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Benign prostatic enlargement with treated voiding LUTS — MSRA MCQ

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HardBPHBenign prostatic enlargement with treated voiding LUTSMSRA

A 74-year-old man takes alfuzosin XL 10 mg once daily for bothersome voiding LUTS attributed to benign prostatic enlargement. His symptoms are well controlled and he has had no previous urinary retention. He develops symptomatic COVID-19 and, following assessment by the local COVID medicines service, is otherwise eligible for treatment with nirmatrelvir/ritonavir. His eGFR is 68 mL/min/1.73 m² and liver function is normal. His only other regular medicine is levothyroxine. What is the most appropriate pharmacological plan?

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Correct answer: DDo not prescribe nirmatrelvir/ritonavir and arrange assessment for an alternative COVID-19 treatment

Alfuzosin is contraindicated with nirmatrelvir/ritonavir (Paxlovid). Ritonavir is a potent CYP3A4 inhibitor and can substantially increase alfuzosin exposure, risking severe hypotension. Therefore, nirmatrelvir/ritonavir should not be prescribed; the COVID medicines service should consider an alternative appropriate treatment. Temporarily stopping alfuzosin may initially appear attractive because alfuzosin is not required to treat an immediately life-threatening condition. However, the Paxlovid SmPC specifies concomitant alfuzosin as a contraindication rather than providing a withholding-and-restarting strategy. In addition, alfuzosin interruption could precipitate recurrent troublesome obstruction or retention. Dose reduction of Paxlovid does not address the interaction, because the mechanism is ritonavir-mediated inhibition of alfuzosin metabolism. Switching to tamsulosin is also inappropriate: tamsulosin exposure can rise with strong CYP3A4 inhibitors and its SmPC advises caution with ritonavir. Monitoring blood pressure does not make a formally contraindicated combination acceptable, since severe hypotension may occur unpredictably.

Reference: Paxlovid 150 mg/100 mg film-coated tablets - Summary of Product Characteristics (Updated 2026) — https://www.medicines.org.uk/emc/product/13145/smpc Tamsulosin hydrochloride SUN Pharma 400 micrograms prolonged-release hard capsules - Summary of Product Characteristics (Updated 2025) — https://www.medicines.org.uk/emc/product/2508/smpc NICE CG97: Lower urinary tract symptoms in men: management - Drug treatment (Last reviewed December 2024) — https://www.nice.org.uk/guidance/cg97/chapter/recommendations