Potassium and medications.
Potassium is in the Distil supplement database, evidence Grade A. The page below lists every medication we have explicitly assessed it against.
Potassium, usually supplemented as potassium citrate, is one of the strongest dietary levers for blood pressure. The evidence is Grade A: a 33-trial meta-analysis from Whelton in 1997, a WHO-commissioned analysis from Aburto in 2013 showing a 24% reduction in stroke risk, and the DASH trial all support it for blood pressure and cardiovascular health, with the citrate form also helping prevent oxalate kidney stones. Dietary increase from bananas, potatoes and leafy greens is first-line; UK capsules are capped low at 99 to 200mg for regulatory reasons, so supplements are an adjunct at 400 to 1,000mg a day in divided doses. The interactions here are serious and non-negotiable. Potassium is contraindicated in kidney disease because of hyperkalaemia risk, and it must be flagged to a GP with potassium-sparing diuretics such as spironolactone, with ACE inhibitors like ramipril, and with ARBs like losartan, all of which already raise potassium. Take it with food to limit stomach irritation.
Below are the 21 documented pairs we have explicitly assessed for Potassium: 15 red and 6 amber. The pairs cluster around 2 mechanisms: Additive hyperkalaemia (raised potassium) and Digoxin-potassium balance (keep in range). Every call is cited to either a clinical reference (PMID) or the British National Formulary. Anything not listed here is either still to be assessed or beyond our database scope. The checker beneath surfaces assessments by medication, and the missing-item form at the bottom of the page routes any uncatalogued medication into our next curation pass.
Documented interactions
Additive hyperkalaemia (raised potassium)
Amiloride is a potassium-sparing diuretic, which means it makes the body hold on to potassium. Adding a potassium supplement on top can push potassium to a dangerous level and affect the heart rhythm. This is one of the higher-risk combinations. Do not take potassium with amiloride unless your specialist has advised it and is monitoring your blood potassium closely.
Candesartan raises blood potassium by reducing how much the kidneys pass out. A potassium supplement adds more potassium on top. Together they can push potassium high enough to affect the heart rhythm, which can be dangerous. Do not take a potassium supplement alongside candesartan unless your GP has specifically advised it and is checking your blood potassium.
Ciclosporin tends to raise blood potassium because it reduces how much potassium the kidneys pass out. A potassium supplement adds more potassium on top, and together they can push potassium high enough to affect the heart rhythm, which can be dangerous. People on ciclosporin are usually under specialist or transplant follow-up with regular blood tests, so do not start a potassium supplement unless that team has specifically advised it and is checking your blood potassium.
Co-trimoxazole contains trimethoprim, which makes the body hold on to potassium by acting on the kidney in much the same way as the potassium-sparing diuretic amiloride. Adding a potassium supplement on top can push potassium to a dangerous level and affect the heart rhythm, and in older people on certain heart or blood-pressure medicines this combination has been linked to sudden death. Do not take potassium with co-trimoxazole unless your specialist has advised it and is monitoring your blood potassium closely.
Enalapril raises blood potassium by reducing how much the kidneys pass out. A potassium supplement adds more potassium on top. Together they can push potassium high enough to affect the heart rhythm, which can be dangerous. Do not take a potassium supplement alongside enalapril unless your GP has specifically advised it and is checking your blood potassium.
Eplerenone is a potassium-sparing medicine that makes the body hold on to potassium. Adding a potassium supplement on top can push potassium to a dangerous level and affect the heart rhythm. This is one of the higher-risk combinations. Do not take potassium with eplerenone unless your specialist has advised it and is monitoring your blood potassium closely.
Irbesartan raises blood potassium by reducing how much the kidneys pass out. A potassium supplement adds more potassium on top. Together they can push potassium high enough to affect the heart rhythm, which can be dangerous. Do not take a potassium supplement alongside irbesartan unless your GP has specifically advised it and is checking your blood potassium.
Lisinopril raises blood potassium by reducing how much the kidneys pass out. A potassium supplement adds more potassium on top. Together they can push potassium high enough to affect the heart rhythm, which can be dangerous. Do not take a potassium supplement alongside lisinopril unless your GP has specifically advised it and is checking your blood potassium.
Losartan raises blood potassium by reducing how much the kidneys pass out. A potassium supplement adds more potassium on top. Together they can push potassium high enough to affect the heart rhythm, which can be dangerous. Do not take a potassium supplement alongside losartan unless your GP has specifically advised it and is checking your blood potassium.
