Drug & supplement interaction

Pinellia Ternata + Methylnaltrexone

Methylnaltrexone brand name: Relistor.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between Pinellia Ternata and Methylnaltrexone in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the label for Methylnaltrexone states a food rule worth keeping to.

Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Pinellia Ternata and Methylnaltrexone

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Methylnaltrexone and Pinellia Ternata in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Pinellia Ternata safety at a glance

Pinellia Ternata overall Use caution Raw Pinellia is toxic and irritating; only properly processed material used under professional guidance should be considered.
Pregnancy Avoid Traditionally cautioned against and lacking safety data, so it should be avoided in pregnancy.
Breastfeeding Avoid There is not enough safety information, so avoid use while breastfeeding.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Methylnaltrexone and Pinellia Ternata? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Methylnaltrexone

Interactions in our licensed database are recorded against drug classes, not just single drug names. Methylnaltrexone is filed under a single classification — cytochrome p450 2d6 (cyp2d6) inhibitors. Pinellia Ternata has documented interactions with 3 drug classes — the most serious being barbiturates (moderate), benzodiazepines (moderate) and cns depressants (moderate) — and none of Methylnaltrexone’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Pinellia Ternata Does Interact With Other Medications

Pinellia Ternata has 256 moderate known drug interactions in our database — Methylnaltrexone isn’t one of them. If you take anything else, check it against the full list below.

Moderate 256 No known interaction 2,574 (incl. Methylnaltrexone)
Taking anything else?

Check Another of Your Medications Against Pinellia Ternata

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

What to actually watch for

What Pinellia Ternata Itself Has Been Linked To

This is not an interaction — nothing below involves Methylnaltrexone. It is the side-effect record for Pinellia Ternata on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Pinellia Ternata, this list is the first place to look. 3 entries are worth acting on rather than waiting out — marked below.

  • A heart attack / Raised blood pressure Worth acting on Additional detail

    “Pinellia ternata contains ephedrine alkaloids, which may potentially cause hypertension, tachycardia, and heart attack when used orally.”

    Pinellia Ternata · Natural Medicines adverse-effect record, reported in cardiac arrest.

    1 source cited
    1. 12147. FDA, HHS. Final rule declaring dietary supplements containing ephedrine alkaloids adulterated because they present an unreasonable risk. Fed Regist 2004;69:6787-6854.
  • Wheezing Worth acting on Additional detail

    “If Pinellia ternata preparations are inhaled they can cause IgE-mediated occupational asthma.”

    Pinellia Ternata · Natural Medicines adverse-effect record, reported in asthma.

    1 source cited
    1. 12145. Kim SH, Jeong H, Kim YK, et al. IgE-mediated occupational asthma induced by herbal medicine, Bahna (Pinellia ternata). Clin Exp Allergy 2000;31:779-81.
  • Seizures Worth acting on Additional detail

    “Pinellia ternata contains ephedrine alkaloids, which may potentially cause stroke and seizures when used orally.”

    Pinellia Ternata · Natural Medicines adverse-effect record, reported in epilepsy.

    1 source cited
    1. 12147. FDA, HHS. Final rule declaring dietary supplements containing ephedrine alkaloids adulterated because they present an unreasonable risk. Fed Regist 2004;69:6787-6854.
  • A fast or pounding heartbeat Additional detail

    Recorded for Pinellia Ternata in the same Natural Medicines adverse-effect record shown under A heart attack / Raised blood pressure above.

Everything above comes from the Natural Medicines adverse-effect record for Pinellia Ternata — expand a row for the licensed statement it rests on. We read the ADVERSE REACTIONS section of Methylnaltrexone’s FDA label too, and the two lists don’t meaningfully overlap — which is why no Methylnaltrexone column appears here.

How to take them

Some Methylnaltrexone Products Have a Food Rule — Pinellia Ternata Should Not Break It

At least one FDA label for a product containing Methylnaltrexone says to take it on an empty stomach. Most supplements — Pinellia Ternata included — are taken with a meal, so the easy mistake is swallowing both together at breakfast. Where that rule applies, keep Methylnaltrexone on its own and move Pinellia Ternata to a meal later in the day.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Methylnaltrexone products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

o In patients with chronic non-cancer pain and OIC, take RELISTOR tablets with water on an empty stomach at least 30 minutes before the first meal of the day.

From the Dosage and Administration section of the FDA label we read for Methylnaltrexone — where that label names a specific product, the instruction is that product's. See the Methylnaltrexone drug page ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

Everything else you take

See Every Supplement That Interacts With Methylnaltrexone

This page covers Pinellia Ternata only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Methylnaltrexone page lists 3 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Fever Bark (moderate), Iboga (moderate) and Yohimbe (moderate).

By severity: 3 moderate.

From our pharmacist’s overview on the Methylnaltrexone page

“If you take methylnaltrexone (Relistor) for opioid-induced constipation, the supplement list to know is short: three ingredients, all rated moderate, none major. Yohimbe, fever bark, and iboga are all cleared by the same liver enzyme, CYP2D6, and methylnaltrexone can slow that enzyme, letting their active compounds build up in your blood.”

