Drug interactions
Lisdexamfetamine + Promazine
Severity: Moderate
Lisdexamfetamine and Promazine: 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
Both drugs can affect cardiac conduction, and phenothiazines such as promazine may prolong the QT interval while amphetamines can raise heart rate and provoke arrhythmias. Their combined use may increase arrhythmia risk in predisposed patients. Phenothiazines may also blunt stimulant effects through dopamine blockade.
What this interaction means in plain words
Lisdexamfetamine and Promazine 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.
Why it happens
Additive cardiac effects (QT prolongation with sympathomimetic stimulation) and opposing dopaminergic activity.
What to do
Obtain a baseline ECG in patients with cardiac risk factors and correct potassium and magnesium disturbances. Avoid the combination in patients with QT prolongation or structural heart disease.
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 Lisdexamfetamine
- Isocarboxazid + Lisdexamfetamine Contraindicated
- Linezolid + Lisdexamfetamine Contraindicated
- Lisdexamfetamine + Phenelzine Contraindicated
- Lisdexamfetamine + Procarbazine Contraindicated
- Lisdexamfetamine + Rasagiline Contraindicated
- Lisdexamfetamine + Safinamide Contraindicated
Frequently asked questions
Can I take Lisdexamfetamine with Promazine?
MediHelp rates the interaction as moderate. Lisdexamfetamine and Promazine 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. Both drugs can affect cardiac conduction, and phenothiazines such as promazine may prolong the QT interval while amphetamines can raise heart rate and provoke arrhythmias. Their combined use may increase arrhythmia risk in predisposed patients. Phenothiazines may also blunt stimulant effects through dopamine blockade.
How serious is the interaction between Lisdexamfetamine and Promazine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Obtain a baseline ECG in patients with cardiac risk factors and correct potassium and magnesium disturbances. Avoid the combination in patients with QT prolongation or structural heart disease.
What other medicines interact with Lisdexamfetamine?
MediHelp also lists interactions of Lisdexamfetamine with, for example, Isocarboxazid, Linezolid, Phenelzine. The full list is on the Lisdexamfetamine page.
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