Drug & supplement interaction

Melatonin + Triamterene

Triamterene brand name: Dyrenium.

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

Melatonin has a moderate interaction with Triamterene. Theoretically, taking melatonin with antihypertensive drugs might increase the risk of hypotension or hypertension.

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

Melatonin and Triamterene

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

Moderate

ANTIHYPERTENSIVE DRUGS

Why this applies to Triamterene

Triamterene falls under ANTIHYPERTENSIVE DRUGS — the group Melatonin interacts with.

Theoretically, taking melatonin with antihypertensive drugs might increase the risk of hypotension or hypertension.
Some clinical research suggests that taking melatonin decreases blood pressure in healthy adults. Also, melatonin seems to lower systolic and diastolic blood pressure in individuals with high blood pressure at nighttime or untreated essential hypertension. However, melatonin seems to worsen blood pressure in patients who are taking antihypertensive medications. Immediate-release melatonin 5 mg at night in combination with nifedipine GITS (Procardia XL) increases systolic blood pressure an average of 6.5 mmHg, diastolic blood pressure by an average of 4.9 mmHg, and heart rate by 3.9 bpm. Also, results from animal research suggest that melatonin reduces the effectiveness of certain antihypertensive drugs, including methoxamine and clonidine.
Severity Moderate Likelihood Possible Evidence A

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

You're taking triamterene, a water pill that helps your body get rid of extra fluid while holding onto potassium. Even though it's mainly used for swelling, it can also nudge your blood pressure down a bit. Melatonin isn't a prodrug situation here, so this isn't about one activating the other. The concern is simpler: melatonin can affect blood pressure, and the research is a little mixed about which direction it goes when you're already on a blood pressure or fluid medication.

Some studies suggest melatonin may actually blunt the blood-pressure-lowering effect of these medicines, so your numbers could run a touch higher than expected. This is rated moderate and only possible, not guaranteed. Occasional use for jet lag is usually low-risk, but please check with your pharmacist or doctor before making melatonin a nightly habit, and keep an eye on your blood pressure.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Arangino S, Cagnacci A, Angiolucci M, et al. Effects of melatonin on vascular reactivity, catecholamine levels, and blood pressure in healthy men. Am J Cardiol 1999;83:1417-9. PubMed
  2. Lusardi P, et al. Cardiovascular effects of melatonin in hypertensive patients well controlled by nifedipine: a 24-hour study. Br J Clin Pharmacol 2000;49:423-7. PubMed
  3. Cagnacci, A., Arangino, S., Angiolucci, M., Melis, G. B., Facchinetti, F., Malmusi, S., and Volpe, A. Effect of exogenous melatonin on vascular reactivity and nitric oxide in postmenopausal women: role of hormone replacement therapy. Clin Endocrinol (Oxf PubMed
  4. Kitajima, T., Kanbayashi, T., Saitoh, Y., Ogawa, Y., Sugiyama, T., Kaneko, Y., Sasaki, Y., Aizawa, R., and Shimisu, T. The effects of oral melatonin on the autonomic function in healthy subjects. Psychiatry Clin Neurosci. 2001;55(3):299-300. PubMed
  5. Scheer, F. A., Van Montfrans, G. A., van Someren, E. J., Mairuhu, G., and Buijs, R. M. Daily nighttime melatonin reduces blood pressure in male patients with essential hypertension. Hypertension 2004;43(2):192-197. PubMed
  6. Cagnacci, A., Cannoletta, M., Renzi, A., Baldassari, F., Arangino, S., and Volpe, A. Prolonged melatonin administration decreases nocturnal blood pressure in women. Am J Hypertens. 2005;18(12 Pt 1):1614-1618. PubMed
  7. Weekley, L. B. Melatonin-induced relaxation of rat aorta: interaction with adrenergic agonists. J Pineal Res 1991;11(1):28-34. PubMed
  8. Grossman, E., Laudon, M., Yalcin, R., Zengil, H., Peleg, E., Sharabi, Y., Kamari, Y., Shen-Orr, Z., and Zisapel, N. Melatonin reduces night blood pressure in patients with nocturnal hypertension. Am J Med 2006;119(10):898-902. PubMed
  9. Grossman, E., Laudon, M., and Zisapel, N. Effect of melatonin on nocturnal blood pressure: meta-analysis of randomized controlled trials. Vasc.Health Risk Manag. 2011;7:577-584. PubMed
  10. Cagnacci, A., Arangino, S., Angiolucci, M., Maschio, E., and Melis, G. B. Influences of melatonin administration on the circulation of women. Am J Physiol 1998;274(2 Pt 2):R335-R338. 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

