Drug & supplement interaction

Adrafinil + Amlodipine Besilate

Amlodipine Besilate brand name: Istin.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Amlodipine Besilate falls into 2 drug categories that Adrafinil can interact with; the most serious is rated moderate. Theoretically, adrafinil might reduce the effects of antihypertensive drugs.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Adrafinil and Amlodipine Besilate

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Adrafinil interacts with whole categories of medication. Amlodipine Besilate falls into 2 of those categories, so it can interact with Adrafinil in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

ANTIHYPERTENSIVE DRUGS

1 of 2

Why this applies to Amlodipine Besilate

Amlodipine Besilate falls under ANTIHYPERTENSIVE DRUGS — the group Adrafinil interacts with.

Theoretically, adrafinil might reduce the effects of antihypertensive drugs.
Adrafinil is a precursor to the stimulant prescription drug modafinil. Modafinil has been shown to increase diastolic and systolic blood pressure. Retrospective analyses show that patients taking modafinil had a small but increased rate of requiring new antihypertensive drugs or increased use of antihypertensive drugs when compared with placebo.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the simple version. Amlodipine is a calcium channel blocker that relaxes your blood vessels to bring your blood pressure down. Adrafinil, on the other hand, turns into modafinil in your body, and modafinil can nudge blood pressure (both the top and bottom numbers) up in some people. So the two are pulling in opposite directions, and the concern is that adrafinil could work against your amlodipine and leave your pressure higher than you'd like.

I'll be honest with you: this is a theoretical concern based on how these drugs behave, not strong proof. For many folks it may be a small effect. Still, if you use a home blood pressure cuff, keep an eye on your readings, and please check in with your pharmacist or doctor before pairing these.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Provigil (modafinil) [package insert]. North Wales, PA: Teva Pharmaceuticals USA, Inc. Published: January 2015. Accessed on: Nov 11, 2022.
Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

2 of 2

Amlodipine Besilate also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

Theoretically, adrafanil might reduce levels and clinical effects of CYP3A4 substrates.
Adrafinil is a precursor to the stimulant prescription drug modafinil. Modafinil has been shown to weakly induce CYP3A4 activity.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the gist for amlodipine, your blood pressure medication. Your liver uses an enzyme called CYP3A4 to break down amlodipine. Adrafinil turns into modafinil in your body, and modafinil can gently speed up that same enzyme. In theory, that could clear amlodipine a little faster, leaving slightly less of it working to relax your blood vessels.

What that might look like in real life is blood pressure creeping back up, since amlodipine may not be pulling its full weight. I want to be honest though: this is a theoretical concern based on how the drugs work, not strong real-world data, and modafinil is only a weak booster of this enzyme. Still, please loop in your doctor or pharmacist before combining them so they can keep an eye on your readings.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Urban AE, Cubala WJ. The role of eugeroics in the treatment of affective disorders. Psychiatr Pol. 2020;54(1):21-33. PubMed
  2. Provigil (modafinil) [package insert]. North Wales, PA: Teva Pharmaceuticals USA, Inc. Published: January 2015. Accessed on: Nov 11, 2022.

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Adrafinil Also Interacts With Other Medications

Adrafinil has 1 major, 1,055 moderate known drug interactions in our database — the Amlodipine Besilate one above is among them. If you take anything else, check it against the full list below.

Major 1 Moderate 1,055 No known interaction 1,774 (incl. Amlodipine Besilate)
Taking anything else?

Check Another of Your Medications Against Adrafinil

Covers the 2,830 medications we’ve checked against Adrafinil. Pick one to open its full report.

Everything else you take

See Every Supplement That Interacts With Amlodipine Besilate

This page covers Adrafinil only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Amlodipine Besilate page lists 232 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Coleus (major) and Grapefruit (major).

By severity: 7 major · 183 moderate · 42 minor.

From our pharmacist’s overview on the Amlodipine Besilate page

“People take amlodipine besilate (Istin) to lower blood pressure, then reach for fish oil, CBD, or a morning glass of grapefruit juice without a second thought, and this is a list that deserves genuine care. Seven of its 232 supplement interactions are rated major, with grapefruit the everyday standout because it blocks the enzyme (CYP3…”

Reviewed by 2 · Jul 18, 2026

Open the Amlodipine Besilate interaction page

One more smart check

Taking Adrafinil as Part of a Dietary Supplement Product? Check It for Interactions

We hold 7 real supplement products containing Adrafinil, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Adrafinil. Your product may carry other ingredients that interact with Amlodipine Besilate too, on top of Adrafinil — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Adrafinil and Amlodipine Besilate Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Adrafinil
Top half

#539 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Amlodipine Besilate
Top 5%

#80 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Supplement

About Adrafinil

What is Adrafinil?

Adrafinil
  • Wakefulness and alertness
  • Fatigue
  • Focus and concentration
  • Cognitive enhancement (nootropic)
  • Daytime sleepiness

Adrafinil is a synthetic compound that the body converts into modafinil, a prescription wakefulness-promoting drug. It is sometimes sold as a nootropic supplement, but it is unregulated, carries real risks (especially to the liver), and is banned in some sports and countries. Talk with a doctor or pharmacist before using it.

Read the full Adrafinil monograph & all interactions
Keep checking

Other Drugs & Adrafinil

Browse every other medication we’ve checked against Adrafinil — both the ones with a known interaction and the ones without. Select any drug for the full detail.

1Major
1,055Moderate
0Minor
1,773No known interaction
1 Major 1,055 Moderate 1,773 No interaction
Major

1 interaction

Moderate

1,055 interactions

Showing 60 of 1,055 moderate interactions — see all 1,055 on the Adrafinil page.

No interaction 1,773 drugs checked — show the list

We also checked Adrafinil against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 1,773 medications checked with no known interaction — see the full Adrafinil list.

See the full Adrafinil interactions page
See every supplement checked against Amlodipine Besilate, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Adrafinil monograph › Uses, safety, and every drug interaction in one place Amlodipine Besilate supplement interactions › Every supplement checked against Amlodipine Besilate, ranked by severity Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Adrafinil and Amlodipine Besilate Together: Common Questions

Can you take Adrafinil with Amlodipine Besilate?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
Why are there 2 interactions listed for Adrafinil and Amlodipine Besilate?
Amlodipine Besilate belongs to more than one drug category, and Adrafinil interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Adrafinil and Amlodipine Besilate interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Amlodipine Besilate and Adrafinil?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.