beta-blocker
9 interactions related to beta-blocker
metoprolol + coq10
Beta-blockers like metoprolol inhibit CoQ10-dependent mitochondrial enzymes, gradually depleting CoQ10 levels in heart tissue and potentially contributing to fatigue, exercise intolerance, and reduced cardiac energy production. CoQ10 supplementation does not reduce metoprolol's blood pressure or heart rate effects but may offset these mitochondrial side effects.
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.
metoprolol + hawthorn
Hawthorn (Crataegus) has mild vasodilatory and positive inotropic effects that can additively lower blood pressure and slow heart rate when combined with metoprolol, increasing the risk of hypotension, bradycardia, dizziness, or syncope. The interaction is pharmacodynamic, not metabolic, so spacing the doses does not prevent it.
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.
carvedilol + st. john's wort
Carvedilol is metabolized by CYP2D6, CYP2C9, CYP3A4, and CYP1A2, and is also a P-glycoprotein substrate. St. John's Wort potently induces several of these enzymes and P-gp, accelerating carvedilol clearance and reducing plasma levels, which can blunt its heart failure and antihypertensive effects.
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.
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.
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.
black pepper + propranolol
Piperine, the active alkaloid in black pepper, inhibits CYP3A4, CYP2C9, and intestinal P-glycoprotein, increasing the oral bioavailability and serum concentration of propranolol and other beta-blockers, which can amplify blood pressure and heart rate reduction.