Drug interactions
Olanzapine + Phenylephrine po
Severity: Minor
Olanzapine and Phenylephrine po: minor 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 is a mild sympathomimetic decongestant and olanzapine is a sedating antipsychotic, so their effects on alertness oppose each other with an unclear net result. Olanzapine's alpha-1 blockade may blunt the pressor effect of phenylephrine.
What this interaction means in plain words
Olanzapine and Phenylephrine po have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Why it happens
Pharmacodynamic opposition: alpha-1 adrenergic blockade by olanzapine versus alpha-1 agonism by phenylephrine.
What to do
No routine adjustment is needed; short-term decongestant use is acceptable. Monitor blood pressure and heart rate in patients with cardiovascular disease.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Olanzapine
Frequently asked questions
Can I take Olanzapine with Phenylephrine po?
MediHelp rates the interaction as minor. Olanzapine and Phenylephrine po have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Oral phenylephrine is a mild sympathomimetic decongestant and olanzapine is a sedating antipsychotic, so their effects on alertness oppose each other with an unclear net result. Olanzapine's alpha-1 blockade may blunt the pressor effect of phenylephrine.
How serious is the interaction between Olanzapine and Phenylephrine po?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No routine adjustment is needed; short-term decongestant use is acceptable. Monitor blood pressure and heart rate in patients with cardiovascular disease.
What other medicines interact with Olanzapine?
MediHelp also lists interactions of Olanzapine with, for example, Amisulpride, Amoxapine, Apomorphine. The full list is on the Olanzapine page.
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