Drug interactions
Hydrochlorothiazide-losartan + Ritonavir
Severity: Moderate
Hydrochlorothiazide-losartan and Ritonavir: moderate 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 inhibits CYP3A4 and can raise losartan exposure, while it also induces CYP2C9 with prolonged use, so the net effect is uncertain. Hypotension or reduced blood pressure effect may occur.
What this interaction means in plain words
Hydrochlorothiazide-losartan and Ritonavir can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Hydrochlorothiazide-losartan belongs to Cardiovascular; Ritonavir belongs to Anti Virals.
Why it happens
Mixed CYP3A4 inhibition and CYP2C9 induction by ritonavir altering losartan metabolism.
What to do
Monitor blood pressure and renal function when starting or stopping ritonavir and adjust losartan accordingly.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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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
Other interactions of Ritonavir
- Alfuzosin + Ritonavir Contraindicated
- Amiodarone + Ritonavir Contraindicated
- Avanafil + Ritonavir Contraindicated
- Colchicine + Ritonavir Contraindicated
- Dronedarone + Ritonavir Contraindicated
- Eletriptan + Ritonavir Contraindicated
Frequently asked questions
Can I take Hydrochlorothiazide-losartan with Ritonavir?
MediHelp rates the interaction as moderate. Hydrochlorothiazide-losartan and Ritonavir can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Ritonavir inhibits CYP3A4 and can raise losartan exposure, while it also induces CYP2C9 with prolonged use, so the net effect is uncertain. Hypotension or reduced blood pressure effect may occur.
How serious is the interaction between Hydrochlorothiazide-losartan and Ritonavir?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor blood pressure and renal function when starting or stopping ritonavir and adjust losartan accordingly.
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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