Drug interactions
Fosphenytoin + Hydrocodone
Severity: Moderate
Fosphenytoin and Hydrocodone: 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
Fosphenytoin (phenytoin) induces CYP3A4 and can lower hydrocodone levels, leading to reduced analgesia. If it is stopped, hydrocodone levels may rise and cause respiratory depression.
What this interaction means in plain words
Fosphenytoin and Hydrocodone 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.
Fosphenytoin belongs to Central Nervous System; Hydrocodone belongs to Musculoskeletal.
Why it happens
Induction of CYP3A4 increasing hydrocodone clearance.
What to do
Monitor analgesic effect and adjust hydrocodone dose. Reduce the dose and monitor for respiratory depression after fosphenytoin discontinuation.
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 Hydrocodone
- Alvimopan + Hydrocodone Contraindicated
- Bupropion-naltrexone + Hydrocodone Contraindicated
- Hydrocodone + Isocarboxazid Contraindicated
- Hydrocodone + Olanzapine / samidorphan Contraindicated
- Hydrocodone + Phenelzine Contraindicated
- Alfentanil + Hydrocodone Major
Other interactions of Fosphenytoin
- Dronedarone + Fosphenytoin Contraindicated
- Fosphenytoin + Ledipasvir-sofosbuvir Contraindicated
- Fosphenytoin + Lorlatinib Contraindicated
- Fosphenytoin + Lurasidone Contraindicated
- Fosphenytoin + Ranolazine Contraindicated
- Fosphenytoin + Sofosbuvir-velpatasvir-voxilaprevir Contraindicated
Frequently asked questions
Can I take Fosphenytoin with Hydrocodone?
MediHelp rates the interaction as moderate. Fosphenytoin and Hydrocodone 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. Fosphenytoin (phenytoin) induces CYP3A4 and can lower hydrocodone levels, leading to reduced analgesia. If it is stopped, hydrocodone levels may rise and cause respiratory depression.
How serious is the interaction between Fosphenytoin and Hydrocodone?
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 effect and adjust hydrocodone dose. Reduce the dose and monitor for respiratory depression after fosphenytoin discontinuation.
What other medicines interact with Hydrocodone?
MediHelp also lists interactions of Hydrocodone with, for example, Alvimopan, Bupropion-naltrexone, Isocarboxazid. The full list is on the Hydrocodone page.
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