Drug interactions
Dextroamphetamine + Phenylephrine
Severity: Moderate
Dextroamphetamine and Phenylephrine: 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 raise blood pressure through adrenergic stimulation. Together they can cause marked hypertension, tachycardia or arrhythmia, particularly in patients with cardiovascular disease.
What this interaction means in plain words
Dextroamphetamine and Phenylephrine 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.
Dextroamphetamine belongs to Central Nervous System; Phenylephrine belongs to Respiratory.
Why it happens
Additive sympathomimetic effects: amphetamine releases norepinephrine while phenylephrine directly stimulates alpha-1 receptors.
What to do
Monitor blood pressure and heart rate, especially with systemic phenylephrine. Avoid oral decongestant use in patients with hypertension or heart disease taking amphetamines.
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 Phenylephrine
- Isocarboxazid + Phenylephrine Contraindicated
- Phenelzine + Phenylephrine Contraindicated
- Phenylephrine + Tranylcypromine Contraindicated
- Bromocriptine + Phenylephrine Major
- Cocaine + Phenylephrine Major
- Dihydroergotamine intranasal + Phenylephrine Major
Other interactions of Dextroamphetamine
- Dextroamphetamine + Isocarboxazid Contraindicated
- Dextroamphetamine + Linezolid Contraindicated
- Dextroamphetamine + Methylene blue Contraindicated
- Dextroamphetamine + Phenelzine Contraindicated
- Dextroamphetamine + Rasagiline Contraindicated
- Dextroamphetamine + Safinamide Contraindicated
Frequently asked questions
Can I take Dextroamphetamine with Phenylephrine?
MediHelp rates the interaction as moderate. Dextroamphetamine and Phenylephrine 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 raise blood pressure through adrenergic stimulation. Together they can cause marked hypertension, tachycardia or arrhythmia, particularly in patients with cardiovascular disease.
How serious is the interaction between Dextroamphetamine and Phenylephrine?
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 blood pressure and heart rate, especially with systemic phenylephrine. Avoid oral decongestant use in patients with hypertension or heart disease taking amphetamines.
What other medicines interact with Phenylephrine?
MediHelp also lists interactions of Phenylephrine with, for example, Isocarboxazid, Phenelzine, Tranylcypromine. The full list is on the Phenylephrine page.
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