blood pressure
33 interactions related to blood pressure
losartan + potassium
Losartan blocks the angiotensin II receptor, lowering aldosterone and reducing the amount of potassium the kidneys excrete. Adding concentrated potassium supplements or potassium-based salt substitutes can push serum potassium toward the hyperkalemic range, which carries cardiac arrhythmia risk in people with kidney impairment, diabetes, or heart failure. Routine monotherapy raises measured potassium only modestly in people with healthy kidneys, but the safety margin narrows once supplements or other potassium-raising drugs are added.
lisinopril + potassium
Lisinopril blocks the renin-angiotensin-aldosterone system, lowering aldosterone and reducing the kidneys' ability to excrete potassium. Adding a potassium supplement or potassium-based salt substitute on top can push blood potassium into a dangerous range (hyperkalemia), especially in older adults or people with reduced kidney function.
lisinopril + salt substitutes
Most popular salt substitutes replace sodium chloride with potassium chloride, delivering a meaningful potassium load with every shake. Lisinopril, an ACE inhibitor, reduces the kidney's ability to excrete potassium. Used together, this combination has caused documented cases of life-threatening hyperkalemia, including emergencies requiring dialysis.
losartan + licorice
Glycyrrhizin in licorice mimics aldosterone, causing the kidneys to retain sodium and water while losing potassium. This pseudoaldosteronism raises blood pressure and works against losartan's antihypertensive effect, and the potassium loss can cause weakness and dangerous heart-rhythm problems.
losartan + hawthorn
Hawthorn modestly lowers blood pressure through vasodilation and endothelial effects. Taken with losartan, an angiotensin II receptor blocker, the two can add up and occasionally cause dizziness or lightheadedness, mainly in people who already run low or who take more than one blood pressure medication.
amlodipine + calcium
In theory, supplemental calcium could slightly blunt the blood-pressure-lowering effect of calcium channel blockers such as amlodipine, but controlled human data do not show a meaningful effect. Drugs.com flags this as a minor, monitor-only interaction with weak clinical evidence.
valsartan + spirulina
Spirulina has a modest blood-pressure-lowering effect in clinical trials and contributes a small amount of potassium. Combined with valsartan, the theoretical concerns are slightly additive blood pressure lowering and a minor contribution to potassium load. At usual supplement amounts neither effect is large, and for people with normal kidney function the combination is generally tolerable.
prednisone + licorice
Glycyrrhizin in real licorice inhibits the enzyme 11-beta-hydroxysteroid dehydrogenase type 2, which normally inactivates cortisol and prednisolone at the kidney's mineralocorticoid receptor. Blocking it produces a pseudohyperaldosteronism state — sodium and water retention, rising blood pressure, and potassium loss. Layered onto prednisone, this can drive clinically significant hypokalemia, and severe cases of hypokalemic paralysis, arrhythmia, and refractory hypertension have been reported.
potassium + magnesium
Magnesium is required for the Na/K-ATPase pump that maintains intracellular potassium, so magnesium deficiency can cause potassium loss that does not correct with potassium alone until magnesium is also replaced. Both minerals independently support healthy blood pressure and cardiac rhythm, though the size of any added benefit from taking them together has not been well studied.
lisinopril + licorice
Glycyrrhizin in licorice mimics aldosterone, causing the kidneys to retain sodium and water and excrete potassium. This raises blood pressure and works against lisinopril's antihypertensive effect, while also lowering potassium, which can complicate cardiovascular risk.
hydrochlorothiazide + potassium
Hydrochlorothiazide promotes urinary potassium excretion at the distal convoluted tubule and is a common cause of drug-induced low potassium (hypokalemia). Many patients stay low even with food or supplements, while others on combination blood-pressure regimens face the opposite risk of high potassium if a potassium-sparing drug is added. Either direction can affect heart rhythm, so potassium should be supplemented only under medical guidance with blood monitoring.
beetroot + vardenafil
Vardenafil blocks PDE5 and prolongs nitric oxide signaling. Beetroot is a major dietary source of nitrate that the body converts to nitric oxide, so concentrated beetroot products can add to vardenafil's blood pressure lowering effect.
amlodipine + grapefruit
Amlodipine is a CYP3A4 substrate, but unlike other dihydropyridine calcium channel blockers such as felodipine and nisoldipine, its high oral bioavailability and slow elimination mean grapefruit juice does not meaningfully alter its pharmacokinetics in controlled trials. Some product labels and consumer references still list a theoretical interaction, but the clinical signal at ordinary dietary intakes is small to negligible.
diltiazem + grapefruit
Grapefruit inhibits intestinal CYP3A4, modestly and unpredictably increasing systemic exposure to diltiazem.
alcohol + venlafaxine
Venlafaxine (Effexor) is an SNRI antidepressant, and alcohol is a central nervous system depressant. The FDA-approved label advises avoiding alcohol because the combination can add to drowsiness and dizziness and can worsen the mood or anxiety disorder being treated. The concern is about additive sedation, blood pressure, and undermined treatment rather than a dramatic pharmacokinetic clash, which is why it is rated moderate.
alcohol + propranolol
Alcohol and propranolol can produce additive drops in blood pressure with dizziness, lightheadedness, and fainting through combined vasodilation and a blunted heart-rate response. Propranolol can also mask the racing-heart and shakiness warning signs of low blood sugar, and alcohol can raise propranolol levels in the body.
alcohol + hydrochlorothiazide
Hydrochlorothiazide and alcohol both lower blood pressure and increase fluid loss, so taking them together can cause additive dizziness, lightheadedness on standing, and fainting. Both can also worsen loss of potassium and magnesium. The interaction is usually manageable at light drinking levels but becomes more significant in older adults, in hot weather, and during illness.
caffeine + propranolol
Caffeine is a stimulant that nudges heart rate and blood pressure upward, partially opposing the direction propranolol works in. The effect is usually modest, but heavy or concentrated caffeine can blunt propranolol's benefit and worsen the tremor or anxiety it is often prescribed to control.
hibiscus tea + hydrochlorothiazide
Hibiscus tea and hydrochlorothiazide both lower blood pressure and act as mild diuretics, so together the effect can be additive on blood pressure and on potassium loss. Animal data also suggest hibiscus may raise hydrochlorothiazide blood levels by reducing its renal clearance, though this has not been confirmed in humans.
oranges + ace inhibitors
Oranges and orange juice are rich in potassium, and ACE inhibitors reduce the kidneys' excretion of potassium by suppressing aldosterone. Drinking large daily volumes of orange juice while taking an ACE inhibitor can nudge serum potassium upward. The risk is real but modest for most people; it matters most in those with reduced kidney function, diabetes, or heart failure, or those also taking other potassium-raising medicines or supplements.
potatoes + ace inhibitors
Potatoes are one of the most concentrated dietary sources of potassium, and ACE inhibitors reduce how much potassium the kidneys excrete by lowering aldosterone. Regularly eating large servings of potatoes while taking an ACE inhibitor can nudge serum potassium upward, especially in people with chronic kidney disease, heart failure, or diabetes, or those taking other potassium-raising medicines.
dark chocolate + blood pressure medications
Cocoa flavanols in dark chocolate boost nitric-oxide-dependent vasodilation and modestly lower blood pressure. On top of antihypertensive medication the effect is additive and usually helpful, but in sensitive people it can occasionally nudge readings low enough to cause light-headedness.
ginseng + caffeine
Ginseng and caffeine are both mild stimulants, so combining them can additively increase alertness, jitteriness, palpitations, or insomnia in sensitive people, though the best evidence shows no meaningful cardiac signal from ginseng itself.
caffeine + adderall
Caffeine and the amphetamine salts in Adderall are both sympathomimetic stimulants. Taking them together adds their effects, so heart rate, blood pressure, jitteriness and trouble sleeping tend to be more pronounced than with either alone.
valsartan + potassium
Valsartan is an angiotensin II receptor blocker that suppresses aldosterone, which slows the kidneys' excretion of potassium. The FDA-approved Diovan label warns that potassium supplements and potassium-containing salt substitutes may raise serum potassium to clinically significant levels, particularly in people with reduced kidney function, diabetes, or heart failure.
celery juice + blood pressure medications
Celery contains phthalides (including 3-n-butylphthalide), nitrate, and potassium that relax blood vessels and have a mild blood-pressure-lowering effect demonstrated in a human trial of celery seed extract. Drinking celery juice regularly can add to the effect of antihypertensive drugs such as ACE inhibitors, ARBs, calcium channel blockers, and diuretics, potentially pushing blood pressure lower than intended.
beetroot + sildenafil
Beetroot is rich in dietary inorganic nitrate, which the body converts to nitric oxide, the same blood-vessel-relaxing pathway that sildenafil (a PDE5 inhibitor) amplifies. The formal contraindication on sildenafil is for organic nitrate drugs, not food, but concentrated beetroot juice and nitrate supplements can lower blood pressure enough that combining them with sildenafil may add to its blood-pressure-lowering effect. This is a mechanism-based caution rather than a documented danger.
caffeine + yohimbine
Caffeine and yohimbine are both stimulants that activate the sympathetic ('fight or flight') nervous system through different routes. Caffeine blocks adenosine receptors and raises catecholamine output; yohimbine blocks alpha-2 adrenergic receptors, increasing norepinephrine release. Taken together they add to each other's effects on heart rate, blood pressure, and anxiety. Yohimbine-containing products have been linked to emergency-department visits and hospitalizations for fast heart rate, high blood pressure, and severe anxiety.
pomegranate + ace inhibitors
Pomegranate juice modestly lowers blood pressure on its own and can add to the blood-pressure-lowering effect of ACE inhibitors; it also contributes dietary potassium, which may compound the potassium-retaining effect of these drugs.
salt substitute + lisinopril
Most salt substitutes replace sodium chloride with potassium chloride, making them a concentrated source of potassium. Lisinopril and other ACE inhibitors lower aldosterone and reduce the kidneys' ability to clear potassium. Used together, they can raise blood potassium to dangerous levels (hyperkalemia), especially in people with reduced kidney function, diabetes, older age, or who take other potassium-raising medicines.
coffee + propranolol
Caffeine in coffee acutely raises heart rate and blood pressure, which can partly counteract the heart-rate and blood-pressure-lowering effects of propranolol, a non-selective beta-blocker. Propranolol does not fully block this caffeine pressor response. Older claims that propranolol slows caffeine clearance appear to be wrong: a human study found propranolol slightly speeds caffeine elimination rather than slowing it.
bananas + lisinopril
Lisinopril is an ACE inhibitor that reduces aldosterone, so the kidneys hold onto more potassium and serum potassium tends to rise. A diet heavy in high-potassium foods like bananas can add to that load. For most people with normal kidneys this is a small, manageable effect; the risk of clinically meaningful hyperkalemia is greater in those with reduced kidney function, diabetes, heart failure, or who also take potassium-sparing diuretics, potassium supplements, or potassium-based salt substitutes.
avocado + ace inhibitors
Avocado is high in potassium, and ACE inhibitors reduce the kidneys' excretion of potassium by lowering aldosterone. Heavy, regular avocado intake combined with an ACE inhibitor — especially alongside other potassium sources or in people with reduced kidney function — can raise serum potassium toward hyperkalemia.