Drug & supplement interaction

Octopamine + Doxazosin Mesylate

Doxazosin Mesylate brand name: Cardura.

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

Octopamine has a moderate interaction with Doxazosin Mesylate. In humans, octopamine 450-600 mg daily increases blood pressure in hypotensive patients.

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

Octopamine and Doxazosin Mesylate

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

Moderate

ANTIHYPERTENSIVE DRUGS

Why this applies to Doxazosin Mesylate

Doxazosin Mesylate falls under ANTIHYPERTENSIVE DRUGS — the group Octopamine interacts with.

In humans, octopamine 450-600 mg daily increases blood pressure in hypotensive patients. However, evidence from animal research suggests that octopamine can lower blood pressure. Theoretically, concomitant use of octopamine and antihypertensive drugs might potentiate and/or reduce the activity of antihypertensive drugs.
Some antihypertensive drugs include captopril (Capoten), enalapril (Vasotec), losartan (Cozaar), valsartan (Diovan), diltiazem (Cardizem), Amlodipine (Norvasc), hydrochlorothiazide (HydroDiuril), furosemide (Lasix), and many others.
Severity Moderate Likelihood Possible Evidence B

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 to keep in mind: doxazosin (Cardura) is an alpha-blocker, so it works by relaxing your blood vessels and the muscles around your prostate and bladder. Octopamine acts like a mild stimulant that nudges those same adrenaline-type receptors. So the two are sort of pulling in opposite directions, and the result is a bit unpredictable.

In one direction, octopamine could blunt how well your doxazosin lowers blood pressure. In the other, the combo could lead to a bigger drop in pressure, which matters because doxazosin already tends to cause dizziness or lightheadedness, especially when you stand up. The human evidence here is limited and partly theoretical, so I wouldn't panic, but please check with your pharmacist or doctor before adding octopamine.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Visentin V, Morin N, Fontana E, et al. Dual action of octopamine on glucose transport into adipocytes: inhibition via beta3-adrenoceptor activation and stimulation via oxidation by amine oxidases. J Pharmacol Exp Ther 2001;299:96-104.
  2. Beaumont RE, Cordery P, James LJ, Watson P. Supplementation with a low-dose of octopamine does not influence endurance cycling performance in recreationally active men. J Sci Med Sport. 2017;20(10):952-956. 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

Octopamine Also Interacts With Other Medications

Octopamine has 180 moderate, 171 minor known drug interactions in our database — the Doxazosin Mesylate one above is one of them. If you take anything else, check it against the full list below.

Moderate 180 Minor 171 No known interaction 2,479 (incl. Doxazosin Mesylate)
Taking anything else?

Check Another of Your Medications Against Octopamine

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

From our Q&A

Questions About Octopamine or Doxazosin Mesylate

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Octopamine or Doxazosin Mesylate, 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 Doxazosin Mesylate

This page covers Octopamine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Doxazosin Mesylate page lists 137 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), Tyramine (major) and Adrafinil (moderate).

By severity: 4 major · 112 moderate · 21 minor.

From our pharmacist’s overview on the Doxazosin Mesylate page

“Doxazosin (Cardura) relaxes blood vessels to lower blood pressure and ease enlarged-prostate symptoms, and it already has a reputation for dizziness and first-dose fainting. That is why its list of 137 interacting supplements deserves genuine respect.”

Reviewed by 2 · Jul 18, 2026

Open the Doxazosin Mesylate interaction page

One more smart check

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

We hold 118 real supplement products containing Octopamine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Octopamine. Your product may carry other ingredients that interact with Doxazosin Mesylate too, on top of Octopamine — 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 Octopamine and Doxazosin Mesylate 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 Octopamine
Steady interest

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

29 days ago today
Medication Doxazosin Mesylate
Top half

#1,050 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 Octopamine

What is Octopamine?

  • Weight loss and fat burning
  • Boosting energy
  • Athletic performance
  • Appetite suppression

Octopamine is a stimulant-like compound found in small amounts in some plants (such as bitter orange) and made naturally in the body. It is marketed mostly in weight-loss and sports supplements, but human evidence that it actually helps with fat loss or performance is very limited. Because it can affect the heart and blood pressure and is banned in some sports, talk to a pharmacist or doctor before using it.

Read the full Octopamine monograph & all interactions
Medication

About Doxazosin

What Is Doxazosin Used For?

Brand name: Cardura

Doxazosin tablets (Cardura, Doxazosin, Doxazosin mesylate) are approved to treat the signs and symptoms of benign prostatic hyperplasia (BPH) — an enlarged prostate that causes urinary problems — and to treat high blood pressure (hypertension). Lowering blood pressure reduces the risk of stroke and heart attack. Doxazosin tablets may be used alone or combined with other blood pressure medicines.

Cardura XL (the extended-release tablet) is approved only for BPH symptoms. Cardura XL is not approved for high blood pressure.

See full Doxazosin drug information
Keep checking

Other Drugs & Octopamine

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

0Major
180Moderate
171Minor
2,478No known interaction
180 Moderate 171 Minor 2,478 No interaction
Moderate

180 interactions

Showing 60 of 180 moderate interactions — see all 180 on the Octopamine page.

Minor

171 interactions

Showing 60 of 171 minor interactions — see all 171 on the Octopamine page.

No interaction 2,478 drugs checked — show the list

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

Showing the 60 most looked-up of 2,478 medications checked with no known interaction — see the full Octopamine list.

See the full Octopamine interactions page
See every supplement checked against Doxazosin Mesylate, 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
Octopamine monograph › Uses, safety, and every drug interaction in one place Doxazosin Mesylate supplement interactions › Every supplement checked against Doxazosin Mesylate, ranked by severity Doxazosin 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 Octopamine and Doxazosin Mesylate Together: Common Questions

Can you take Octopamine with Doxazosin Mesylate?
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 Octopamine and Doxazosin Mesylate 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 Doxazosin Mesylate and Octopamine?

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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.