Reviewed by 2 · Jul 18, 2026

Open the Methylnaltrexone interaction page

One more smart check

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

We hold 20 real supplement products containing Pinellia Ternata, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Pinellia Ternata. Even though Pinellia Ternata itself has no known interaction with Methylnaltrexone, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Pinellia Ternata and Methylnaltrexone 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 Pinellia Ternata
Top half

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

29 days ago today
Medication Methylnaltrexone
Steady interest

#2,793 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.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Pinellia Ternata reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Pinellia Ternata and Methylnaltrexone records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Pinellia Ternata

What is Pinellia Ternata?

  • Nausea and vomiting
  • Cough with phlegm
  • Morning sickness (traditional use)
  • Digestive upset and bloating
  • Throat discomfort

Pinellia ternata is a tuber used in traditional Chinese medicine, most often for nausea, vomiting, and phlegmy coughs, and almost always as part of multi-herb formulas. The raw plant is toxic and must be specially processed before use, so it should only be used under qualified guidance. Solid human evidence is limited, and it should be avoided in pregnancy and breastfeeding.

Pinellia ternata · Araceae · Dried tuber (rhizome), usually processed before use · Dried processed tuber, powder, granules, decoctions (teas), and part of multi-herb traditional formulas

An interaction check asks whether these two react with each other — it does not ask whether Pinellia Ternata is a good idea for someone in your situation. Here is what our Pinellia Ternata record says about it on its own.

Pinellia Ternata: dosing

There is no well-established standardized dose of Pinellia ternata for supplement users. In traditional Chinese medicine it is given as processed tuber within specific multi-herb formulas, with the amount and preparation chosen by a trained practitioner.Because the raw herb is toxic and product quality varies, you should not try to dose this herb on your own. If you use a product, follow the label exactly and ideally work with a qualified practitioner.

From our Pinellia Ternata monograph — the full record covers uses, side effects and every documented interaction.

Read the full Pinellia Ternata monograph & all interactions
Medication

About Methylnaltrexone

What Is Methylnaltrexone Used For?

Brand name: Relistor

Methylnaltrexone, sold as Relistor, treats opioid-induced constipation (OIC) — constipation caused by opioid pain medications. Both Relistor tablets and Relistor injection are approved for adults with chronic non-cancer pain, including those with pain related to a prior cancer or its treatment who do not need frequent opioid dose increases.

Relistor injection is also approved for adults with advanced illness or active cancer pain who require increasing opioid doses as part of palliative care.

See full Methylnaltrexone drug information
Keep checking

Other Drugs & Pinellia Ternata

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

0Major
256Moderate
0Minor
2,573No known interaction
256 Moderate 2,573 No interaction
Moderate

256 interactions

Showing 60 of 256 moderate interactions — see all 256 on the Pinellia Ternata page.

No interaction 2,573 drugs checked — show the list

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

Showing the 60 most looked-up of 2,573 medications checked with no known interaction — see the full Pinellia Ternata list.

See the full Pinellia Ternata interactions page
See every supplement checked against Methylnaltrexone, ranked by severity
Evidence & sources

Pinellia Ternata References

The 4 references that drive our Pinellia Ternata monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Kim SH, Jeong H, Kim YK, et al. IgE-mediated occupational asthma induced by herbal medicine, Bahna (Pinellia ternata). Clin Exp Allergy 2000;31:779-81.
  2. FDA, HHS. Final rule declaring dietary supplements containing ephedrine alkaloids adulterated because they present an unreasonable risk. Fed Regist 2004;69:6787-6854.
  3. Lin S, Nie B, Yao G, Yang H, Ye R, Yuan Z. Pinellia ternata (Thunb.) makino preparation promotes sleep by increasing REM sleep. Nat Prod Res. 2019;33(22):3326-3329. PubMed
  4. Lin YH, Chen C, Zhao X, et al. Efficacy and Safety of Banxia Formulae for Insomnia: A Systematic Review and Meta-Analysis of High-Quality Randomized Controlled Trials. Evid Based Complement Alternat Med 2021;2021:8833168. PubMed

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Pinellia Ternata and Methylnaltrexone Together: Common Questions

Is it safe to take Pinellia Ternata with Methylnaltrexone?
We do not list a known interaction between Pinellia Ternata and Methylnaltrexone. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Should I take Pinellia Ternata and Methylnaltrexone at the same time of day?
At least one FDA label for a product containing Methylnaltrexone says to take it on an empty stomach, and supplements are usually taken with a meal — so taking them together at breakfast is the easy mistake. Where that applies, keep Methylnaltrexone on its own and move Pinellia Ternata to a meal later in the day. Food instructions belong to the product rather than the ingredient, so check the directions on your own box. This is about absorption, not an interaction.
How was the Pinellia Ternata and Methylnaltrexone combination checked?
Interactions in our licensed database are recorded against drug classes. Methylnaltrexone is filed under 1 classification, and Pinellia Ternata has documented interactions with 3 drug classes — none of Methylnaltrexone's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Pinellia Ternata interact with any other medications?
Yes. Pinellia Ternata has 256 documented drug interactions in our database — Methylnaltrexone is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Methylnaltrexone interact with any supplements?
Yes. Methylnaltrexone has documented interactions with 3 supplements in our database — Pinellia Ternata is not one of them. The Methylnaltrexone interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Pinellia Ternata monograph Uses, safety profile, and every drug interaction in one place Methylnaltrexone drug information The full plain-English guide to this medication Methylnaltrexone supplement interactions Every supplement checked against Methylnaltrexone, 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 References The 4 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Methylnaltrexone and Pinellia Ternata?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.