Drug interactions
Cetirizine + Istradefylline
Severity: Minor
Cetirizine 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 40 mg/day raises exposure to P-glycoprotein substrates, and cetirizine is a P-gp substrate. Cetirizine concentrations may rise, with more sedation or anticholinergic-type effects.
What this interaction means in plain words
Cetirizine 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.
Cetirizine belongs to Respiratory; Istradefylline belongs to Central Nervous System.
Why it happens
Istradefylline inhibits intestinal P-glycoprotein efflux, increasing absorption of cetirizine.
What to do
Monitor for increased drowsiness; consider reducing the cetirizine dose if adverse effects appear.
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 Cetirizine
- Acrivastine + Cetirizine Moderate
- Amisulpride + Cetirizine Moderate
- Asenapine + Cetirizine Moderate
- Avapritinib + Cetirizine Moderate
- Benzhydrocodone / acetaminophen + Cetirizine Moderate
- Brexpiprazole + Cetirizine Moderate
Other interactions of Istradefylline
Frequently asked questions
Can I take Cetirizine with Istradefylline?
MediHelp rates the interaction as minor. Cetirizine 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 40 mg/day raises exposure to P-glycoprotein substrates, and cetirizine is a P-gp substrate. Cetirizine concentrations may rise, with more sedation or anticholinergic-type effects.
How serious is the interaction between Cetirizine 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: Monitor for increased drowsiness; consider reducing the cetirizine dose if adverse effects appear.
What other medicines interact with Cetirizine?
MediHelp also lists interactions of Cetirizine with, for example, Acrivastine, Amisulpride, Asenapine. The full list is on the Cetirizine page.
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