Drug & supplement interaction

Purple Nut Sedge + Disopyramide Phosphate

Disopyramide Phosphate brand names: Norpace CR, Norpace.

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

Purple Nut Sedge has a moderate interaction with Disopyramide Phosphate. In vitro, purple nut sedge dose-dependently inhibits acetylcholinesterase (AChE).

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

Purple Nut Sedge and Disopyramide Phosphate

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

Moderate

ANTICHOLINERGIC DRUGS

Why this applies to Disopyramide Phosphate

Disopyramide Phosphate falls under ANTICHOLINERGIC DRUGS — the group Purple Nut Sedge interacts with.

In vitro, purple nut sedge dose-dependently inhibits acetylcholinesterase (AChE). Theoretically, concurrent use of anticholinergic drugs and purple nut sedge might decrease the effectiveness of purple nut sedge or the anticholinergic agent.
Some anticholinergic drugs include atropine, benztropine (Cogentin), biperiden (Akineton), procyclidine (Kemadrin), and trihexyphenidyl (Artane).
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 short version: disopyramide doesn't just calm irregular heartbeats, it also carries strong anticholinergic activity, which is why people on it often notice dry mouth, blurry vision, constipation, or trouble urinating. Purple nut sedge has shown, in test-tube studies only, that it can block an enzyme called acetylcholinesterase, which tends to push in the opposite direction from anticholinergic drugs.

So in theory, the two could partly cancel each other out, possibly softening disopyramide's effect or that of the herb. I'll be honest with you though, this is based on lab work, not real patients, so we don't truly know if it matters in the body. Because disopyramide is a heart-rhythm medicine with little room for error, please don't combine them without first checking with your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Sharma R, Gupta R. Cyperus rotundus extract inhibits acetylcholinesterase activity from animal and plants as well as inhibits germination and seedling growth in wheat and tomato. Life Sci. 2007;80(24-25):2389-2392. PubMed

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

Purple Nut Sedge Also Interacts With Other Medications

Purple Nut Sedge has 423 moderate known drug interactions in our database — the Disopyramide Phosphate one above is one of them. If you take anything else, check it against the full list below.

Moderate 423 No known interaction 2,407 (incl. Disopyramide Phosphate)
Taking anything else?

Check Another of Your Medications Against Purple Nut Sedge

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

Everything else you take

See Every Supplement That Interacts With Disopyramide Phosphate

This page covers Purple Nut Sedge only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Disopyramide Phosphate page lists 169 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Arsenic (major), Cesium (major) and Ephedra (major).

By severity: 10 major · 117 moderate · 42 minor.

From our pharmacist’s overview on the Disopyramide Phosphate page

“Grapefruit is the first thing I would set aside on disopyramide phosphate (Norpace), a medicine that steadies dangerous heart rhythms, because grapefruit juice can push the drug's blood level up. That pattern dominates the page, since 121 of the 169 flagged ingredients act on the same liver enzyme, CYP3A4, raising the drug's level or,…”

Reviewed by 2 · Jul 18, 2026

Open the Disopyramide Phosphate interaction page

How much people look this up

Where Purple Nut Sedge and Disopyramide Phosphate 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 Purple Nut Sedge
Top half

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

29 days ago today
Medication Disopyramide Phosphate
Steady interest

#1,797 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 Purple Nut Sedge

What is Purple Nut Sedge?

  • Digestive upset and bloating
  • Menstrual cramps and irregular periods
  • Fever and inflammation
  • Skin and weight-related concerns
  • Antimicrobial uses

Purple nut sedge (Cyperus rotundus) is a common weed whose tubers have a long history in Ayurvedic, Chinese, and other traditional medicine systems, mostly for digestive and menstrual complaints. Modern human evidence is very limited, so its benefits remain unproven. If you want to try it, talk with a pharmacist or doctor first, and avoid it during pregnancy and breastfeeding.

Read the full Purple Nut Sedge monograph & all interactions
Medication

About Disopyramide

What Is Disopyramide Used For?

Brand names: Norpace CR, Norpace

Disopyramide — available as Disopyramide Phosphate, Norpace, and Norpace CR — is indicated for the treatment of documented ventricular arrhythmias, such as sustained ventricular tachycardia (a fast, dangerous heart rhythm originating in the lower chambers), that a physician judges to be life-threatening.

Because of its potential to worsen heart rhythm problems, it is generally not recommended for lesser arrhythmias, and it should not be used to treat ventricular premature contractions (extra heartbeats) that cause no symptoms. Treatment is typically started in a hospital setting.

See full Disopyramide drug information
Keep checking

Other Drugs & Purple Nut Sedge

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

0Major
423Moderate
0Minor
2,406No known interaction
423 Moderate 2,406 No interaction
Moderate

423 interactions

Showing 60 of 423 moderate interactions — see all 423 on the Purple Nut Sedge page.

No interaction 2,406 drugs checked — show the list

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

Showing the 60 most looked-up of 2,406 medications checked with no known interaction — see the full Purple Nut Sedge list.

See the full Purple Nut Sedge interactions page
See every supplement checked against Disopyramide Phosphate, 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
Purple Nut Sedge monograph › Uses, safety, and every drug interaction in one place Disopyramide Phosphate supplement interactions › Every supplement checked against Disopyramide Phosphate, ranked by severity Disopyramide 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 Purple Nut Sedge and Disopyramide Phosphate Together: Common Questions

Can you take Purple Nut Sedge with Disopyramide Phosphate?
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 Purple Nut Sedge and Disopyramide Phosphate 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 Disopyramide Phosphate and Purple Nut Sedge?

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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.