Drug & supplement interaction

Thiamine + Hydrochlorothiazide, Lisinopril

Hydrochlorothiazide, Lisinopril brand names: Zestoretic, Prinzide.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Thiamine and Hydrochlorothiazide, Lisinopril 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 two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Thiamine and Hydrochlorothiazide, Lisinopril

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 Hydrochlorothiazide, Lisinopril and Thiamine 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.

Thiamine safety at a glance

Thiamine overall Generally safe Thiamine is generally very safe when taken by mouth in normal amounts.
Pregnancy Likely Safe When used orally in dietary amounts of 1.4 mg daily. A tolerable upper intake level (UL) has not been established for healthy individuals. Read the full pregnancy detail
Breastfeeding Likely Safe When used orally in dietary amounts of 1.4 mg daily. A tolerable upper intake level (UL) has not been established for healthy individuals. Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Hydrochlorothiazide, Lisinopril and Thiamine? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Hydrochlorothiazide, Lisinopril

Interactions in our licensed database are recorded against drug classes, not just single drug names. Hydrochlorothiazide, Lisinopril is filed under 10 classifications — including lisinopril, ace inhibitors (aceis), thiazide diuretics. Thiamine has documented interactions with 1 drug class — the most serious being trimethoprim (proloprim) (minor) — and none of Hydrochlorothiazide, Lisinopril’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

Thiamine Does Interact With Other Medications

Thiamine has 3 minor known drug interactions in our database — Hydrochlorothiazide, Lisinopril isn’t one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Thiamine

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

What to actually watch for

No Interaction Found — But Data Suggests Thiamine and Hydrochlorothiazide, Lisinopril May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do. 5 of them are worth acting on rather than waiting out — marked below.

  • Shortness of breath / A severe allergic reaction / Hives / Bleeding or bruising / An allergic reaction Worth acting on reported in 4.3% of FDA reports for Hydrochlorothiazide, Lisinopril Additional detail

    Thiamine

    “Orally, thiamine might rarely cause dermatitis and other allergic reactions. Parenterally, thiamine can cause anaphylactoid and hypersensitivity reactions, but this is also rare (”

    Thiamine · Natural Medicines adverse-effect record, reported in acute respiratory distress syndrome (ards).

    4 sources cited
    1. 15. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
    2. 35585. Rogovik, A. L., Vohra, S., and Goldman, R. D. Safety considerations and potential interactions of vitamins: should vitamins be considered drugs? Ann.Pharmacother. 2010;44(2):311-324. PubMed
    3. 105445. Thiamine hydrochloride injection package insert. Lake Zurich, IL: Fresenius Kabi, LLC; September 2019.
    4. 91170. Arruti N, Bernedo N, Audicana MT, Villarreal O, Uriel O, Muñoz D. Systemic allergic dermatitis caused by thiamine after iontophoresis. Contact Dermatitis. 2013 Dec;69(6):375-6. PubMed

    Hydrochlorothiazide, Lisinopril

    Listed in the ADVERSE REACTIONS section of the FDA label for Hydrochlorothiazide, Lisinopril, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

  • Numbness or tingling / Low blood pressure / Itching / Swelling / A skin rash Additional detail

    Thiamine

    Recorded for Thiamine in the same Natural Medicines adverse-effect record shown under Shortness of breath / A severe allergic reaction / Hives / Bleeding or bruising / An allergic reaction above.

    Hydrochlorothiazide, Lisinopril

    Listed in the ADVERSE REACTIONS section of the FDA label for Hydrochlorothiazide, Lisinopril. Read the label on DailyMed ›

Reported for Thiamine but not commonly for Hydrochlorothiazide, Lisinopril: bleeding in the gut.

Effects for Hydrochlorothiazide, Lisinopril come from the ADVERSE REACTIONS section of its FDA label; effects for Thiamine come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 10,177 voluntary FDA FAERS reports for Hydrochlorothiazide, Lisinopril that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Thiamine in Pregnancy & Breastfeeding

Pregnancy And Lactation Likely Safe

When used orally in dietary amounts of 1.4 mg daily. A tolerable upper intake level (UL) has not been established for healthy individuals.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

Worth knowing

No Interaction — But Hydrochlorothiazide, Lisinopril May Lower Your Thiamine Levels

These two do not interact. The relationship runs the other way: the licensed record lists Hydrochlorothiazide, Lisinopril as associated with lower Thiamine levels — rated “Moderate Depletion”.

