Drug interactions
Carboplatin + Fosphenytoin
Severity: Moderate
Carboplatin 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
Platinum chemotherapy has been reported to lower serum phenytoin concentrations, which may lead to loss of seizure control. Fosphenytoin is converted to phenytoin, so the same concern applies.
What this interaction means in plain words
Carboplatin 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.
Carboplatin belongs to Oncology; Fosphenytoin belongs to Central Nervous System.
Why it happens
Mechanism is not firmly established; reduced phenytoin absorption or increased clearance has been suggested.
What to do
Monitor free or total phenytoin concentrations during and after chemotherapy cycles and adjust the dose accordingly. Watch for breakthrough seizures.
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 Carboplatin
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 Carboplatin with Fosphenytoin?
MediHelp rates the interaction as moderate. Carboplatin 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. Platinum chemotherapy has been reported to lower serum phenytoin concentrations, which may lead to loss of seizure control. Fosphenytoin is converted to phenytoin, so the same concern applies.
How serious is the interaction between Carboplatin 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 free or total phenytoin concentrations during and after chemotherapy cycles and adjust the dose accordingly. Watch for breakthrough seizures.
What other medicines interact with Carboplatin?
MediHelp also lists interactions of Carboplatin with, for example, Adenovirus types 4 and 7 live, Amikacin, Amphotericin b deoxycholate. The full list is on the Carboplatin page.
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