Drug interactions
Phenytoin + Sertraline
Severity: Moderate
Phenytoin and Sertraline: 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
Sertraline may inhibit phenytoin metabolism and raise its serum concentration, with isolated reports of phenytoin toxicity. Because phenytoin has a narrow therapeutic index and nonlinear kinetics, small changes can matter.
What this interaction means in plain words
Phenytoin and Sertraline 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.
Phenytoin belongs to Central Nervous System; Sertraline belongs to Central Nervous System.
Why it happens
Inhibition of CYP2C9/2C19-mediated phenytoin metabolism by sertraline.
What to do
Monitor serum phenytoin levels and signs of toxicity such as nystagmus, ataxia and confusion after starting or changing sertraline. Reduce the phenytoin dose if levels rise.
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 Sertraline
- Isocarboxazid + Sertraline Contraindicated
- Methylene blue + Sertraline Contraindicated
- Phenelzine + Sertraline Contraindicated
- Pimozide + Sertraline Contraindicated
- Selegiline transdermal + Sertraline Contraindicated
- Selegiline + Sertraline Contraindicated
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 Sertraline?
MediHelp rates the interaction as moderate. Phenytoin and Sertraline 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. Sertraline may inhibit phenytoin metabolism and raise its serum concentration, with isolated reports of phenytoin toxicity. Because phenytoin has a narrow therapeutic index and nonlinear kinetics, small changes can matter.
How serious is the interaction between Phenytoin and Sertraline?
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 serum phenytoin levels and signs of toxicity such as nystagmus, ataxia and confusion after starting or changing sertraline. Reduce the phenytoin dose if levels rise.
What other medicines interact with Sertraline?
MediHelp also lists interactions of Sertraline with, for example, Isocarboxazid, Methylene blue, Phenelzine. The full list is on the Sertraline page.
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