Drug interactions
Hydrochlorothiazide-losartan + Istradefylline
Severity: Minor
Hydrochlorothiazide-losartan and Istradefylline: 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
Istradefylline at the 40 mg daily dose inhibits CYP3A4 and can raise exposure to sensitive CYP3A4 substrates. Losartan is metabolized partly by CYP3A4 and CYP2C9 to its active metabolite, so the effect on antihypertensive response is unclear and probably small.
What this interaction means in plain words
Hydrochlorothiazide-losartan and Istradefylline have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Hydrochlorothiazide-losartan belongs to Cardiovascular; Istradefylline belongs to Central Nervous System.
Why it happens
Istradefylline weakly inhibits CYP3A4 at higher doses, which may alter losartan metabolism to a limited degree.
What to do
No dose change is generally needed; monitor blood pressure when istradefylline is started or the dose is increased to 40 mg.
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
Other interactions of Istradefylline
Frequently asked questions
Can I take Hydrochlorothiazide-losartan with Istradefylline?
MediHelp rates the interaction as minor. Hydrochlorothiazide-losartan and Istradefylline have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Istradefylline at the 40 mg daily dose inhibits CYP3A4 and can raise exposure to sensitive CYP3A4 substrates. Losartan is metabolized partly by CYP3A4 and CYP2C9 to its active metabolite, so the effect on antihypertensive response is unclear and probably small.
How serious is the interaction between Hydrochlorothiazide-losartan and Istradefylline?
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 dose change is generally needed; monitor blood pressure when istradefylline is started or the dose is increased to 40 mg.
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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