Drug interactions
Methylphenidate + Promethazine
Severity: Moderate
Methylphenidate and Promethazine: 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
Promethazine's dopamine-blocking and sedating properties may oppose the stimulant effect of methylphenidate. Both drugs can also lower the seizure threshold, and each can alter heart rate, so the combination offers little benefit and some added risk.
What this interaction means in plain words
Methylphenidate and Promethazine 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.
Methylphenidate belongs to Central Nervous System; Promethazine belongs to Respiratory.
Why it happens
Pharmacodynamic opposition via dopamine blockade and sedation; additive effects on seizure threshold and heart rate.
What to do
Monitor therapeutic response, heart rate, blood pressure and seizure activity. Consider an alternative antiemetic or antihistamine if the stimulant effect is reduced.
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 Promethazine
- Ibutilide + Promethazine Contraindicated
- Pimozide + Promethazine Contraindicated
- Promethazine + Thioridazine Contraindicated
- Alfentanil + Promethazine Major
- Amiodarone + Promethazine Major
- Amisulpride + Promethazine Major
Other interactions of Methylphenidate
- Isocarboxazid + Methylphenidate Contraindicated
- Linezolid + Methylphenidate Contraindicated
- Methylphenidate + Phenelzine Contraindicated
- Methylphenidate + Procarbazine Contraindicated
- Methylphenidate + Rasagiline Contraindicated
- Methylphenidate + Safinamide Contraindicated
Frequently asked questions
Can I take Methylphenidate with Promethazine?
MediHelp rates the interaction as moderate. Methylphenidate and Promethazine 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. Promethazine's dopamine-blocking and sedating properties may oppose the stimulant effect of methylphenidate. Both drugs can also lower the seizure threshold, and each can alter heart rate, so the combination offers little benefit and some added risk.
How serious is the interaction between Methylphenidate and Promethazine?
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 therapeutic response, heart rate, blood pressure and seizure activity. Consider an alternative antiemetic or antihistamine if the stimulant effect is reduced.
What other medicines interact with Promethazine?
MediHelp also lists interactions of Promethazine with, for example, Ibutilide, Pimozide, Thioridazine. The full list is on the Promethazine page.
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