Drug interactions
Fluphenazine + Pseudoephedrine
Severity: Moderate
Fluphenazine and Pseudoephedrine: 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
Phenothiazines can cause QT prolongation and alpha-blockade, while pseudoephedrine stimulates the heart and raises blood pressure. The combination may increase arrhythmia risk in predisposed patients, though evidence is limited.
What this interaction means in plain words
Fluphenazine and Pseudoephedrine 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.
Fluphenazine belongs to Central Nervous System; Pseudoephedrine belongs to Respiratory.
Why it happens
Pharmacodynamic: phenothiazine effects on QT and alpha-blockade versus sympathomimetic cardiac stimulation; not fully established.
What to do
Avoid pseudoephedrine in patients with QT risk factors on fluphenazine; otherwise monitor blood pressure and heart rhythm.
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 Pseudoephedrine
- Isocarboxazid + Pseudoephedrine Contraindicated
- Phenelzine + Pseudoephedrine Contraindicated
- Pseudoephedrine + Rasagiline Contraindicated
- Pseudoephedrine + Selegiline Contraindicated
- Pseudoephedrine + Selegiline transdermal Contraindicated
- Pseudoephedrine + Tranylcypromine Contraindicated
Other interactions of Fluphenazine
- Arsenic trioxide + Fluphenazine Contraindicated
- Dofetilide + Fluphenazine Contraindicated
- Fluphenazine + Ibutilide Contraindicated
- Fluphenazine + Pimozide Contraindicated
- Adagrasib + Fluphenazine Major
- Alfentanil + Fluphenazine Major
Frequently asked questions
Can I take Fluphenazine with Pseudoephedrine?
MediHelp rates the interaction as moderate. Fluphenazine and Pseudoephedrine 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. Phenothiazines can cause QT prolongation and alpha-blockade, while pseudoephedrine stimulates the heart and raises blood pressure. The combination may increase arrhythmia risk in predisposed patients, though evidence is limited.
How serious is the interaction between Fluphenazine and Pseudoephedrine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid pseudoephedrine in patients with QT risk factors on fluphenazine; otherwise monitor blood pressure and heart rhythm.
What other medicines interact with Pseudoephedrine?
MediHelp also lists interactions of Pseudoephedrine with, for example, Isocarboxazid, Phenelzine, Rasagiline. The full list is on the Pseudoephedrine page.
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