Drug interactions
Dutasteride-tamsulosin + Phenytoin
Severity: Moderate
Dutasteride-tamsulosin and Phenytoin: 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
Phenytoin induces CYP3A4 and may reduce tamsulosin and dutasteride concentrations. Symptom control may worsen.
What this interaction means in plain words
Dutasteride-tamsulosin and Phenytoin 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.
Dutasteride-tamsulosin belongs to Genitourinary; Phenytoin belongs to Central Nervous System.
Why it happens
CYP3A4 induction increases the metabolism of tamsulosin and dutasteride.
What to do
Monitor urinary symptoms and consider dose or therapy adjustment if response declines.
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 Dutasteride-tamsulosin
Other interactions of Phenytoin
- Artemether / lumefantrine + Phenytoin Contraindicated
- Bictegravir + Phenytoin Contraindicated
- Cabotegravir + Phenytoin Contraindicated
- Doravirine + Phenytoin Contraindicated
- Elbasvir / grazoprevir + Phenytoin Contraindicated
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Phenytoin Contraindicated
Frequently asked questions
Can I take Dutasteride-tamsulosin with Phenytoin?
MediHelp rates the interaction as moderate. Dutasteride-tamsulosin and Phenytoin 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. Phenytoin induces CYP3A4 and may reduce tamsulosin and dutasteride concentrations. Symptom control may worsen.
How serious is the interaction between Dutasteride-tamsulosin and Phenytoin?
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 urinary symptoms and consider dose or therapy adjustment if response declines.
What other medicines interact with Dutasteride-tamsulosin?
MediHelp also lists interactions of Dutasteride-tamsulosin with, for example, Alfuzosin, Amifostine, Atazanavir. The full list is on the Dutasteride-tamsulosin page.
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