylation of viral messenger RNA during HSV infection

(D) acyclovir interferes with viral protein synthesis in HSV

(E) acyclovir inhibits the reverse transcriptase enzyme in HSV

10.
The most serious side effect of acyclovir is

(A) acute renal failure

(B) hematuria

(C) neurotoxicity

(D) hypoglycemia

(E) neutropenia

11.
You are asked about the appropriate indications for the use of foscarnet. Of the following indications listed, the one in which foscarnet would not be appropriate includes

(A) CMV retinitis in a 19-year-old man with AIDS

(B) CMV infection that is unresponsive to ganciclovir in an 18-month-old child, a renal transplant recipient

(C) primary acyclovir resistant varicella in an 8-year-old girl with ALL

(D) Parainfluenza virus pneumonia in a 12-year-old boy with leukemia

(E) mucocutaneous acyclovir-resistant HSV infection in a 3-year-old child post a stem cell transplant

12.
The most common serious adverse effect of foscarnet includes

(A) hypocalcemia

(B) neutropenia

(C) pancreatitis

(D) seizures

(E) nephrotoxicity

13.
A 6-year-old Asian boy with perinatal hepatitis B infection has persistent hepatitis B surface antigen (HBsAg) in serum, no hepatitis B surface antibody (Anti-HBs), and a positive hepatitis B e antigen (HBeAg). These findings are consistent with chronic hepatitis B infection. An appropriate antiviral agent for treatment of this infection includes

(A) cidofovir

(B) interferon-alpha

(C) trifluridine

(D) vidarabine

(E) zidovudine

14.
The most likely adverse reaction associated with the first week of therapy of the child with chronic hepatitis B infection in the previous question is

(A) influenza-like illness with fever, chills, headache, myalgias, arthralgias

(B) seizures

(C) anemia

(D) renal insufficiency

(E) neutropenia

15.
An 8-year-old girl recently diagnosed with HIV infection has a CD4 count of 400/μL. The viral load measured is 100,500 copies/mL. Initial management regarding antiretroviral therapy for children and adolescents with HIV infection can include any of the following except

(A) 2 nucleoside reverse transcriptase inhibitor (NRTIs) plus one PI

(B) 2 NRTIs plus one nonnucleoside reverse transcriptase inhibitor (NNRTI)

(C) 3 NRTIs

(D) 1 NRTI

(E) none of the above

16.
Monotherapy with an antiretroviral agent is recommended in which of the following circumstances

(A) 14-year-old adolescent with a CD4 count of 300/μL and suspected poor compliance

(B) newborn infant born to an HIV-positive mother

(C) 6-month-old infant girl with viral load of 50,000 copies/mL and a CD4 count of 750/μL

(D) 10-year-old girl with a newly diagnosed HIV infection, detectable viral load, a CD4 count of 650, and percentage of 33%

(E) a 6-year-old asymptomatic child with a CD4 count of 500/μL and viral load of 10,000 copies/mL

17.
The major toxicity associated with zidovudine in children is

(A) anemia

(B) lactic acidosis

(C) pancreatitis

(D) peripheral neuropathy

(E) diarrhea

18.
You are considering using a protease inhibitor in a highly active antiretroviral combination regimen for treatment of HIV infection in a pediatric patient. Protease class disadvantages include all but

(A) metabolic complications including dyslipidemia, fat maldistribution, and insulin resistance

(B) higher pill burden than nucleoside or nonnucleoside analog reverse transcriptase inhibitorbased regimens

(C) poor palatability of liquid preparations

(D) common adverse reactions including diarrhea, nausea, and vomiting

(E) resistance that requires only a single mutation in the protease enzyme

ANSWERS

1.
(D)
For renal transplant recipients, antiviral therapy is recommended when the recipient is seronegative for CMV and the donor is seropositive. If the donor or recipient is seropositive for CMV and antilymphocyte treatment is used, antiviral therapy is also recommended. In one comparative trial of antiviral therapy for CMV prophylaxis among kidney transplant recipients, ganciclovir was superior to acyclovir.

2.
(B)
Myelosuppression is the most frequent toxic effect of ganciclovir. The incidence of neutropenia is 40%. Thrombocytopenia occurs in 20% of patients and anemia in 2% of ganciclovir recipients. Hallucinations and hepatitis are rare adverse events associated with ganciclovir.

3.
(B)
Ganciclovir is a nucleoside analog that is phosphorylated first by virus-encoded enzymes and then by cellular enzymes. Ganciclovir triphosphate is a competitive inhibitor of herpes viral DNA polymerase but has some activity against cellular DNA polymerases.

4.
(A)
A randomized controlled trial of neonates with symptomatic CMV disease involving the central nervous system (CNS) found that neonates treated with 6 weeks of IV ganciclovir prevented hearing deterioration at 6 months of age and may prevent hearing loss at 1 year of age or older. Neutropenia is a significant side effect of the therapy.

5.
(E)
Chemoprophylaxis for prevention of influenza A and B is indicated to protect high-risk children (eg, patients with congenital heart disease during the 2 weeks after immunization while an immune response is developing or if the child is immunized after influenza is circulating in the community). In addition to receiving oseltamivir for chemoprophylaxis, influenza vaccine should also be administered to a 3-year-old child. Two doses will be required if there is no previous exposure with influenza vaccines. Zanamivir is licensed for prophylaxis against influenza A and B for children 5 years of age and older and oseltamivir for children 1 year of age and older. Awareness of influenza A resistance patterns provided by state and local health departments through the CDC is extremely important in deciding appropriate chemoprophylaxis for influenza.