Drug interactions
Phenytoin + Praziquantel
Severity: Major
Phenytoin and Praziquantel: major 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
Phenytoin strongly induces CYP3A4 and other enzymes, markedly reducing praziquantel plasma concentrations. This can cause anthelmintic treatment failure, notably in neurocysticercosis.
What this interaction means in plain words
Phenytoin and Praziquantel can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Phenytoin belongs to Central Nervous System; Praziquantel belongs to Anti Parasitic.
Why it happens
Phenytoin induces CYP3A4 and other metabolic enzymes, accelerating praziquantel clearance.
What to do
Avoid concurrent use if possible, switching to a non-inducing antiseizure agent during treatment. If unavoidable, monitor therapeutic response and consider dose escalation of praziquantel with specialist input.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Praziquantel
- Enzalutamide + Praziquantel Contraindicated
- Praziquantel + Rifampin Contraindicated
- Amobarbital + Praziquantel Major
- Apalutamide + Praziquantel Major
- Butabarbital + Praziquantel Major
- Butalbital + Praziquantel Major
Other interactions of Phenytoin
- Artemether / lumefantrine + Phenytoin Contraindicated
- Bictegravir + Phenytoin Contraindicated
- Cabotegravir + Phenytoin Contraindicated
- Doravirine + Phenytoin Contraindicated
- Elbasvir / grazoprevir + Phenytoin Contraindicated
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Phenytoin Contraindicated
Frequently asked questions
Can I take Phenytoin with Praziquantel?
MediHelp rates the interaction as major. Phenytoin and Praziquantel can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Phenytoin strongly induces CYP3A4 and other enzymes, markedly reducing praziquantel plasma concentrations. This can cause anthelmintic treatment failure, notably in neurocysticercosis.
How serious is the interaction between Phenytoin and Praziquantel?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid concurrent use if possible, switching to a non-inducing antiseizure agent during treatment. If unavoidable, monitor therapeutic response and consider dose escalation of praziquantel with specialist input.
What other medicines interact with Praziquantel?
MediHelp also lists interactions of Praziquantel with, for example, Enzalutamide, Rifampin, Amobarbital. The full list is on the Praziquantel page.
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