Drug & supplement interaction

Mountain Ash + Polythiazide, Prazosin

Polythiazide, Prazosin brand name: Minizide.

Moderate Interaction
The bottom line Moderate

Mountain Ash has a moderate interaction with Polythiazide, Prazosin. Taking large amounts of fresh mountain ash berries may cause kidney damage due to its parasorbic acid constituent.

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

Mountain Ash and Polythiazide, Prazosin

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

Moderate

NEPHROTOXIC DRUGS

Why this applies to Polythiazide, Prazosin

Polythiazide, Prazosin falls under NEPHROTOXIC DRUGS — the group Mountain Ash interacts with.

Taking large amounts of fresh mountain ash berries may cause kidney damage due to its parasorbic acid constituent. Theoretically, taking mountain ash berries with nephrotoxic drugs might increase the risk for kidney damage. Until more is known, advise patients to avoid taking mountain ash berries if they are taking other potentially nephrotoxic drugs.
Some potentially nephrotoxic drugs include cyclosporine (Neoral, Sandimmune); aminoglycosides including amikacin (Amikin), gentamicin (Garamycin, Gentak, others), and tobramycin (Nebcin, others); nonsteroidal anti-inflammatory drugs (NSAIDs) including ibuprofen (Advil, Motrin, Nuprin, others), indomethacin (Indocin), naproxen (Aleve, Anaprox, Naprelan, Naprosyn), piroxicam (Feldene); and numerous others.
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 thing about your combination pill of polythiazide and prazosin (Minizide): the polythiazide part is a thiazide diuretic, a 'water pill' that works in the kidneys. The concern with mountain ash berries isn't about how this medicine is broken down. It's that eating large amounts of fresh berries may stress the kidneys because of a compound called parasorbic acid. Pairing that with a kidney-acting drug could, in theory, add a little extra strain.

I'll be honest with you: this is a theoretical worry based on the plant's chemistry, not on real patient studies. Cooked berries in jam or tea are a different story than concentrated raw berries. Still, to be safe, skip large amounts of fresh mountain ash and check with your pharmacist or doctor before trying it.

References
  1. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.

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

Mountain Ash Also Interacts With Other Medications

Mountain Ash has 354 moderate known drug interactions in our database — the Polythiazide, Prazosin one above is one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Mountain Ash

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

Everything else you take

See Every Supplement That Interacts With Polythiazide, Prazosin

This page covers Mountain Ash only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Polythiazide, Prazosin page lists 228 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), Asarabacca (major) and Dolomite (major).

By severity: 10 major · 193 moderate · 25 minor.

From our pharmacist’s overview on the Polythiazide, Prazosin page

“Minizide pairs polythiazide, a water pill, with prazosin to lower blood pressure, and this list calls for real vigilance rather than a quick skim. Of the 228 supplement and herbal ingredients on file, 10 carry a major rating, and those deserve your attention first.”

Reviewed by 2 · Jul 18, 2026

Open the Polythiazide, Prazosin interaction page

One more smart check

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

We hold 1 real supplement products containing Mountain Ash, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Mountain Ash. Your product may carry other ingredients that interact with Polythiazide, Prazosin too, on top of Mountain Ash — 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 Mountain Ash and Polythiazide, Prazosin 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 Mountain Ash
Steady interest

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

29 days ago today
Medication Polythiazide, Prazosin
Steady interest

#2,597 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 Mountain Ash

What is Mountain Ash?

Mountain Ash
  • Sore throat and hoarseness
  • Digestive upset and constipation
  • Cough and chest congestion
  • Mild urinary complaints
  • Source of vitamin C in folk medicine

Mountain ash (rowan) is a northern-hemisphere tree whose bright red berries are traditionally cooked into jams, syrups, and teas. There is very little reliable human research to support any medical use, and raw berries contain compounds that can cause stomach upset, so cooking is important. If you want to try it, talk with your pharmacist or doctor first.

Read the full Mountain Ash monograph & all interactions
Keep checking

Other Drugs & Mountain Ash

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

0Major
354Moderate
0Minor
2,475No known interaction
Moderate

354 interactions

Showing 60 of 354 moderate interactions — see all 354 on the Mountain Ash page.

No interaction 2,475 drugs checked — show the list
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

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Pharmacist Counseling Corner

Taking Mountain Ash and Polythiazide, Prazosin Together: Common Questions

Can you take Mountain Ash with Polythiazide, Prazosin?
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 Mountain Ash and Polythiazide, Prazosin 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

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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.