Adenosine is a chemical found in the body that plays a role in inducing sleep. It accumulates in the brain over the course of the day, binding to adenosine receptors and causing drowsiness. Episode 919: EKG Criteria for Adenosine discusses how adenosine can also be used as a medication to treat supraventricular tachycardia (SVT) by blocking AV nodal conduction.
How does coffee keep you awake? explores how the caffeine in coffee blocks the sleep-inducing effects of adenosine, leading to heightened alertness and increased adrenaline production. However, the episode also cautions that regular caffeine consumption can lead to a tolerance over time.