Maraviroc is an antiretroviral used in treatment-experienced HIV patients. It acts by blocking the CCR5 coreceptor on CD4+ T cells. Before initiating maraviroc therapy, which test is mandatory?
- A HLA B*5701 genotyping
- B HIV tropism assay (Trofile) ✓
- C Hepatitis B surface antigen
- D Serum creatinine and eGFR
Correct answer: B. HIV tropism assay (Trofile)
Explanation
Maraviroc blocks the CCR5 coreceptor and is effective only against CCR5-tropic HIV. Some patients harbor CXCR4-tropic or dual/mixed-tropic virus, which maraviroc cannot block. A tropism assay such as the Trofile test must confirm CCR5 tropism before use. HLA B*5701 screening is required before abacavir, not maraviroc.
Reference: Katzung Basic and Clinical Pharmacology, 15th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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