Furosemide and Vitamin B1: what the published research says
PubMed indexes 8 records that name Furosemide and Vitamin B1 together, either in the title or in an interaction, co-administration, or pharmacokinetic context. Each one is listed below with its study design and, where the abstract states one, the authors’ own conclusion, quoted and linked. This page reports that literature. It does not tell you whether to combine them.
Every statement below is attributed to a named, dated, linked source.
This page lists published research relevant to Furosemide and Vitamin B1. It deliberately does not state whether the combination is safe, whether it interacts, in which direction, at what dose, or how far apart to take them.
A study appearing here is not proof that an interaction exists. Two substances can be named together in a paper that never tested them in combination, and a source listed as background may cover only one of them.
Findings are quoted from each abstract as the authors wrote them. NutriStack has not re-analysed, pooled, or reconciled them, and they may disagree with each other.
NutriStack’s own interaction assessment for this pair is not published here. It has not completed qualified-human clinical review, so it is withheld from search. See the publication gate.
Nothing here is medical advice. Decisions about prescription medication and supplements belong with your prescriber or pharmacist, who can see your full regimen.
The research
8 studies naming Furosemide and Vitamin B1.
Strongest relevance first: papers naming both substances in the title, then human trials and systematic reviews.
“Thiamine substantially decreases in most hypervolemic patients receiving intravenous furosemide treatment during the hospital stay. Thiamine levels were significantly decreased with furosemide treatment in especially HF patients, but the decrease in thiamine levels did not detected at the same rate in RF patients. Diuretic-induced thiamine loss may be less likely in RF patients, probably due to a reduction in excretion.”
Names both Furosemide and Vitamin B1 in its title.
The American journal of medicine · 1995 · PMID 7733128
Clinical TrialRandomized Controlled TrialResearch Support, U.S. Gov't, Non-P.H.S.
“Thiamine repletion can improve left ventricular function and biochemical evidence of thiamine deficiency in some patients with moderate-to-severe CHF who are receiving longterm furosemide therapy.”
Names both Furosemide and Vitamin B1 in its title.
The American journal of medicine · 1991 · PMID 1867241
Comparative StudyHuman subjects
“These preliminary findings suggest that long-term furosemide therapy may be associated with clinically significant thiamine deficiency due to urinary loss and contribute to impaired cardiac performance in patients with CHF. This deficit may be prevented or corrected by appropriate thiamine supplements.”
Names both Furosemide and Vitamin B1 in its title.
The American journal of medicine · 2016 · PMID 26899752
ReviewHuman subjects
“Limited data suggest that thiamine supplementation is capable of increasing left ventricular ejection fraction and improving functional capacity in patients with heart failure and a reduced left ventricular ejection fraction who were treated with diuretics (predominantly furosemide). Therefore, it may be reasonable to provide such patients with thiamine supplementation during heart failure exacerbations.”
Names both Furosemide and Vitamin B1 in its title.
“The present results indicate that furosemide administration is not the primary cause of thiamine deficiency in rats with adequate thiamine intake. Furosemide aggravates thiamine deficiency only in situations associated with insufficient thiamine intake, causing cardiac structural alterations, such as myocardial fiber hypotrophy, poor microvascularization, and mitochondrial degeneration.”
Names both Furosemide and Vitamin B1 in its title.
The Canadian journal of clinical pharmacology = Journal canadien de pharmacologie clinique · 2003 · PMID 14712323
Human subjects
“These findings suggest that thiamine deficiency occurs in a substantial proportion of congestive heart failure patients being treated with furosemide.”
Names both Furosemide and Vitamin B1 in its title.
Journal of internal medicine · 2000 · PMID 10809999
Human subjects
“The elderly patients with heart failure treated with furosemide have not reduced the storage form of thiamine, TPP, but only TP. This change is most likely not an expression of a thiamine deficiency, but rather of an altered metabolism of thiamine, which is not understood at present.”
Names both Furosemide and Vitamin B1 in its title.
The Journal of laboratory and clinical medicine · 1999 · PMID 10482307
Human subjects
“Urinary flow rate, being the single significant predictor, explained 78% (R2 = 0.78) of the variability in thiamine excretion rates. These findings indicate that urinary thiamine loss is caused by a nonspecific, flow-dependent mechanism common to all of the diuretics tested.”
Names both Furosemide and Vitamin B1 in its title.
Limitations
What this evidence cannot tell you.
Search-based evidence indexes have real limits, and it is worth being explicit about them:
Selection. These records were found by searching PubMed titles and abstracts for both substance names alongside interaction and pharmacokinetic terms. Relevant work that phrases things differently, or is not indexed in PubMed, will be missing.
No effect size. The quoted conclusions are the authors’ words about their own study. We have not extracted effect direction or magnitude, and a single study’s conclusion is not a consensus.
Population mismatch. Findings in healthy volunteers, animals, or a specific patient group may not transfer to you, your dose, or your formulation.
Absence is not safety. Few published studies means the combination is under-studied, which is not the same as established as safe.
Nearby evidence
Other pairs with published research.
Pages covering Furosemide or Vitamin B1 alongside a different substance.
NutriStack is a free iPhone app for organising a supplement routine: what you take, when, and what the published record says about it. Its exploratory interaction checker covers Furosemide, Vitamin B1, and several hundred other substances.
The checker is a research and organisation tool, not a clinical decision aid, and its per-pair assessments are excluded from search until they pass claim-level review.
NutriStack is an informational and organizational tool, not a medical service, and not a substitute for professional advice. Always consult a qualified healthcare professional before starting, stopping, or changing any supplement or medication.