High doses of diuretics can increase thiamine excretion and increase the risk of deficiency. Increased urinary thiamine excretion and thiamine deficiency may occur in some people treated with diuretics, especially in high doses (e.g., more than 80 mg furosemide daily) for several months. Although most case reports involve furosemide, animal data suggest that the effect may occur with any diuretic. Diuretic-induced thiamine deficiency appears to be most common in elderly people with inadequate dietary intake and to be rare in people less than 60 years of age. Thiamine deficiency in people taking diuretics is a concern because it might worsen heart failure. Limited research suggests that supplementation with thiamine 200 mg daily may improve left ventricular ejection fraction and functional capacity in some thiamine-deficient people treated with high doses of furosemide for heart failure. However, other studies have found no improvement. It's too soon to recommend routine thiamine supplementation for people on prolonged, high-dose diuretic therapy. Monitor for thiamine deficiency.

THIAMINE — Moderate Depletion

See every medication linked to lower Thiamine levels · See the full Hydrochlorothiazide, Lisinopril nutrient report

Disclaimer: This checker finds which nutrients might be depleted by prescription or over-the-counter medications. Each nutrient depletion issue is rated based on clinical significance. Use your own professional judgment prior to making clinical decisions.© 2026 Therapeutic Research Center

Overlapping uses

What Hydrochlorothiazide, Lisinopril Is Prescribed For, and What Thiamine Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Hydrochlorothiazide, Lisinopril is a prescription medicine with approved uses on its FDA label. Thiamine is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Hydrochlorothiazide, Lisinopril is prescribed for: Lisinopril and hydrochlorothiazide tablets — sold as the brand Zestoretic and as the generic combination — are used to treat high blood pressure (hypertension). Lowering blood pressure reduces the risk of serious cardiovascular events such as stroke and heart attack. This is a fixed-dose combination product and is not intended as a first-line (initial) treatment for high blood pressure. It is typically prescribed for patients whose blood pressure is not adequately controlled on a single medication alone.

Thiamine has been studied for:

  • Heart failure studied, not established Thiamine has been studied for this. Natural Medicines rates the evidence: Possibly Ineffective Read what the research shows

    Thiamine for heart failure

    Most research suggests that oral or intravenous thiamine does not improve outcomes in patients with heart failure.

  • Kidney failure studied, not established Thiamine has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Thiamine for kidney failure

    Oral thiamine has only been evaluated in combination with other ingredients; its effect when used alone is unclear.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Hydrochlorothiazide, Lisinopril on your own; if you are taking Thiamine for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

Everything else you take

See Every Supplement That Interacts With Hydrochlorothiazide, Lisinopril

This page covers Thiamine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Hydrochlorothiazide, Lisinopril page lists 236 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 · 199 moderate · 27 minor.

From our pharmacist’s overview on the Hydrochlorothiazide, Lisinopril page

“I would not add a supplement casually alongside hydrochlorothiazide and lisinopril (Zestoretic, Prinzide). This combination lowers blood pressure with a water pill plus an ACE inhibitor, and most interacting ingredients either drag pressure down too far or push back against the drug, while smaller groups strain the kidneys, drain potas…”

Reviewed by 2 · Jul 18, 2026

Open the Hydrochlorothiazide, Lisinopril interaction page

One more smart check

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

We hold 3 real supplement products containing Thiamine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Thiamine. Even though Thiamine itself has no known interaction with Hydrochlorothiazide, Lisinopril, 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 Thiamine and Hydrochlorothiazide, Lisinopril 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 Thiamine
Top 25%

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

29 days ago today
Medication Hydrochlorothiazide, Lisinopril
Top 25%

#565 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 Thiamine reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Thiamine and Hydrochlorothiazide, Lisinopril 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 Thiamine

What is Thiamine?

  • Preventing or treating thiamine deficiency
  • Beriberi
  • Wernicke-Korsakoff syndrome (alcohol-related)
  • Supporting energy and nerve function
  • General B-vitamin supplementation

Thiamine (vitamin B1) is an essential nutrient your body needs to turn food into energy and to keep your nerves and heart healthy. Most people get enough from food, but supplements are clearly useful for deficiency, certain medical conditions, and people with heavy alcohol use. Talk with your pharmacist or doctor before starting it, especially if you have a chronic illness.

