1 interaction related to sympathetic
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.