hypertension
23 interactions related to hypertension
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.
propranolol + melatonin
Propranolol blocks pineal beta-1 adrenergic receptors that control endogenous melatonin synthesis, suppressing nighttime melatonin levels by roughly 50% and contributing to insomnia, vivid dreams, and reduced sleep efficiency. Low-dose oral melatonin at bedtime can restore sleep architecture without compromising propranolol's antihypertensive effect.
atenolol + calcium
Calcium salts taken together with atenolol form a complex in the gut that cuts atenolol's peak plasma level by roughly 51% and total exposure (AUC) by 32%, blunting its blood-pressure and heart-rate effects 12 hours later. The effect was first quantified in a 1981 pharmacokinetic study and is the main reason high-dose calcium and atenolol should be separated in time.
hydrochlorothiazide + magnesium
Thiazide diuretics increase urinary magnesium excretion and roughly 1 in 5 long-term users develop hypomagnesemia. Low magnesium worsens the hypokalemia that thiazides also cause and can perpetuate refractory potassium depletion.
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.
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.
metoprolol + melatonin
Metoprolol blocks the beta-1 adrenergic receptors that drive pineal melatonin synthesis, suppressing endogenous nighttime melatonin and contributing to insomnia, vivid dreams, and reduced sleep efficiency. Low-dose oral melatonin can restore sleep without interfering with metoprolol's cardiovascular benefits.
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.
propranolol + st. john's wort
St. John's Wort potently induces CYP1A2 and CYP2C19 along with CYP3A4 and P-glycoprotein, accelerating the metabolism of propranolol and reducing its plasma levels. Documented cases include loss of intraocular pressure control in glaucoma patients on topical beta-blockers, and the mechanism predicts similar loss of antihypertensive and antiarrhythmic effect with systemic propranolol.
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.
cayenne + ace inhibitors
Capsaicin, the active component of cayenne, can trigger or worsen the dry cough characteristic of ACE inhibitor therapy by sensitizing airway cough receptors. A published case report describes topical capsaicin inducing cough in a patient already on an ACE inhibitor.
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.
smoking + propranolol
Cigarette smoking induces hepatic metabolism of propranolol via CYP1A2 and accelerated glucuronidation, increasing apparent oral clearance and reducing propranolol plasma concentrations in smokers compared with non-smokers. Nicotine also independently raises heart rate, blood pressure, and circulating catecholamines, partially counteracting propranolol's beta-blocking effect.
lithium + ace inhibitors
ACE inhibitors reduce glomerular filtration rate and decrease sodium delivery to the distal nephron, which lowers renal lithium clearance and can raise serum lithium by approximately 36 percent. Toxicity may emerge with delayed onset 3 to 5 weeks after starting the ACE inhibitor, particularly in older adults and those with reduced renal function.
energy drinks + beta-blockers
Energy drinks raise sympathetic tone through caffeine, taurine, and guarana, opposing the heart-rate and blood-pressure lowering effects of beta-blockers like metoprolol, atenolol, propranolol, and bisoprolol. Case reports document refractory arrhythmias and hypertensive episodes in patients on beta-blocker therapy who consumed energy drinks regularly.
energy drinks + adderall
Energy drinks deliver high-dose caffeine (often 80-300 mg per can) plus taurine, guarana, and B vitamins that produce additive sympathomimetic effects on top of the amphetamine salts in Adderall. Both substances raise heart rate, blood pressure, and norepinephrine release, which can precipitate palpitations, hypertension, anxiety, insomnia, and in rare cases tachyarrhythmia or coronary vasospasm.
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.
garlic + hawthorn
Aged garlic extract lowers blood pressure through endothelial nitric oxide release, mild ACE inhibition, and antioxidant effects, while hawthorn flavonoids provide vasodilation, mild positive inotropy, and improved coronary flow. Together they act on complementary aspects of vascular tone and cardiac function in mild hypertension.
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.
spironolactone + licorice
Glycyrrhizin in licorice blocks 11-beta-hydroxysteroid dehydrogenase type 2 and activates mineralocorticoid receptors - the same receptors that spironolactone is designed to block. The two work in opposite directions: licorice raises blood pressure and lowers potassium while spironolactone lowers blood pressure and raises potassium, so the herb partially undoes the drug's intended therapeutic effect.