Drug interactions
Phenytoin + Tramadol
Severity: Moderate
Phenytoin and Tramadol: 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 CYP2B6, which can lower tramadol and active metabolite exposure and lessen pain relief. Tramadol can also provoke seizures, which may be harder to judge in patients taking an anticonvulsant.
What this interaction means in plain words
Phenytoin and Tramadol 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 belongs to Central Nervous System; Tramadol belongs to Musculoskeletal.
Why it happens
Phenytoin enzyme induction increases tramadol metabolism.
What to do
Monitor analgesic response and titrate tramadol upward if needed. Watch seizure control, and reassess the dose if phenytoin is stopped.
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 Tramadol
- Isocarboxazid + Tramadol Contraindicated
- Olanzapine / samidorphan + Tramadol Contraindicated
- Phenelzine + Tramadol Contraindicated
- Procarbazine + Tramadol Contraindicated
- Rasagiline + Tramadol Contraindicated
- Safinamide + Tramadol Contraindicated
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 Phenytoin with Tramadol?
MediHelp rates the interaction as moderate. Phenytoin and Tramadol 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 CYP2B6, which can lower tramadol and active metabolite exposure and lessen pain relief. Tramadol can also provoke seizures, which may be harder to judge in patients taking an anticonvulsant.
How serious is the interaction between Phenytoin and Tramadol?
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 analgesic response and titrate tramadol upward if needed. Watch seizure control, and reassess the dose if phenytoin is stopped.
What other medicines interact with Tramadol?
MediHelp also lists interactions of Tramadol with, for example, Isocarboxazid, Olanzapine / samidorphan, Phenelzine. The full list is on the Tramadol page.
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