Promethazine · Medicine question

How can promethazine affect amitriptyline blood levels?

iatroX medicinesPublished 8 November 2026

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Promethazine taken with amitriptyline may increase amitriptyline plasma levels through a possible CYP2D6 interaction, so patients should be monitored for dose-dependent adverse reactions.

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Phenergan ElixirOpella Healthcare UK Limited · emc · SmPC §4.5 Interaction with other medicinal products · Version 19Document updated 9 July 2024

Sources checked 8 November 2026

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