Lisdexamfetamine and Omeprazole: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 2, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Lisdexamfetamine
Omeprazole
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
Here's what's going on. Vyvanse (lisdexamfetamine) turns into amphetamine in your body. Amphetamine leaves your body through your urine, and how fast it leaves depends on how acidic or alkaline that urine is. Medicines like omeprazole (Prilosec) can make your urine more alkaline, which can slow down how quickly amphetamine is cleared.
The result is that amphetamine may build up a bit, so you could feel stronger effects, like a faster heartbeat, jitteriness, trouble sleeping, or higher blood pressure. The good news is this is manageable. Please don't stop either medicine on your own. Just let your pharmacist or doctor know you take both so they can watch how you're doing and adjust if needed.
Mechanism: Amphetamine renal clearance is pH dependent; urinary alkalinization increases reabsorption and prolongs half-life, raising amphetamine exposure. Lisdexamfetamine is a prodrug hydrolyzed to active dextroamphetamine, so higher amphetamine levels mean potentiated sympathomimetic effect.
Direction: increased amphetamine exposure and effect.
Evidence: theoretical; magnitude and onset unspecified. Note the classically cited alkalinizers are systemic agents; omeprazole's urinary pH effect is modest and less established.
- Monitor: blood pressure, heart rate, agitation, insomnia, appetite.
- Management: dose may be individualized; consider closer monitoring; use lowest effective stimulant dose.
What happens
Increased exposure to amphetamine
Interaction Deep Dive
Do not combine amphetamines with agents that alkalize the gastrointestinal tract1 or the urine2, since this combination can raise amphetamine blood concentrations and enhance its effects2. Because amphetamine elimination depends on pH, alkaline urine markedly prolongs its half-life1.
Why it happens (mechanism)
Decreased renal elimination
How to manage this interaction
What your care team may do:
- Keep taking both medicines as prescribed unless your prescriber tells you otherwise.
- Watch you a little more closely for stronger stimulant effects, such as elevated blood pressure, faster heart rate, restlessness, or poor sleep.
- Adjust and individualize your stimulant dose if needed to keep effects comfortable.
What you can do: Tell your pharmacist or doctor that you take both Vyvanse and omeprazole. Report any new jitteriness, racing heart, or sleep trouble. Don't start or stop either medication on your own.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Lisdexamfetamine and Omeprazole together?
Omeprazole can slightly slow how your body clears amphetamine from Vyvanse, which may strengthen its effects, so keep taking both as prescribed but tell your care team so they can monitor you and adjust the dose if needed. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Lisdexamfetamine and Omeprazole interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Lisdexamfetamine and Omeprazole interaction managed?
What your care team may do: Keep taking both medicines as prescribed unless your prescriber tells you otherwise. Watch you a little more closely for stronger stimulant effects, such as elevated blood pressure, faster heart rate, restlessness, or poor sleep. Adjust and individualize your stimulant dose if needed to keep effects comfortable. What you can do: Tell your pharmacist or doctor that you t… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Lisdexamfetamine or Omeprazole need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (2)
- Product Information: Desoxyn(R) oral tablets, methamphetamine HCl oral tablets. Recordati Rare Diseases Inc (per FDA), Lebanon, NJ, 2017.
- Product Information: EVEKEO ODT(TM) orally disintegrating tablets, amphetamine sulfate orally disintegrating tablets. Arbor Pharmaceuticals LLC (per FDA), Atlanta, GA, 2019.
Keep reading about Lisdexamfetamine
Keep reading about Omeprazole
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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