Drug interactions
Hydralazine + Phenylephrine po
Severity: Moderate
Hydralazine and Phenylephrine po: 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
Oral phenylephrine, commonly used as a decongestant, is an alpha-agonist that can raise blood pressure. This may reduce the effect of hydralazine and lead to poorer blood pressure control. Effects are usually modest at standard doses.
What this interaction means in plain words
Hydralazine and Phenylephrine po 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
Pharmacodynamic antagonism between alpha-1 agonist vasoconstriction and the direct vasodilating action of hydralazine.
What to do
Check blood pressure in patients using decongestants, and advise hypertensive patients to avoid them where possible. Choose a non-pressor alternative for nasal symptoms if blood pressure rises.
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 Hydralazine
- Amifostine + Hydralazine Major
- Aceclofenac + Hydralazine Moderate
- Acemetacin + Hydralazine Moderate
- Aldesleukin + Hydralazine Moderate
- Avanafil + Hydralazine Moderate
- Benzphetamine + Hydralazine Moderate
Frequently asked questions
Can I take Hydralazine with Phenylephrine po?
MediHelp rates the interaction as moderate. Hydralazine and Phenylephrine po 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. Oral phenylephrine, commonly used as a decongestant, is an alpha-agonist that can raise blood pressure. This may reduce the effect of hydralazine and lead to poorer blood pressure control. Effects are usually modest at standard doses.
How serious is the interaction between Hydralazine and Phenylephrine po?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Check blood pressure in patients using decongestants, and advise hypertensive patients to avoid them where possible. Choose a non-pressor alternative for nasal symptoms if blood pressure rises.
What other medicines interact with Hydralazine?
MediHelp also lists interactions of Hydralazine with, for example, Amifostine, Aceclofenac, Acemetacin. The full list is on the Hydralazine page.
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