Drug Interaction Report

Isradipine and Tacrolimus: Interaction Details

Name: Isradipine and Tacrolimus Interaction
Creator: Dr. Brian Staiger, PharmD, BCPS

A pharmacist-reviewed analysis of the Isradipine and Tacrolimus interaction: the documented clinical effects, severity rating, onset, mechanism, and management considerations, with cited references throughout.

AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Tacrolimus

Astagraf Astagraf XL® Envarsus Envarsus XR® Prograf Prograf®

Isradipine

DynaCirc® DynaCirc® CR

Medically reviewed by

Dr. Brian Staiger, PharmD, BCPS

Updated Aug 8, 2026

Editorial policy · Data sources

Interaction severity

Major

Potentially serious — often needs a change or close monitoring.

Minor

Moderate

Major

Contraindicated

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.

Of 113 documented Isradipine interactions, 96 are rated major — including this one.

Worried about symptoms right now? Contact your pharmacist or prescriber, or call Poison Control at 1-800-222-1222 (US). Call 911 for an emergency.

Onset

unspecified

Evidence

theoretical

Severity

Major

What happens

Increased tacrolimus exposure

Interaction Deep Dive

Concomitant use of tacrolimus with calcium channel blockers may increase tacrolimus blood concentrations. Consider reducing the tacrolimus dosage in case of concomitant use¹².

Why it happens (mechanism)

Unknown

Common questions

Can I take Isradipine and Tacrolimus together?

Increased tacrolimus exposure Always confirm with your pharmacist or prescriber before making any change.

How serious is the Isradipine and Tacrolimus 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 strong is the evidence for this interaction?

The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.

Questions for your pharmacist

Does my dose of Isradipine or Tacrolimus 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: ENVARSUS XR(R) oral extended-release tablets, tacrolimus oral extended-release tablets. Veloxis Pharmaceuticals Inc (per FDA), Cary, NC, 2023. DailyMed
Product Information: PROGRAF(R) oral capsules, oral granules for suspension, intravenous injection, tacrolimus oral capsules, oral granules for suspension, intravenous injection. Astellas Pharma US Inc (per FDA), Northbrook, IL, 2023. DailyMed

Was this write-up helpful?

Tacrolimus

Keep reading about Tacrolimus

All Tacrolimus interactions (157) Tacrolimus drug information

Also serious with: Ketoconazole Topical Lefamulin Lenacapavir Injection Perindopril

Isradipine

Keep reading about Isradipine

All Isradipine interactions (113) Isradipine drug information

Also serious with: Mefloquine Dolasetron Injection Disopyramide Octreotide Injection

Beyond drug–drug

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:

Tacrolimus + Activated Charcoal American Hellebore Arsenic Asarabacca Cesium Ephedra Grapefruit Siberian Cocklebur + 194 more

Isradipine + Activated Charcoal American Hellebore American Mistletoe Arsenic Cesium Coleus Ephedra Grapefruit + 231 more

major · moderate · minor — check everything you take with our drug–supplement interaction checker.

Check another combination

Our instant two-drug interaction checker is almost here.

Coming soon

The instant two-drug checker is on its way.

In the meantime, browse the directory below to look up any drug and see its documented interactions.

Still have questions about this combination?

Every question gets a real answer from a licensed pharmacist — free, and usually within a day.

Ask the pharmacist

A message from HelloPharmacist

About our interaction database: depth, not breadth

HelloPharmacist doesn't license one of the big commercial interaction databases, so what you'll find here is not a complete list of every known drug interaction. Instead, each entry is researched, analyzed, and written up individually — documented from the published literature, reviewed by a pharmacist, and cited so you can check every source yourself.

If a combination isn't listed here, it means we haven't documented it yet — never that it's safe. For screening a full medication list, we recommend pairing this site with a comprehensive tool like the Drugs.com Interaction Checker and, most importantly, a review by your own pharmacist. For a deep, plain-English, fully sourced explanation of a specific documented interaction — that's exactly what we built this for.

This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.