Melatonin Also Interacts With Other Medications

Melatonin has 1,116 moderate, 346 minor known drug interactions in our database — the Triamterene one above is one of them. If you take anything else, check it against the full list below.

Moderate 1,116 Minor 346 No known interaction 1,368 (incl. Triamterene)
Taking anything else?

Check Another of Your Medications Against Melatonin

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

From our Q&A

Questions About Melatonin or Triamterene

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

This page covers Melatonin only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Triamterene page lists 165 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 Siberian Cocklebur (major).

By severity: 6 major · 136 moderate · 23 minor.

From our pharmacist’s overview on the Triamterene page

“Because triamterene (Dyrenium) both lowers blood pressure and hangs onto potassium, its supplement list calls for real vigilance. Six of the 165 ingredients on file carry a major rating, and those six deserve your attention before any others.”

Reviewed by 2 · Jul 18, 2026

Open the Triamterene interaction page

One more smart check

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

We hold 2,885 real supplement products containing Melatonin, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Melatonin. Your product may carry other ingredients that interact with Triamterene too, on top of Melatonin — 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 Melatonin and Triamterene 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 Melatonin
Top 5%

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

29 days ago today
Medication Triamterene
Steady interest

#2,419 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 Melatonin

What is Melatonin?

Melatonin
  • Trouble falling asleep (insomnia)
  • Jet lag
  • Delayed sleep phase syndrome
  • Non-24-hour sleep-wake disorder
  • Shift-work sleep problems
  • Sleep problems in some children with conditions like autism or ADHD

Melatonin is a hormone your body makes naturally to help control your sleep-wake cycle, and the supplement form is widely used to help with sleep timing problems and jet lag. The evidence is strongest for certain circadian (body-clock) disorders and is more mixed for everyday insomnia. It is generally well tolerated for short-term use, but talk with your pharmacist or doctor before starting, especially for children or during pregnancy.

Read the full Melatonin monograph & all interactions
Medication

About Triamterene

What Is Triamterene Used For?

Brand name: Dyrenium

Triamterene treats edema (fluid buildup and swelling) linked to several conditions. These include heart failure, cirrhosis of the liver, and nephrotic syndrome (a kidney condition). It also treats steroid-induced edema, idiopathic edema (swelling with no clear cause), and edema from secondary hyperaldosteronism (high levels of the hormone aldosterone caused by another condition).

It can be used alone or with other diuretics, for extra water-removing effect or to help the body hold on to potassium. It can also help when other diuretics, such as thiazides, have not worked well enough because of secondary hyperaldosteronism. Dyrenium and triamterene capsules carry the same uses.

See full Triamterene drug information
Keep checking

Other Drugs & Melatonin

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

0Major
1,116Moderate
346Minor
1,367No known interaction
1,116 Moderate 346 Minor 1,367 No interaction
Moderate

1,116 interactions

Showing 60 of 1,116 moderate interactions — see all 1,116 on the Melatonin page.

Minor

346 interactions

Showing 60 of 346 minor interactions — see all 346 on the Melatonin page.

No interaction 1,367 drugs checked — show the list

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

Showing the 60 most looked-up of 1,367 medications checked with no known interaction — see the full Melatonin list.

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

Can you take Melatonin with Triamterene?
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 Melatonin and Triamterene 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.