Drug interactions
Losartan + Lumacaftor / ivacaftor
Severity: Minor
Losartan and Lumacaftor / ivacaftor: 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
Lumacaftor is an enzyme inducer and ivacaftor a weak inhibitor, so the net effect on CYP2C9 substrates such as losartan is unpredictable. Conversion of losartan to its active metabolite may change, altering blood pressure control.
What this interaction means in plain words
Losartan and Lumacaftor / ivacaftor 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
Opposing in vitro effects on CYP2C9: induction by lumacaftor and inhibition by ivacaftor, with net effect not established.
What to do
Monitor blood pressure after starting or stopping lumacaftor/ivacaftor and adjust the losartan dose if control changes.
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 Losartan
- Aliskiren + Losartan Contraindicated
- Losartan + Sparsentan Contraindicated
- Amifostine + Losartan Major
- Amiloride + Losartan Major
- Amlodipine-benazepril + Losartan Major
- Amlodipine-hydrochlorothiazide-valsartan + Losartan Major
Frequently asked questions
Can I take Losartan with Lumacaftor / ivacaftor?
MediHelp rates the interaction as minor. Losartan and Lumacaftor / ivacaftor have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Lumacaftor is an enzyme inducer and ivacaftor a weak inhibitor, so the net effect on CYP2C9 substrates such as losartan is unpredictable. Conversion of losartan to its active metabolite may change, altering blood pressure control.
How serious is the interaction between Losartan and Lumacaftor / ivacaftor?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor blood pressure after starting or stopping lumacaftor/ivacaftor and adjust the losartan dose if control changes.
What other medicines interact with Losartan?
MediHelp also lists interactions of Losartan with, for example, Aliskiren, Sparsentan, Amifostine. The full list is on the Losartan page.
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