Drug interactions
Hydrochlorothiazide-losartan + Nirmatrelvir / ritonavir
Severity: Minor
Hydrochlorothiazide-losartan and Nirmatrelvir / ritonavir: minor interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Ritonavir strongly inhibits CYP3A4 and may weakly induce CYP2C9, so losartan exposure or active metabolite formation could change unpredictably. A short course of nirmatrelvir/ritonavir is unlikely to cause important blood pressure changes, though effects are not well characterised.
What this interaction means in plain words
Hydrochlorothiazide-losartan and Nirmatrelvir / ritonavir have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Why it happens
Ritonavir modulation of CYP3A4 and CYP2C9 metabolism of losartan; net effect uncertain.
What to do
No empirical dose change is needed for the 5-day course; monitor blood pressure and symptoms of hypotension.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Hydrochlorothiazide-losartan
- Aliskiren + Hydrochlorothiazide-losartan Contraindicated
- Dofetilide + Hydrochlorothiazide-losartan Contraindicated
- Hydrochlorothiazide-losartan + Sparsentan Contraindicated
- Aceclofenac + Hydrochlorothiazide-losartan Major
- Aldesleukin + Hydrochlorothiazide-losartan Major
- Amifostine + Hydrochlorothiazide-losartan Major
Frequently asked questions
Can I take Hydrochlorothiazide-losartan with Nirmatrelvir / ritonavir?
MediHelp rates the interaction as minor. Hydrochlorothiazide-losartan and Nirmatrelvir / ritonavir have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Ritonavir strongly inhibits CYP3A4 and may weakly induce CYP2C9, so losartan exposure or active metabolite formation could change unpredictably. A short course of nirmatrelvir/ritonavir is unlikely to cause important blood pressure changes, though effects are not well characterised.
How serious is the interaction between Hydrochlorothiazide-losartan and Nirmatrelvir / ritonavir?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No empirical dose change is needed for the 5-day course; monitor blood pressure and symptoms of hypotension.
What other medicines interact with Hydrochlorothiazide-losartan?
MediHelp also lists interactions of Hydrochlorothiazide-losartan with, for example, Aliskiren, Dofetilide, Sparsentan. The full list is on the Hydrochlorothiazide-losartan page.
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