Drug & supplement interaction

Arenaria Rubra + Demecarium

Demecarium brand name: Humorsol.

Moderate Interaction
Medically reviewed by · Updated February 2024
The bottom line Moderate

Arenaria Rubra has a moderate interaction with Demecarium. Arenaria rubra, by inhibiting acetylcholinesterase, may theoretically interact with other acetylcholinesterase inhibitors like donepezil and rivastigmine, commonly used in Alzheimer's disease treatment.

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

Arenaria Rubra and Demecarium

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

Moderate

Acetylcholinesterase (Ache) Inhibitors

Why this applies to Demecarium

Demecarium falls under Acetylcholinesterase (Ache) Inhibitors — the group Arenaria Rubra interacts with.

Arenaria rubra, by inhibiting acetylcholinesterase, may theoretically interact with other acetylcholinesterase inhibitors like donepezil and rivastigmine, commonly used in Alzheimer's disease treatment. This interaction could potentially lead to additive effects on acetylcholine levels in the brain. While this might initially seem beneficial in increasing the stimulation of nicotinic and muscarinic receptors, it also raises the risk of additive cholinergic side effects. These side effects could include symptoms such as nausea, vomiting, diarrhea, excessive salivation, sweating, bradycardia, and potentially more severe effects like bronchoconstriction or seizures. Caution should be exercised when combining acetylcholinesterase drugs and Arenaria rubra.
Severity Moderate Likelihood Possible Evidence C

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

Demecarium (Humorsol) is an older eye drop that lowers eye pressure in glaucoma by blocking acetylcholinesterase, the enzyme that breaks down acetylcholine. Lab studies suggest Arenaria rubra may block that same enzyme. So in theory, taking them together could stack up their effects and push acetylcholine levels higher than either alone.

If that happened, you could see more cholinergic side effects: nausea, diarrhea, watery eyes, drooling, sweating, a slow heartbeat, or in rare cases trouble breathing. I want to be clear, though, that this is theoretical and based on weak lab evidence, not real-world reports. Still, since demecarium is a potent drug, it's worth running this by your pharmacist or doctor before combining the two.

Contact Dr. Brian directly if you have additional questions on this interaction

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

Arenaria Rubra Also Interacts With Other Medications

Arenaria Rubra has 16 moderate known drug interactions in our database — the Demecarium one above is one of them. If you take anything else, check it against the full list below.

Moderate 16 No known interaction 2,814 (incl. Demecarium)
Taking anything else?

Check Another of Your Medications Against Arenaria Rubra

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

Everything else you take

See Every Supplement That Interacts With Demecarium

This page covers Arenaria Rubra only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Demecarium page lists 39 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Bacopa (moderate), Bael (moderate), Betel Nut (moderate) and Boxwood (moderate).

By severity: 1 major · 28 moderate · 10 minor.

From our pharmacist’s overview on the Demecarium page

“Most people using demecarium (Humorsol) eye drops for glaucoma are older adults, often the same people reaching for memory supplements like huperzine A and bacopa, and those are what this list flags. Demecarium boosts acetylcholine, and 21 of the 39 supplements on file can add more of the same, raising the risk of cholinergic side effe…”

Reviewed by 2 · Jul 18, 2026

Open the Demecarium interaction page

How much people look this up

Where Arenaria Rubra and Demecarium 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 Arenaria Rubra
Top half

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

29 days ago today
Medication Demecarium
Top half

#977 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 Arenaria Rubra

What is Arenaria Rubra?

Arenaria Rubra
  • Urinary and bladder complaints
  • Kidney stones ("stone-breaking")
  • Mild diuretic
  • Traditional digestive support
  • Antioxidant interest

Arenaria rubra (Spergularia rubra) is a small herb used in folk medicine, mainly for urinary and kidney complaints. Modern evidence is very limited and comes mostly from laboratory studies, so its benefits in people are not proven. Talk with a pharmacist or doctor before using it, especially if you have a medical condition or are pregnant.

Read the full Arenaria Rubra monograph & all interactions
Keep checking

Other Drugs & Arenaria Rubra

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

0Major
16Moderate
0Minor
2,813No known interaction
16 Moderate 2,813 No interaction
Moderate

16 interactions

No interaction 2,813 drugs checked — show the list

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

Showing the 60 most looked-up of 2,813 medications checked with no known interaction — see the full Arenaria Rubra list.

See the full Arenaria Rubra interactions page
See every supplement checked against Demecarium, 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
Arenaria Rubra monograph › Uses, safety, and every drug interaction in one place Demecarium supplement interactions › Every supplement checked against Demecarium, 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 Arenaria Rubra and Demecarium Together: Common Questions

Can you take Arenaria Rubra with Demecarium?
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 Arenaria Rubra and Demecarium 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 Demecarium and Arenaria Rubra?

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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.