Supplements and Bendroflumethiazide.
Bendroflumethiazide is a thiazide diuretic: it inhibits sodium reabsorption in the distal tubule, a milder diuresis than loop agents.
Bendroflumethiazide is a thiazide diuretic, or the thiazide-like agents that share the same prescribing space. The class inhibits sodium reabsorption in the distal convoluted tubule. It produces a milder diuresis than loop agents, but with a longer plasma half life suitable for dosing once a day in hypertension. The metabolic profile carries hypokalaemia, hyponatraemia (especially in older patients on combined antihypertensives), hyperuricaemia, and a small impact on glucose control. Supplement-relevant points sit on the electrolyte side. Potassium and magnesium supplementation is often given alongside in patients with low baseline electrolytes. Liquorice opposes thiazide effect through sodium retention mediated by aldosterone. The combination with NSAIDs is the same as for loop diuretics. Blunted antihypertensive effect and added renal stress. Indapamide sits in the same prescribing space as bendroflumethiazide in current UK practice and shares the profile.
Below are the 7 documented pairs we have explicitly assessed against Bendroflumethiazide in the Distil database: 7 amber. The pairs cluster around 4 mechanisms: Additive blood-pressure lowering, Hypercalcaemia risk, Reduced renal lithium clearance, and Renal zinc wasting (drug-induced). Every call is cited to either a clinical reference (PMID) or the British National Formulary. Anything not on this list is either still to be assessed or beyond our database scope. The checker beneath surfaces assessments by supplement, and the missing-item form at the bottom of the page routes any uncatalogued supplement into our next curation pass.
Documented interactions
Additive blood-pressure lowering
Hibiscus tends to lower blood pressure on its own, and bendroflumethiazide is a water tablet used to lower it. Taken together the blood-pressure effects may stack, so watch for dizziness on standing, especially in the first couple of weeks. If symptoms appear, tell your GP.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Taurine tends to lower blood pressure on its own, and bendroflumethiazide is a water tablet used to lower it. Taken together the blood-pressure effects may stack, so watch for dizziness on standing, especially in the first couple of weeks. The added effect tends to be modest. If symptoms appear, tell your GP.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Hypercalcaemia risk
Thiazide diuretics like bendroflumethiazide make the kidneys hold on to more calcium, and a calcium supplement adds more calcium on top. Taken together, the two may push blood calcium too high, especially with higher calcium doses or if a parathyroid problem is present. Many people take both without trouble, but it is worth your prescriber knowing so your blood calcium can be checked from time to time.
Thiazide diuretics like bendroflumethiazide make the kidneys hold on to more calcium, and vitamin D raises how much calcium you absorb from food. Taken together, especially at higher vitamin D doses or alongside calcium supplements, the two may push blood calcium too high. Standard replacement doses of vitamin D with a routine calcium check tend to be fine, but it is worth your prescriber knowing you take both.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Reduced renal lithium clearance
Thiazide water tablets such as bendroflumethiazide make the kidneys hold on to lithium and have the strongest lithium-raising effect of these medicines. With prescription lithium this is a recognised cause of toxicity. At the small amount of lithium in a typical lithium orotate supplement (around 5 mg) the effect is expected to be very small; it matters more for higher-strength products (around 20 mg) and for anyone whose kidney function is reduced. If you take a thiazide diuretic, check with your pharmacist or GP before using a lithium supplement.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Renal zinc wasting (drug-induced)
Bendroflumethiazide and other thiazide water tablets make your kidneys pass more zinc into your urine, which can lower your body's zinc over months of use. Taking a zinc supplement is generally helpful here rather than harmful, since it tops up what the diuretic is draining. If you have been on a thiazide long term and notice things like a poor sense of taste or slow-healing skin, mention it to your GP, who can check your zinc.
Bendroflumethiazide and other thiazide water tablets make your kidneys pass more zinc into your urine, which can lower your body's zinc over months of use. Taking a zinc supplement is generally helpful here rather than harmful, since it tops up what the diuretic is draining. If you have been on a thiazide long term and notice things like a poor sense of taste or slow-healing skin, mention it to your GP, who can check your zinc.
What this list does not say. Pairs not flagged here are not implicitly safe. They are either not yet in our database, or fall outside our inclusion scope (food-supplement interactions only; for drug-drug interactions, the BNF is authoritative). Use the checker below to surface any supplement, and submit a missing item if you take something we have not catalogued.
How we grade severity, choose what's in scope, and what we exclude.
Every call on this page is reasoned. We publish the full rubric for severity tiers, the medication inclusion logic, the evidence grades we accept, and what we deliberately leave out. About three thousand words. Worth reading once if you use this tool more than occasionally.
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- the same graded, cited interaction check across your whole stack, not just the pairs you thought to type in
- where your current routine may be leaving you short of your goals
- the evidence-backed compounds worth adding, and the ones worth dropping
It's a paid report: £79, or £49 for the first 25 customers. The interactions check is one section of it, and you can read a real one in full before you buy.
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