Drug interactions
Cisplatin + Fosphenytoin
Severity: Moderate
Cisplatin and Fosphenytoin: 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
Cisplatin-containing chemotherapy has been reported to lower serum phenytoin concentrations, which can result in breakthrough seizures. Fosphenytoin is converted to phenytoin, so the same concern applies.
What this interaction means in plain words
Cisplatin and Fosphenytoin 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.
Cisplatin belongs to Oncology; Fosphenytoin belongs to Central Nervous System.
Why it happens
Not fully established; possibly decreased absorption, increased clearance or altered protein binding of phenytoin.
What to do
Monitor phenytoin levels (preferably free levels) and seizure activity during and after cisplatin cycles, adjusting the dose as required.
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 Cisplatin
- Cidofovir + Cisplatin Contraindicated
- Adefovir + Cisplatin Major
- Adenovirus types 4 and 7 live + Cisplatin Major
- Amikacin + Cisplatin Major
- Amphotericin b deoxycholate + Cisplatin Major
- Amphotericin b + Cisplatin 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 Cisplatin with Fosphenytoin?
MediHelp rates the interaction as moderate. Cisplatin and Fosphenytoin 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. Cisplatin-containing chemotherapy has been reported to lower serum phenytoin concentrations, which can result in breakthrough seizures. Fosphenytoin is converted to phenytoin, so the same concern applies.
How serious is the interaction between Cisplatin and Fosphenytoin?
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 phenytoin levels (preferably free levels) and seizure activity during and after cisplatin cycles, adjusting the dose as required.
What other medicines interact with Cisplatin?
MediHelp also lists interactions of Cisplatin with, for example, Cidofovir, Adefovir, Adenovirus types 4 and 7 live. The full list is on the Cisplatin page.
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