Beta-Blockers Interactions

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.

CBD inhibits several CYP450 enzymes (notably CYP3A4, CYP2C19, CYP2C9, CYP1A2) and may modestly inhibit CYP2D6. Beta-blockers such as metoprolol, propranolol, and carvedilol are metabolized via CYP2D6 (and CYP1A2 for propranolol), so co-use can raise beta-blocker plasma levels, with additive blood-pressure lowering and bradycardia.