hypertension
23 interactions related to hypertension
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.
propranolol + melatonin
Propranolol blocks the beta-adrenergic signal the pineal gland uses to make melatonin at night, lowering the body's own nighttime melatonin.
atenolol + calcium
Calcium supplements and calcium-based antacids taken at the same time as atenolol bind it in the gut and reduce how much of the drug is absorbed, blunting its blood-pressure and heart-rate effects. Separating the two doses by several hours preserves atenolol's effect. Calcium from ordinary meals is generally not a concern.
hydrochlorothiazide + magnesium
Thiazide diuretics such as hydrochlorothiazide increase urinary magnesium excretion, and a meaningful minority of long-term users become magnesium-depleted. Low magnesium also makes potassium hard to replace and can worsen muscle cramps and heart-rhythm risk.
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.
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.
metoprolol + melatonin
Metoprolol blocks the beta-1 adrenergic receptors the pineal gland uses to receive its nighttime signal to make melatonin, so it tends to suppress your own melatonin and can contribute to insomnia and vivid dreams. A randomized trial in beta-blocker-treated patients found that low-dose bedtime melatonin improved sleep without interfering with metoprolol's cardiovascular benefits. This is a beneficial, low-concern combination rather than a harmful clash.
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.
propranolol + st. john's wort
St. John's Wort induces several liver drug-metabolizing enzymes, including CYP1A2 and CYP3A4, plus the transporter P-glycoprotein. Propranolol is cleared mainly through CYP1A2 and CYP2D6, so regular St. John's Wort use can plausibly speed up its breakdown and weaken its effect. Direct studies of this specific pair are lacking; the concern is based on St. John's Wort's confirmed enzyme-inducing action, its documented lowering of theophylline (which shares propranolol's CYP1A2 pathway), and a case report of lost intraocular-pressure control in a glaucoma patient on a topical beta-blocker.
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.
cayenne + ace inhibitors
Capsaicin, the active compound in cayenne, acts on the same airway cough receptors that ACE inhibitors sensitize, so it may trigger or worsen the dry cough some people get on ACE inhibitor therapy. The evidence is a single older case report plus consistent mechanism; the effect is a nuisance, not a danger, and cayenne does not reduce how well the medication works.
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.
smoking + propranolol
Cigarette smoking induces hepatic metabolism of propranolol (mainly via CYP1A2 and glucuronidation), increasing its clearance and lowering propranolol blood levels in smokers compared with non-smokers. Nicotine also independently raises heart rate, blood pressure, and circulating catecholamines, partly counteracting propranolol's beta-blocking effect. Both effects reverse when a person quits smoking.
lithium + ace inhibitors
ACE inhibitors lower the rate at which the kidneys clear lithium, so adding one to lithium therapy tends to raise serum lithium levels. Because lithium has a narrow safety margin, this can push levels toward the toxic range. A distinctive feature is delayed onset: toxicity may not appear for several weeks after the ACE inhibitor is started, especially in older adults and those with reduced kidney function.
energy drinks + beta-blockers
Energy drinks and beta-blockers exert opposing cardiovascular effects: beta-blockers slow heart rate and lower blood pressure, while the caffeine and stimulant load in energy drinks pushes the sympathetic system the other way. This can blunt the medication's effect and, in susceptible people, help provoke an arrhythmia.
energy drinks + adderall
Energy drinks deliver caffeine alongside other stimulant ingredients such as taurine and guarana, producing additive sympathomimetic effects on top of the amphetamine salts in Adderall. Both raise heart rate, blood pressure, and adrenergic activity, which can bring on palpitations, elevated blood pressure, anxiety, and insomnia, and in rare cases more serious heart rhythm disturbances.
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.
garlic + hawthorn
Garlic and hawthorn each modestly lower blood pressure on their own, and both have mild blood-thinning activity, so taking them together can add up to a slightly larger drop in blood pressure and a small increase in bleeding tendency. There is no human trial of the two taken together, so any true 'synergy' beyond simple additive effects is unproven. The practical concern is layering them on top of antihypertensive, antiplatelet, or anticoagulant medication.
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.
spironolactone + licorice
Glycyrrhizin in licorice is converted to glycyrrhetinic acid, which inhibits the kidney enzyme 11-beta-hydroxysteroid dehydrogenase type 2. This lets cortisol stimulate the mineralocorticoid receptor - the same receptor spironolactone is designed to block. The two pull in opposite directions: licorice tends to raise blood pressure and lower potassium, while spironolactone lowers blood pressure and raises potassium, so the herb can partially blunt the drug's intended effect.