Drug & supplement interaction

Sweet Annie + Diltiazem

Diltiazem brand names: Cardizem, Cardizem SR, Diltiaz SR, Cardizem CD, Tiazac, and others.

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

Sweet Annie has a moderate interaction with Diltiazem. Sweet Annie may alter plasma levels and clinical effects of drugs metabolized by CYP3A4.

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

Sweet Annie and Diltiazem

Here is the interaction we found between these two, with the evidence behind it.

Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

Why this applies to Diltiazem

Diltiazem falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group Sweet Annie interacts with.

Sweet Annie may alter plasma levels and clinical effects of drugs metabolized by CYP3A4.
In vitro research shows that the Sweet Annie constituent artemisinin induces CYP3A4, possibly increasing CYP3A4 activity by 1.9-fold. However, Sweet Annie extract seems to inhibit the activity of CYP3A4 in vitro, suggesting that other constituents of Sweet Annie play a role in its effects on the overall activity of this enzyme. More information is needed to determine whether taking Sweet Annie extract affects the metabolism of CYP3A4 substrates.
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 situation with Sweet Annie and your diltiazem. Diltiazem is processed by a liver enzyme called CYP3A4, and Sweet Annie can tug on that enzyme in two opposite directions. One of its compounds (artemisinin) may speed the enzyme up, which could clear diltiazem faster and weaken it, possibly letting your blood pressure or chest pain creep back. But the whole-plant extract seems to slow the enzyme down, which could let diltiazem build up and bring more dizziness, flushing, swollen ankles, or a slow heartbeat.

The honest part: this is based only on lab studies, not real people, so we can't say which way it tips in you. I wouldn't lose sleep over it, but please check with your pharmacist or doctor before pairing them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Xing J, Kirby BJ, Whittington D, et al. Evaluation of P450 inhibition and induction by artemisinin antimalarials in human liver microsomes and primary human hepatocytes. Drug Metabl Dispos 2012;40(9):1757-64. PubMed
  2. Kane NF, Kiani BH, Desrosiers MR, Towler MJ, Weathers PJ. Artemisia extracts differ from artemisinin effects on human hepatic CYP450s 2B6 and 3A4 in vitro. J Ethnopharmacol 2022. DOI

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

Sweet Annie Also Interacts With Other Medications

Sweet Annie has 888 moderate known drug interactions in our database — the Diltiazem one above is one of them. If you take anything else, check it against the full list below.

Moderate 888 No known interaction 1,942 (incl. Diltiazem)
Taking anything else?

Check Another of Your Medications Against Sweet Annie

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

From our Q&A

Questions About Sweet Annie or Diltiazem

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Sweet Annie or Diltiazem, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Diltiazem

This page covers Sweet Annie only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Diltiazem page lists 260 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 · 214 moderate · 39 minor.

From our pharmacist’s overview on the Diltiazem page

“Someone on diltiazem (Cardizem, Tiazac) is usually managing blood pressure, angina, or a fast heart rhythm, so this list deserves genuine care. Seven of the 260 ingredients on file carry a major rating, and two of those are things people actually buy: grapefruit, which blocks the enzyme that clears diltiazem and can push its blood leve…”

Reviewed by 2 · Jul 18, 2026

Open the Diltiazem interaction page

One more smart check

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

We hold 243 real supplement products containing Sweet Annie, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Sweet Annie. Your product may carry other ingredients that interact with Diltiazem too, on top of Sweet Annie — 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 Sweet Annie and Diltiazem 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 Sweet Annie
Steady interest

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

29 days ago today
Medication Diltiazem
Top 25%

#288 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 Sweet Annie

What is Sweet Annie?

Sweet Annie
  • Malaria (traditional)
  • Fever
  • Inflammation
  • Digestive complaints
  • Antimicrobial support
  • Insect repellent

Sweet Annie (Artemisia annua) is the source of artemisinin, a compound used in prescription antimalarial drugs. While the purified drug is well studied for malaria, the herb itself as a supplement is not proven for the wide range of conditions people use it for, and self-treating malaria with the raw herb is dangerous. Talk to a pharmacist or doctor before using it.

Read the full Sweet Annie monograph & all interactions
Medication

About Diltiazem

What Is Diltiazem Used For?

Brand names: Cardizem, Cardizem SR, Diltiaz SR, Cardizem CD, Tiazac, Diltiaz XT, Diltiaz CD, Dilacor, Diltiaz, Cardizem LA, Dilacor XR, Cartia XT, Tiamate, Adizem-SR, Adizem-XL, Angitil SR, Angitil XL, Calcicard CR, Dilcardia SR, Dilzem SR, Dilzem XL, Slozem, Tildiem LA, Tildiem Retard, Viazem XL, Zemtard 120XL, Zemtard 180XL, Zemtard 240XL, Zemtard 300XL

Oral extended-release forms of diltiazem — including Matzim LA, Cardizem LA, Cartia, Cartia XT, Tiadylt ER, and various generic capsules and tablets — are used to treat high blood pressure (hypertension) and chronic stable angina (chest pain brought on by activity). Some capsule formulations, including Cartia, Cartia XT, and certain generics, are also approved for angina due to coronary artery spasm (sudden chest pain caused by a sudden tightening of a coronary artery).

Injectable forms of diltiazem are used in hospital settings to temporarily slow a dangerously fast heart rate in atrial fibrillation or atrial flutter (rapid, irregular heart rhythms), and to restore a normal heart rhythm in paroxysmal supraventricular tachycardia (PSVT) — sudden episodes of a very fast but regular heartbeat originating above the heart's lower chambers.

See full Diltiazem drug information
Keep checking

Other Drugs & Sweet Annie

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

0Major
888Moderate
0Minor
1,941No known interaction
888 Moderate 1,941 No interaction
Moderate

888 interactions

Showing 60 of 888 moderate interactions — see all 888 on the Sweet Annie page.

No interaction 1,941 drugs checked — show the list

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

Showing the 60 most looked-up of 1,941 medications checked with no known interaction — see the full Sweet Annie list.

See the full Sweet Annie interactions page
See every supplement checked against Diltiazem, 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
Sweet Annie monograph › Uses, safety, and every drug interaction in one place Diltiazem supplement interactions › Every supplement checked against Diltiazem, ranked by severity Diltiazem drug information › The full plain-English guide to this medication 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 Sweet Annie and Diltiazem Together: Common Questions

Can you take Sweet Annie with Diltiazem?
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.
How serious is the Sweet Annie and Diltiazem 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 Diltiazem and Sweet Annie?

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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.