Drug interactions
Avapritinib + Clemastine
Severity: Moderate
Avapritinib and Clemastine: 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
Avapritinib can cause cognitive effects such as memory impairment, confusion and somnolence, and a sedating antihistamine may add to these CNS effects. Clemastine is not an established CYP3A4 inhibitor, so the concern is mainly additive CNS effects.
What this interaction means in plain words
Avapritinib and Clemastine 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.
Avapritinib belongs to Oncology; Clemastine belongs to Respiratory.
Why it happens
Additive CNS depression; no established pharmacokinetic interaction.
What to do
Monitor for worsening cognitive impairment, confusion or sedation. Consider a non-sedating antihistamine.
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 Clemastine
Other interactions of Avapritinib
Frequently asked questions
Can I take Avapritinib with Clemastine?
MediHelp rates the interaction as moderate. Avapritinib and Clemastine 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. Avapritinib can cause cognitive effects such as memory impairment, confusion and somnolence, and a sedating antihistamine may add to these CNS effects. Clemastine is not an established CYP3A4 inhibitor, so the concern is mainly additive CNS effects.
How serious is the interaction between Avapritinib and Clemastine?
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 for worsening cognitive impairment, confusion or sedation. Consider a non-sedating antihistamine.
What other medicines interact with Clemastine?
MediHelp also lists interactions of Clemastine with, for example, Alfentanil, Benzhydrocodone / acetaminophen, Buprenorphine buccal. The full list is on the Clemastine page.
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