Drug interactions
Fosphenytoin + Ledipasvir-sofosbuvir
Severity: Contraindicated
Fosphenytoin and Ledipasvir-sofosbuvir: contraindicated 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 is converted to phenytoin, a potent inducer of intestinal P-glycoprotein and other enzymes, which can substantially lower sofosbuvir and ledipasvir exposure. This may lead to loss of antiviral efficacy and hepatitis C treatment failure or resistance.
What this interaction means in plain words
Fosphenytoin and Ledipasvir-sofosbuvir are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two.
Fosphenytoin belongs to Central Nervous System; Ledipasvir-sofosbuvir belongs to Anti Virals.
Why it happens
Phenytoin induces intestinal P-glycoprotein, reducing absorption and plasma concentrations of sofosbuvir and ledipasvir.
What to do
Do not co-administer. Switch to a non-inducing antiepileptic such as levetiracetam before starting the hepatitis C regimen, under neurology guidance.
What to ask your pharmacist
- Is there an alternative to one of these two medicines for me?
- If both are essential, who is monitoring me and how often?
- Which symptoms mean I should stop and seek help straight away?
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Other interactions of Ledipasvir-sofosbuvir
- Ledipasvir-sofosbuvir + Phenobarbital Contraindicated
- Ledipasvir-sofosbuvir + Phenytoin Contraindicated
- Ledipasvir-sofosbuvir + Rifampin Contraindicated
- Ledipasvir-sofosbuvir + Rifapentine Contraindicated
- Ledipasvir-sofosbuvir + St john's wort Contraindicated
- Ledipasvir-sofosbuvir + Tipranavir Contraindicated
Other interactions of Fosphenytoin
- Dronedarone + Fosphenytoin Contraindicated
- Fosphenytoin + Lorlatinib Contraindicated
- Fosphenytoin + Lurasidone Contraindicated
- Fosphenytoin + Ranolazine Contraindicated
- Fosphenytoin + Sofosbuvir-velpatasvir-voxilaprevir Contraindicated
- Abiraterone + Fosphenytoin Major
Frequently asked questions
Can I take Fosphenytoin with Ledipasvir-sofosbuvir?
MediHelp rates the interaction as contraindicated. Fosphenytoin and Ledipasvir-sofosbuvir are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two. Fosphenytoin is converted to phenytoin, a potent inducer of intestinal P-glycoprotein and other enzymes, which can substantially lower sofosbuvir and ledipasvir exposure. This may lead to loss of antiviral efficacy and hepatitis C treatment failure or resistance.
How serious is the interaction between Fosphenytoin and Ledipasvir-sofosbuvir?
MediHelp rates it contraindicated, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Do not co-administer. Switch to a non-inducing antiepileptic such as levetiracetam before starting the hepatitis C regimen, under neurology guidance.
What other medicines interact with Ledipasvir-sofosbuvir?
MediHelp also lists interactions of Ledipasvir-sofosbuvir with, for example, Phenobarbital, Phenytoin, Rifampin. The full list is on the Ledipasvir-sofosbuvir page.
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