Drug interactions
Bleomycin + Fosphenytoin
Severity: Moderate
Bleomycin 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
Chemotherapy combinations containing bleomycin have been linked to lower phenytoin concentrations and breakthrough seizures. Phenytoin levels may rebound after chemotherapy ends.
What this interaction means in plain words
Bleomycin 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.
Bleomycin belongs to Oncology; Fosphenytoin belongs to Central Nervous System.
Why it happens
Mechanism is uncertain; reduced phenytoin absorption or increased clearance during cytotoxic therapy has been proposed.
What to do
Monitor phenytoin concentrations (adjusted for albumin) and seizure control during and after chemotherapy. Adjust fosphenytoin dose accordingly.
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 Bleomycin
- Adenovirus types 4 and 7 live + Bleomycin Contraindicated
- Bleomycin + Brentuximab Contraindicated
- Bleomycin + Brentuximab vedotin Contraindicated
- Bleomycin + Dengue vaccine Major
- Bleomycin + Trastuzumab deruxtecan Major
- Bleomycin + Cholera vaccine Moderate
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 Bleomycin with Fosphenytoin?
MediHelp rates the interaction as moderate. Bleomycin 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. Chemotherapy combinations containing bleomycin have been linked to lower phenytoin concentrations and breakthrough seizures. Phenytoin levels may rebound after chemotherapy ends.
How serious is the interaction between Bleomycin 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 concentrations (adjusted for albumin) and seizure control during and after chemotherapy. Adjust fosphenytoin dose accordingly.
What other medicines interact with Bleomycin?
MediHelp also lists interactions of Bleomycin with, for example, Adenovirus types 4 and 7 live, Brentuximab, Brentuximab vedotin. The full list is on the Bleomycin page.
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