WBR0392
| Author | [[PageAuthor::Rim Halaby, M.D. [1]]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Pharmacology |
| Sub Category | SubCategory::Infectious Disease |
| Prompt | [[Prompt::A 35-year-old male, previously diagnosed with HIV, presents to the infectious disease clinic for a standard follow-up. His last CD4 count, 3 months ago, was 670 cells/mm3 and his viral load was low to undetectable. Twice in the past month, the patient was admitted to the hospital for a community acquired pneumonia and gastroenteritis. His recent tests demonstrate a CD4 count of 231 cells/mm3 and a viral load of 325000 copies/ml. Based on the recent findings, you decide to initiate highly active antiretroviral therapy (HAART) in the patient. Which of the following drug regimens is most suitable for this patient?]] |
| Answer A | AnswerA::Tenofovir + emtricitabine + abacavir |
| Answer A Explanation | AnswerAExp::This combination has 3 NRTIs, a combination that is usually not recommended. |
| Answer B | AnswerB::Darunavir + raltegravir + lamivudine |
| Answer B Explanation | AnswerBExp::This combination has only 1 NRTI a combination that is usually not recommended. Darunavir is a protease inhibitor while raltegravir is an integrase inhibitor. |
| Answer C | AnswerC::Efavirenz + tenofovir + nevirapine |
| Answer C Explanation | AnswerCExp::This combination has only 1 NRTI a combination that is usually not recommended. Efavirenz and nevirapine are both NNTRIs. |
| Answer D | AnswerD::Ritonavir + tenofovir + lopinavir |
| Answer D Explanation | AnswerDExp::This combination has only 1 NRTI. Ritonavir and lopinavir are both protease inhibitors. |
| Answer E | AnswerE::Raltegravir + tenofovir + emtricitabine |
| Answer E Explanation | AnswerEExp::This combination is suitable since it contains 2 NRTIs (tenofovir + emtricitabine) and 1 integrase inhibitor. |
| Right Answer | RightAnswer::E |
| Explanation | [[Explanation::Highly active antiretroviral therapy (HAART) was introduced in 1995 after early regimens that consisted of only 2 drugs against HIV failed to sustain a therapeutic benefit. HAART consists of three or more agents and has been associated with a remarkable improvement in clinical outcomes. The CD4 count and viral load are the two lab markers followed to determine the best time for initiation of HAART. A CD4 count below 350 cells/mm3 and any AIDS-defining illness usually indicate the need for therapy. Viral loads >100000 copies/ml are not an absolute indication for treatment, and some physicians opt to wait depending on the CD4 counts. The recommended regimens usually include a combination of 2 nucleoside reverse transcriptase inhibitors (NRTIs) with either a non-nucleoside reverse transcriptase inhibitor (NNRTI), a protease inhibitor, or an integrase inhibitor. The most commonly used combinations include:
Educational Objective: HAART consists of three or more agents usually a combination of 2 nucleoside reverse transcriptase inhibitors (NRTIs) with either a non-nucleoside reverse transcriptase inhibitor (NNRTI), a protease inhibitor, or an integrase inhibitor. |
| Approved | Approved::No |
| Keyword | WBRKeyword::HAART therapy, WBRKeyword::HIV, WBRKeyword::AIDS, WBRKeyword::CD4 count, WBRKeyword::HIV drug combinations |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |