blood pressure
34 interactions related to blood pressure
losartan + potassium
Losartan blocks the angiotensin II receptor, lowering aldosterone and reducing renal potassium excretion in the same way ACE inhibitors do. Concurrent potassium supplementation can drive serum potassium into the hyperkalemic range, with cardiac arrhythmia risk in patients with kidney impairment, diabetes, or heart failure.
lisinopril + potassium
Lisinopril blocks the renin-angiotensin-aldosterone system, reducing aldosterone secretion and impairing the kidneys' ability to excrete potassium. Adding potassium supplements on top of this can push serum potassium into dangerous territory, especially in older adults or those with reduced kidney function.
lisinopril + salt substitutes
Potassium-based salt substitutes (potassium chloride replacing sodium chloride) can deliver hundreds of milligrams of potassium per teaspoon. Combined with lisinopril's impairment of renal potassium excretion, this combination has caused multiple documented cases of life-threatening hyperkalemia, including cardiac arrest.
losartan + licorice
Glycyrrhizin in licorice mimics aldosterone, causing renal sodium and water retention and potassium loss. This pseudoaldosteronism raises blood pressure and counteracts losartan's antihypertensive effect, while also producing hypokalemia that can cause weakness and arrhythmia.
losartan + hawthorn
Hawthorn produces modest blood pressure lowering (roughly 5 to 11 mmHg systolic in clinical trials) through vasodilation and mild ACE-like activity. Combined with losartan, the additive effect could occasionally cause hypotension or dizziness, particularly in people on multiple antihypertensives or those starting hawthorn at high doses.
amlodipine + calcium
Theoretically, high doses of supplemental calcium could blunt the vasodilatory effect of calcium channel blockers such as amlodipine, but controlled human data are limited. Drugs.com flags this as a minor monitor-only interaction with weak clinical evidence.
valsartan + spirulina
Spirulina has modest antihypertensive effects in clinical trials (systolic drop of around 4-5 mmHg) and contains roughly 14 mg of potassium per gram. Combined with valsartan, theoretical risks include additive blood pressure lowering and a minor contribution to potassium load, though at typical supplement doses neither effect is large.
prednisone + licorice
Glycyrrhizin in licorice inhibits the enzyme 11-beta-hydroxysteroid dehydrogenase type 2, prolonging the half-life of glucocorticoids and dramatically amplifying mineralocorticoid effects. The combination potentiates sodium retention, hypertension, and hypokalemia, and has been linked to severe hypokalemic crises.
potassium + magnesium
Magnesium is required for the Na/K-ATPase pump that maintains intracellular potassium, so magnesium deficiency causes refractory potassium loss that cannot be corrected by potassium alone. Co-supplementation of the two minerals produces additive reductions in systolic blood pressure and supports normal cardiac rhythm.
lisinopril + licorice
Glycyrrhizin in licorice mimics aldosterone, causing the kidneys to retain sodium and water and excrete potassium. This raises blood pressure and directly opposes lisinopril's antihypertensive effect, while also driving hypokalemia that can complicate other cardiovascular risks.
hydrochlorothiazide + potassium
Hydrochlorothiazide promotes urinary potassium excretion at the distal convoluted tubule and is a leading cause of drug-induced hypokalemia. Many patients still develop low potassium despite supplementation, while some on combination antihypertensives risk the opposite problem if a potassium-sparing agent is added.
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 dihydropyridines (felodipine, 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.
diltiazem + grapefruit
Grapefruit juice inhibits intestinal CYP3A4 and increases diltiazem exposure (AUC) by roughly 20% in healthy volunteers, with high inter-individual variability. The increase can amplify the drug's negative chronotropic and hypotensive effects.
radish + ace inhibitors
Radish contains moderate amounts of dietary nitrate and potassium. Nitrate becomes nitric oxide and modestly relaxes blood vessels, while potassium adds to the elevated potassium levels that ACE inhibitors already cause. In normal food portions the effect is small, but very large or supplement-level intake can matter.
alcohol + venlafaxine
Venlafaxine (Effexor) is an SNRI that, like other antidepressants, has additive CNS-depressant effects with alcohol. The FDA-approved label warns patients to avoid alcohol because of worsening drowsiness, dizziness, impaired judgment, and the potential to aggravate the underlying mood or anxiety disorder.
alcohol + propranolol
Alcohol and propranolol can produce additive hypotension, dizziness, and sedation through combined vasodilation and central nervous system depression; propranolol also masks the warning symptoms of low blood sugar and rapid heart rate. Chronic heavy drinking induces hepatic enzymes and can reduce propranolol effectiveness.
alcohol + hydrochlorothiazide
Hydrochlorothiazide and alcohol both lower blood pressure and promote dehydration; combined use causes additive hypotension, dizziness, and orthostatic syncope, especially on standing or in hot weather. The combination also worsens electrolyte loss, particularly potassium and magnesium.
caffeine + propranolol
Caffeine raises systemic vascular resistance and heart rate, partially opposing propranolol's blood-pressure and heart-rate lowering effects. High caffeine intake can also worsen tremor and anxiety that propranolol is prescribed to treat.
hibiscus tea + hydrochlorothiazide
Hibiscus (Hibiscus sabdariffa) has intrinsic diuretic and antihypertensive activity and animal studies show it increases serum levels of hydrochlorothiazide while reducing its clearance. The combination can produce additive blood pressure lowering and amplified electrolyte loss including hypokalemia.
oranges + ace inhibitors
Oranges and orange juice are high in potassium (about 240 mg per medium orange, 450-500 mg per cup of juice), and ACE inhibitors reduce aldosterone and renal potassium excretion. Heavy consumption of oranges or orange juice with ACE inhibitors can raise serum potassium, with greater risk in patients with reduced kidney function.
potatoes + ace inhibitors
Potatoes are very high in potassium (a medium baked potato with skin contains about 900 mg), and ACE inhibitors reduce aldosterone-mediated potassium excretion. Regular large servings of potatoes combined with ACE inhibitors can raise serum potassium, particularly in patients with chronic kidney disease, heart failure, or diabetes.
dark chocolate + blood pressure medications
Dark chocolate flavanols improve nitric-oxide-dependent vasodilation and modestly lower systolic and diastolic blood pressure (typically 2–3 mmHg). Combined with antihypertensives, this can additively lower blood pressure, occasionally producing symptoms of hypotension such as dizziness in sensitive patients.
ginseng + caffeine
Panax ginseng has its own mild stimulant and sympathomimetic activity that adds to caffeine's effects on heart rate, blood pressure, and CNS arousal. The combination can produce jitteriness, insomnia, palpitations, anxiety, and elevated blood pressure, with greater risk in people with hypertension, arrhythmia, or anxiety disorders.
caffeine + adderall
Caffeine and amphetamine salts are both sympathomimetic stimulants. Combining them raises heart rate and blood pressure, worsens anxiety and insomnia, and increases the risk of palpitations, arrhythmias and panic attacks.
valsartan + potassium
Valsartan is an angiotensin II receptor blocker that suppresses aldosterone and slows renal potassium excretion. The FDA-approved Diovan label specifically warns that potassium supplements and potassium-containing salt substitutes may lead to clinically significant hyperkalemia, particularly in patients with renal impairment, diabetes, or heart failure.
celery juice + blood pressure medications
Celery contains phthalides (including 3-n-butylphthalide), nitrate, and other constituents that relax vascular smooth muscle and have demonstrated blood pressure lowering effects in animal and small human studies. Large daily celery juice intake can add to the effect of antihypertensive drugs, including ACE inhibitors, calcium channel blockers, and diuretics.
beetroot + sildenafil
Beetroot is high in dietary inorganic nitrate that the body converts to nitric oxide, the same vasodilator pathway amplified by PDE5 inhibitors like sildenafil. While organic nitrate drugs (not dietary) are the formal contraindication, large doses of beetroot juice can meaningfully lower blood pressure and may add to sildenafil's vasodilatory effect.
caffeine + yohimbine
Caffeine and yohimbine are both potent stimulants. Yohimbine blocks alpha-2 adrenergic receptors, raising norepinephrine, while caffeine blocks adenosine receptors and amplifies sympathetic output. Combined, they can cause large rises in heart rate and blood pressure, severe anxiety, tremor, panic attacks, arrhythmias, and have been linked to hospital visits and rare cardiovascular events.
pomegranate + ace inhibitors
Pomegranate polyphenols (pedunculagin, punicalin, gallagic acid) directly inhibit angiotensin-converting enzyme, and clinical trials show pomegranate juice lowers systolic and diastolic blood pressure on its own. Combined with prescription ACE inhibitors the effects can stack, potentially causing additive hypotension, dizziness, or hyperkalemia.
salt substitute + lisinopril
Salt substitutes are typically potassium chloride and can deliver hundreds of milligrams of potassium per small serving. Lisinopril and other ACE inhibitors reduce aldosterone and decrease potassium excretion. Combining them can cause clinically significant hyperkalemia, particularly with chronic kidney disease, diabetes, or other potassium-raising drugs.
coffee + propranolol
Caffeine in coffee acutely raises heart rate and blood pressure, which can counteract the heart-rate and blood-pressure-lowering effects of propranolol, a non-selective beta-blocker. Propranolol may also slow caffeine clearance modestly, increasing caffeine exposure.
bananas + lisinopril
Lisinopril is an ACE inhibitor that reduces aldosterone and increases serum potassium. Combined with high dietary potassium from bananas and other potassium-rich foods, this can cause hyperkalemia, particularly in patients with reduced kidney function or those also taking potassium-sparing diuretics.
avocado + ace inhibitors
Avocados are a high-potassium food (about 487 mg per half avocado), and ACE inhibitors reduce aldosterone-driven potassium excretion. Frequent large servings of avocado combined with ACE inhibitors can contribute to hyperkalemia, especially in patients with kidney impairment or other potassium-raising medications.