Perindopril raises blood potassium by reducing how much the kidneys pass out. A potassium supplement adds more potassium on top. Together they can push potassium high enough to affect the heart rhythm, which can be dangerous. Do not take a potassium supplement alongside perindopril unless your GP has specifically advised it and is checking your blood potassium.
Ramipril raises blood potassium by reducing how much the kidneys pass out. A potassium supplement adds more potassium on top. Together they can push potassium high enough to affect the heart rhythm, which can be dangerous. Do not take a potassium supplement alongside ramipril unless your GP has specifically advised it and is checking your blood potassium.
Sacubitril/valsartan (Entresto) contains valsartan, which raises blood potassium by reducing how much the kidneys pass out. A potassium supplement adds more potassium on top. Together they can push potassium high enough to affect the heart rhythm, which can be dangerous. Do not take a potassium supplement alongside sacubitril/valsartan unless your specialist has specifically advised it and is checking your blood potassium.
Spironolactone is a potassium-sparing diuretic, which means it makes the body hold on to potassium. Adding a potassium supplement on top can push potassium to a dangerous level and affect the heart rhythm. This is one of the higher-risk combinations. Do not take potassium with spironolactone unless your specialist has advised it and is monitoring your blood potassium closely.
Tacrolimus tends to raise blood potassium by reducing how much the kidneys pass out. A potassium supplement adds more potassium on top, and together they can push potassium high enough to affect the heart rhythm, which can be dangerous. People on tacrolimus are usually under specialist or transplant follow-up with regular blood tests, so do not add a potassium supplement unless that team has specifically advised it and is checking your blood potassium.
Trimethoprim makes the body hold on to potassium by acting on the kidney in much the same way as the potassium-sparing diuretic amiloride. Adding a potassium supplement on top can push potassium to a dangerous level and affect the heart rhythm. This is one of the higher-risk combinations. Do not take potassium with trimethoprim unless your specialist has advised it and is monitoring your blood potassium closely, especially if you are older or have kidney problems.
Anti-inflammatory painkillers like celecoxib can make the kidneys hold on to a little more potassium. On their own the effect is usually small, but added to a potassium supplement, and especially if your kidneys are not working at full strength or you take a blood-pressure medicine that also raises potassium, it can nudge your potassium higher. If you take celecoxib regularly, mention any potassium supplement to your GP or pharmacist.
Anti-inflammatory painkillers like diclofenac can make the kidneys hold on to a little more potassium. On their own the effect is usually small, but added to a potassium supplement, and especially if your kidneys are not working at full strength or you take a blood-pressure medicine that also raises potassium, it can nudge your potassium higher. If you take diclofenac regularly, mention any potassium supplement to your GP or pharmacist.
Anti-inflammatory painkillers like etoricoxib can make the kidneys hold on to a little more potassium. On their own the effect is usually small, but added to a potassium supplement, and especially if your kidneys are not working at full strength or you take a blood-pressure medicine that also raises potassium, it can nudge your potassium higher. If you take etoricoxib regularly, mention any potassium supplement to your GP or pharmacist.
Anti-inflammatory painkillers like ibuprofen can make the kidneys hold on to a little more potassium. On their own the effect is usually small, but added to a potassium supplement, and especially if your kidneys are not working at full strength or you take a blood-pressure medicine that also raises potassium, it can nudge your potassium higher. If you take ibuprofen regularly, mention any potassium supplement to your GP or pharmacist.
Anti-inflammatory painkillers like naproxen can make the kidneys hold on to a little more potassium. On their own the effect is usually small, but added to a potassium supplement, and especially if your kidneys are not working at full strength or you take a blood-pressure medicine that also raises potassium, it can nudge your potassium higher. If you take naproxen regularly, mention any potassium supplement to your GP or pharmacist.
Digoxin-potassium balance (keep in range)
Potassium and digoxin are closely linked. Keeping your potassium in the normal range is actually important on digoxin: when potassium runs low, digoxin becomes more toxic and can affect the heart rhythm. So a potassium supplement is not something to simply avoid. The catch is balance. Too much potassium can reduce how well digoxin works and, if it climbs too high, add to the risk of a slow or irregular heartbeat. Do not start a potassium supplement on your own while taking digoxin. Let your doctor decide whether you need one and have your potassium checked, especially if your kidneys are not working at full capacity or you take other medicines that raise potassium.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
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. Use the checker below to surface any medication, 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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