CSP - Certified Specialty Pharmacist Clinical Management: Infectious Disease Questions and Answers — Questions and Answers
Question 1: A patient is being initiated on sofosbuvir/velpatasvir for Hepatitis C genotype 1. Their current medication list includes amlodipine, lisinopril, rosuvastatin 20 mg daily, and omeprazole 40 mg daily. Which of the following recommendations is most appropriate for the specialty pharmacist to make?
- Advise the patient to take the sofosbuvir/velpatasvir with food, four hours before the omeprazole. (Correct answer)
- Discontinue rosuvastatin for the duration of Hepatitis C therapy.
- Switch omeprazole to famotidine 40 mg twice daily.
- Recommend taking sofosbuvir/velpatasvir and omeprazole at the same time to improve adherence.
Correct answer: Advise the patient to take the sofosbuvir/velpatasvir with food, four hours before the omeprazole.
Velpatasvir's absorption is pH-dependent and is reduced by acid-lowering agents. Co-administration with proton-pump inhibitors (PPIs) like omeprazole is generally not recommended. However, if medically necessary, sofosbuvir/velpatasvir should be administered with food and taken 4 hours before a low dose of omeprazole (e.g., 20 mg).
Question 2: According to the 2021 IDSA/SHEA guidelines for an initial episode of non-severe Clostridioides difficile infection (CDI), which of the following is the preferred treatment?
- Metronidazole 500 mg orally three times daily for 10 days
- Vancomycin 125 mg orally four times daily for 10 days
- Fidaxomicin 200 mg orally twice daily for 10 days (Correct answer)
- Rifaximin 400 mg orally three times daily for 20 days following a course of vancomycin
Correct answer: Fidaxomicin 200 mg orally twice daily for 10 days
The 2021 focused update from IDSA/SHEA suggests using fidaxomicin over a standard course of vancomycin for an initial CDI episode. This is a conditional recommendation based on moderate certainty of evidence, placing a high value on fidaxomicin's beneficial effects, though vancomycin remains an acceptable alternative.
Question 3: A 35-year-old male patient with HIV is diagnosed with latent tuberculosis infection (LTBI). His current antiretroviral therapy (ART) is Biktarvy® (bictegravir/emtricitabine/tenofovir alafenamide). Which of the following is a preferred and appropriate treatment regimen for his LTBI?
- Isoniazid 300 mg daily for 9 months (Correct answer)
- Rifampin 600 mg daily for 4 months
- Isoniazid and rifapentine once weekly for 3 months (3HP)
- Levofloxacin 750 mg daily for 6 months
Correct answer: Isoniazid 300 mg daily for 9 months
Nine months of daily isoniazid is a standard and effective treatment for latent TB infection in people with HIV and can be co-administered with any antiretroviral regimen, including Biktarvy®. Rifamycin-based regimens (like those containing rifampin or rifapentine) have significant drug-drug interactions with many ART components, including integrase inhibitors like bictegravir, making isoniazid monotherapy a safer and preferred choice in this scenario.
Question 4: A specialty pharmacist is counseling a patient who is starting on daily oral emtricitabine/tenofovir alafenamide (F/TAF) for HIV pre-exposure prophylaxis (PrEP). Which of the following is a critical initial assessment that must be confirmed before dispensing the first fill?
- The patient's hepatitis C virus (HCV) antibody status.
- A negative HIV test result at or very near the time of initiation. (Correct answer)
- The patient's complete blood count (CBC) from the last 6 months.
- A baseline bone mineral density (BMD) scan.
Correct answer: A negative HIV test result at or very near the time of initiation.
It is imperative to confirm that a patient is HIV-negative before starting PrEP. Initiating a two-drug regimen like F/TAF in a person with undiagnosed acute or established HIV can lead to the development of drug resistance, complicating future treatment options.
Question 5: Which of the following laboratory parameters is essential to obtain at baseline before initiating any direct-acting antiviral (DAA) regimen for Hepatitis C virus (HCV) infection?
- Serum Vitamin D level
- Urinalysis for protein
- Hepatitis A total antibody
- Complete blood count (CBC) and a hepatic function panel (Correct answer)
Correct answer: Complete blood count (CBC) and a hepatic function panel
Guidelines recommend several baseline laboratory tests within 6 months of starting DAA therapy, including a complete blood count (CBC), international normalized ratio (INR), and a hepatic function panel (albumin, bilirubin, ALT, AST). These tests help assess the patient's liver disease severity and overall health status before treatment.
Question 6: A patient being treated with a direct-acting antiviral (DAA) for HCV calls the specialty pharmacy concerned because they had a quantitative HCV RNA level drawn at week 4 of therapy, and it was still detectable, though low. What is the most appropriate response from the pharmacist?
- Inform the patient this indicates imminent treatment failure and to contact their provider immediately.
- Advise the patient to stop therapy, as it is clearly not working.
- Reassure the patient that low-level quantifiable HCV RNA during DAA therapy does not predict treatment failure and to continue the regimen as prescribed. (Correct answer)
- Recommend doubling the dose of the DAA for the remainder of the treatment course.
Correct answer: Reassure the patient that low-level quantifiable HCV RNA during DAA therapy does not predict treatment failure and to continue the regimen as prescribed.
Unlike older interferon-based therapies, on-treatment virologic monitoring is not typically necessary with DAA regimens because a detectable viral load during treatment, especially early on, does not predict failure. The key measure of success is achieving a sustained virologic response (SVR), which is an undetectable viral load 12 weeks after completing therapy.
CSP - Certified Specialty Pharmacist Clinical Management: Infectious Disease Questions and Answers
A patient is being initiated on sofosbuvir/velpatasvir for Hepatitis C genotype 1.
Their current medication list includes amlodipine, lisinopril, rosuvastatin 20 mg daily, and omeprazole 40 mg daily.
Which of the following recommendations is most appropriate for the specialty pharmacist to make?