Tablets, capsules, oral liquids, injectable solutions (prescription), part of B-complex and multivitamins

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

Thiamine: dosing

The right dose of thiamine depends on your age, health, and the reason you are taking it. There is a recommended daily intake for general nutrition, and higher amounts are sometimes used by doctors to treat a deficiency.For supplements, the best approach is to follow the directions on the product label and not exceed them without guidance.

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

Read the full Thiamine monograph & all interactions
Medication

About Lisinopril and Hydrochlorothiazide

What Is Lisinopril and Hydrochlorothiazide Used For?

Brand names: Zestoretic, Prinzide

Lisinopril and hydrochlorothiazide tablets — sold as the brand Zestoretic and as the generic combination — are used to treat high blood pressure (hypertension). Lowering blood pressure reduces the risk of serious cardiovascular events such as stroke and heart attack.

This is a fixed-dose combination product and is not intended as a first-line (initial) treatment for high blood pressure. It is typically prescribed for patients whose blood pressure is not adequately controlled on a single medication alone.

See full Lisinopril and Hydrochlorothiazide drug information
Keep checking

Other Drugs & Thiamine

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

0Major
0Moderate
3Minor
2,826No known interaction
Minor

3 interactions

No interaction 2,826 drugs checked — show the list
Evidence & sources

Thiamine References

The 7 references that drive our Thiamine 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. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
  2. Yates AA, Schlicker SA, Suitor CW. Dietary reference intakes: The new basis for recommendations for calcium and related nutrients, B vitamins, and choline. J Am Diet Assoc 1998;98:699-706. PubMed
  3. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline (2000). Washington, DC: National Academy Press, 2000. Available at: http://b
  4. Rogovik, A. L., Vohra, S., and Goldman, R. D. Safety considerations and potential interactions of vitamins: should vitamins be considered drugs? Ann.Pharmacother. 2010;44(2):311-324. PubMed
  5. Arruti N, Bernedo N, Audicana MT, Villarreal O, Uriel O, Muñoz D. Systemic allergic dermatitis caused by thiamine after iontophoresis. Contact Dermatitis. 2013 Dec;69(6):375-6. PubMed
  6. Thiamine hydrochloride injection package insert. Lake Zurich, IL: Fresenius Kabi, LLC; September 2019.
  7. Vora B, Wen A, Yee SW, et al. The Effect of Trimethoprim on Thiamine Absorption: A Transporter-Mediated Drug-Nutrient Interaction. Clin Pharmacol Ther 2023;114(2):381-392.

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 Thiamine and Hydrochlorothiazide, Lisinopril Together: Common Questions

Is it safe to take Thiamine with Hydrochlorothiazide, Lisinopril?
We do not list a known interaction between Thiamine and Hydrochlorothiazide, Lisinopril. 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.
Do Thiamine and Hydrochlorothiazide, Lisinopril have any of the same side effects?
Yes — our sources link each of them separately to 10 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
Can Hydrochlorothiazide, Lisinopril lower my Thiamine levels?
Natural Medicines records Hydrochlorothiazide, Lisinopril as a medicine that can deplete Thiamine. That is the opposite direction to an interaction — it is a reason some people are told to take a supplement, not a reason to avoid one. Do not start one on the strength of this page; ask your pharmacist or doctor whether it applies to you.
Are Thiamine and Hydrochlorothiazide, Lisinopril used for the same thing?
They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Thiamine in each. That is a conversation for your prescriber, especially if Hydrochlorothiazide, Lisinopril is being adjusted to a target.
How was the Thiamine and Hydrochlorothiazide, Lisinopril combination checked?
Interactions in our licensed database are recorded against drug classes. Hydrochlorothiazide, Lisinopril is filed under 10 classifications, and Thiamine has documented interactions with 1 drug class — none of Hydrochlorothiazide, Lisinopril'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 Thiamine interact with any other medications?
Yes. Thiamine has 3 documented drug interactions in our database — Hydrochlorothiazide, Lisinopril 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 Hydrochlorothiazide, Lisinopril interact with any supplements?
Yes. Hydrochlorothiazide, Lisinopril has documented interactions with 236 supplements in our database — Thiamine is not one of them. The Hydrochlorothiazide, Lisinopril interaction page linked on this page lists every one, ranked by severity.

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

Still Have a Question About Hydrochlorothiazide, Lisinopril and Thiamine?

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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.